Dismantling David Ley's Response to Philip Zimbardo: "We Must Rely on Good Science in Porn Debate"

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The following is YBOP's response to David Ley's Psychology Today blog post "We Must Rely on Good Science in Porn Debate (2016)." Ley's post is his response to Philip Zimbardo's Psychology Today blog post "Is Porn Good For Us or Bad For Us?" (2016).

While Ley's title says we must rely on "good science," it is Ley who links to only a single paper (which actually supports the concept of porn addiction). In contrast, Zimbardo provides 14 references (13 studies, one article) and a link to his new book "Man, Interrupted: Why Young Men are Struggling & What We Can Do About It". Zimbardo could have cited many more studies, as you will see.

Ley Links to Only a Single Citation, and It Supports Porn Addiction

Ley provides plenty of bluster, but there's not a single citation in Ley's post that refutes anything in Zimbardo's post. In fact, Ley's article links to only one citation - which is a recent review of the literature on compulsive sexual behaviors, by Shane Kraus, Valerie Voon & Marc Potenza. Contrary to Ley's claim, the "Voon review" actually supports the existence of porn addiction. An excerpt from the review: 

"Overlapping features exist between CSB [compulsive sexual behavior] and substance use disorders. Common neurotransmitter systems may contribute to CSB and substance use disorders, and recent neuroimaging studies highlight similarities relating to craving and attentional biases."

In other words, the research on CSBs has much in common with substance abuse disorders, even if cautious scientists want to see further evidence. Two of the authors of this review (Valerie Voon & Marc Potenza) are top addiction neuroscientists. Together they have published three studies on "porn addicts." Two of the studies were fMRIs (brain scans), while one was neuropsychological (attentional bias). While Voon and Potenza tend to be very guarded, they stated that their three brain studies align perfectly with the addiction model (1, 2, 3). Ley ignores all of this and excerpts the cautious portion of the paper, which is a normal feature of serious scientific papers. Then he interprets it for us, claiming it means the data is conflicted (rather than merely still limited):

“Insufficient data are available regarding what clusters of symptoms may best constitute CSB (Compulsive Sexual Behavior) or what threshold may be most appropriate for defining CSB. Such insufficient data complicate classification, prevention and treatment efforts. While neuroimaging data suggest similarities between substance addictions and CSB, data are limited by small sample sizes, solely male heterosexual samples, and cross-sectional design.”

Read the above carefully. Yes, the researchers want more data. (They always do.) However, Kraus, Voon and Potenza clearly state that the existing data points for substance addictions and CSBs are neurobiologically similar. Simply put, drug addictions and compulsive sexual behaviors share similar neurobiological features and brain changes. By the way, nearly all the brain studies cited in this review to demonstrate that CSBs are very similar to substance abuse disorders involved compulsive internet porn users. It's not surprising as a separate review (Neurobiology of Compulsive Sexual Behavior: Emerging Science. 2016) published a month earlier by Kraus, Voon and Potenza concluded:

"Given some similarities between CSB and drug addictions, interventions effective for addictions may hold promise for CSB, thus providing insight into future research directions to investigate this possibility directly."

In other words, the conflict does not lie in the neuroscience on porn addicts, which is clear, and very similar to that on substance abusers. Instead, the conflict surrounds what "cluster of symptoms" best defines compulsive sexual behaviors (CSB). The difficulty agreeing on a cluster of symptoms arises from the fact that the researchers fail to tease apart sex addiction from Internet porn addiction, lumping them together as "CSBs."

All 37 Neuroscience-Based Studies on Porn Users Support Zimbardo's Claim; None support Ley's

There's a reason that Ley provided zero studies while Zimbardo tucked in 13. Truth be told, Zimabardo could have cited 20 more neuroscience-based studies on CSB subjects. Put simply, Ley's post omitted all 37 neuroscience-based studies on porn users that have been published in the last few years (up-to-date list). So far, the results of every "brain study" (MRI, fMRI, EEG, neuropsychological, neuro-endocrine) offer support for the concept of porn addiction. In addition to reporting the same fundamental brain changes as seen in substance addicts, a few studies also reported that greater porn use is associated with erectile dysfunction, decreased libido, anorgasmia, delayed ejaculation, and reduced neural response to images of vanilla porn.

The 37 studies on porn users also align with over 250 internet addiction "brain studies" (PET, MRI, fMRI, EEG) published in the last few years. Without exception, these studies report the same addiction-related brain changes as seen in substance addicts. Internet porn addiction is, according to various experts, a subtype of internet addiction as well as a CSB, as this recent review of the neuroscience literature pointed out: "Neuroscience of Internet Pornography Addiction: A Review and Update (2015)." Also see Sex Addiction as a Disease: Evidence for Assessment, Diagnosis, and Response to Critics (2015), which provides a chart that takes on specific criticisms and offers citations that counter them.

Addressing Specific Claims in Ley's Blog Post

LEY: "Dr. Zimbardo goes on to cite several studies and articles which have alleged that pornography has a neurological effect. Unfortunately, there’s the problem of causation versus correlation, again, something I learned about in basic research classes."

RESPONSE: This single sentence demonstrates a profound lack of knowledge as to how research works.

When someone uses "no causation has been demonstrated" it makes listening scientists doubt that person's basic understanding of science or research. When it comes to psychological and medical studies little research reveals causation directly. For example, all studies on the relationship between lung cancer and cigarette smoking are correlative - but cause and effect are settled.

In light of ethical requirements researchers are usually precluded from constructing experimental research designs which would prove pornography causes certain harms. Therefore, they must instead use correlational models. Over time, when a significant body of correlational studies are amassed in any given research area, there comes a point where the body of evidence can be said to prove a point of theory, even though there were no experimental studies. Put another way, no single correlation study could ever provide a “smoking gun” in an area of study, but the converging evidence of multiple correlational studies is used to establish evidence. When it comes to porn use, nearly every study published is correlative. To "prove" porn use is causing erectile dysfunction or addiction-related brain changes you would have to do one of two things:

  1. Have two large groups of identical twins separated at birth. Make sure one group never watches porn. Make sure that every individual in the other group watches the exact same type of porn, for exact same hours, and the exact same age. Continue the experiment for 30 years or so, followed by assessment of the differences.
  2. Eliminate the variable whose effects you wish to measure. Specifically, have porn users stop, and assess the changes months (years?) later. This is exactly what is occurring informally online as thousands of young men stop internet porn use to alleviate chronic non-organic sexual dysfunctions (that turn out to have been caused by porn use).

To this date only 8 studies have removed porn and observed the results. All 8 found significant changes.  Five of those studies had compulsive porn users with severe sexual dysfunctions abstain from porn. Those 5 studies demonstrate causation as patients healed chronic sexual dysfunctions by removing a single variable: porn. The 8 studies:

1) Trading Later Rewards for Current Pleasure: Pornography Consumption and Delay Discounting (2015) – This study reported that greater porn use was correlated with less ability to delay gratification. The researchers assessed porn users a month later and found that continued porn use correlated with less ability to delay gratification. Finally, researchers divided subjects into 2 groups: Half tried to abstain from their favorite food; half tried to abstain from internet porn. The subjects who tried to abstain from porn experienced significant changes: they scored better on their ability to delay gratification. The researchers said:

"The finding suggests that Internet pornography is a sexual reward that contributes to delay discounting differently than other natural rewards. It is therefore important to treat pornography as a unique stimulus in reward, impulsivity, and addiction studies and to apply this accordingly in individual as well as relational treatment.”

2) A Love That Doesn’t Last: Pornography Consumption and Weakened Commitment to One’s Romantic Partner (2012) – The study had subjects try to abstain from porn use for 3 weeks. Upon comparing the two groups, those who continued using pornography reported lower levels of commitment than those who tried to abstain.

3) Unusual masturbatory practice as an etiological factor in the diagnosis and treatment of sexual dysfunction in young men (2014) – One of the 4 case studies in this article reports on a man with porn-induced sexual problems (low libido, fetishes, anorgasmia). The sexual intervention called for a 6-week abstinence from porn and masturbation. After 8 months the man reported increased sexual desire, successful sex and orgasm, and enjoying “good sexual practices. Excerpts from the paper:

"When asked about masturbatory practices, he reported that in the past he had been masturbating vigorously and rapidly while watching pornography since adolescence. The pornography originally consisted mainly of zoophilia, and bondage, domination, sadism, and masochism, but he eventually got habituated to these materials and needed more hardcore pornography scenes, including transgender sex, orgies, and violent sex. He used to buy illegal pornographic movies on violent sex acts and rape and visualized those scenes in his imagination to function sexually with women. He gradually lost his desire and his ability to fantasize and decreased his masturbation frequency."

In conjunction with weekly sessions with a sex therapist, the patient was instructed to avoid any exposure to sexually explicit material, including videos, newspapers, books, and internet pornography.

After 8 months, the patient reported experiencing successful orgasm and ejaculation. He renewed his relationship with that woman, and they gradually succeeded in enjoying good sexual practices.

4) Is Internet Pornography Causing Sexual Dysfunctions? A Review with Clinical Reports (2016) - An extensive review of the literature related to porn-induced sexual problems. Involving US Navy doctors, the review provides the latest data revealing a tremendous rise in youthful sexual problems. It also reviews the neurological studies related to porn addiction and sexual conditioning via Internet porn. The doctors provide 3 clinical reports of men who developed porn-induced sexual dysfunctions. Two of the three men healed their sexual dysfunctions by eliminating porn use. The third man experienced little improvement as he was unable to abstain from porn use.

Traditional factors that once explained men’s sexual difficulties appear insufficient to account for the sharp rise in erectile dysfunction, delayed ejaculation, decreased sexual satisfaction, and diminished libido during partnered sex in men under 40. This review (1) considers data from multiple domains, e.g., clinical, biological (addiction/urology), psychological (sexual conditioning), sociological; and (2) presents a series of clinical reports, all with the aim of proposing a possible direction for future research of this phenomenon. Alterations to the brain's motivational system are explored as a possible etiology underlying pornography-related sexual dysfunctions. This review also considers evidence that Internet pornography’s unique properties (limitless novelty, potential for easy escalation to more extreme material, video format, etc.) may be potent enough to condition sexual arousal to aspects of Internet pornography use that do not readily transition to real-life partners, such that sex with desired partners may not register as meeting expectations and arousal declines. Clinical reports suggest that terminating Internet pornography use is sometimes sufficient to reverse negative effects, underscoring the need for extensive investigation using methodologies that have subjects remove the variable of Internet pornography use.

5) Male masturbation habits and sexual dysfunctions (2016) - It's by a French psychiatrist who is the current president of the European Federation of Sexology. While the abstract shifts back and forth between Internet pornography use and masturbation, it's clear that he's mostly referring to porn-induced sexual dysfunctions (erectile dysfunction and anorgasmia). The paper revolves around his clinical experience with 35 men who developed erectile dysfunction and/or anorgasmia, and his therapeutic approaches to help them. The author states that most of his patients used porn, with several being addicted to porn. The abstract points to internet porn as the primary cause of the problems (keep in mind that masturbation does not cause chronic ED, and it is never given as a cause of ED). Excerpts:

Intro: Harmless and even helpful in his usual form widely practiced, masturbation in its excessive and pre-eminent form, generally associated today to pornographic addiction, is too often overlooked in the clinical assessment of sexual dysfunction it can induce.

Results: Initial results for these patients, after treatment to “unlearn” their masturbatory habits and their often associated addiction to pornography, are encouraging and promising. A reduction in symptoms was obtained in 19 patients out of 35. The dysfunctions regressed and these patients were able to enjoy satisfactory sexual activity.

Conclusion: Addictive masturbation, often accompanied by a dependency on cyber-pornography, has been seen to play a role in the etiology of certain types of erectile dysfunction or coital anejaculation. It is important to systematically identify the presence of these habits rather than conduct a diagnosis by elimination, in order to include habit-breaking deconditioning techniques in managing these dysfunctions.

6) How difficult is it to treat delayed ejaculation within a short-term psychosexual model? A case study comparison (2017) - A report on two "composite cases" illustrating the causes and treatments for delayed ejaculation (anorgasmia). "Patient B" represented several young men treated by the therapist. Interestingly, the paper states that Patient B's "porn use had escalated into harder material", "as is often the case". The paper says that porn-related delayed ejaculation is not uncommon, and on the rise. The author calls for more research on porn's effects of sexual functioning. Patient B's delayed ejaculation was healed after 10 weeks of no porn. Excerpts:

The cases are composite cases taken from my work within the National Health Service in Croydon University Hospital, London. With the latter case (Patient B), it is important to note that the presentation reflects a number of young males who have been referred by their GPs with a similar diagnosis. Patient B is a 19-year-old who presented because he was unable to ejaculate via penetration. When he was 13, he was regularly accessing pornography sites either on his own through internet searches or via links that his friends sent him. He began masturbating every night while searching his phone for image…If he did not masturbate he was unable to sleep. The pornography he was using had escalated, as is often the case (see Hudson-Allez, 2010), into harder material (nothing illegal)…

We agreed that he would no longer use pornography to masturbate. This meant leaving his phone in a different room at night. We agreed that he would masturbate in a different way….

Patient B was able to achieve orgasm via penetration by the fifth session; the sessions are offered fortnightly in Croydon University Hospital so session five equates to approximately 10 weeks from consultation. He was happy and greatly relieved. In a three-month follow-up with Patient B, things were still going well.

Patient B is not an isolated case within the National Health Service (NHS) and in fact young men in general accessing psychosexual therapy, without their partners, speaks in itself to the stirrings of change.

7) Situational Psychogenic Anejaculation: A Case Study (2014) - The details reveal a case of porn-induced anejaculation. The husband's only sexual experience prior to marriage was frequent masturbation to pornography - where he was able to ejaculate. He also reported sexual intercourse as less arousing than masturbation to porn. The key piece of information is that "re-training" and psychotherapy failed to heal his anejaculation. When those interventions failed, therapists suggested a complete ban on masturbation to porn. Eventually this ban resulted in successful sexual intercourse and ejaculation with a partner for the first time in his life. A few excerpts:

A is a 33-year-old married male with heterosexual orientation, a professional from a middle socio-economic urban background. He has had no premarital sexual contacts. He watched pornography and masturbated frequently. His knowledge about sex and sexuality was adequate. Following his marriage, Mr. A described his libido as initially normal, but later reduced secondary to his ejaculatory difficulties. Despite thrusting movements for 30-45 minutes, he had never been able to ejaculate or achieve orgasm during penetrative sex with his wife.

What didn't work:

Mr. A's medications were rationalized; clomipramine and bupropion were discontinued, and sertraline was maintained at a dose of 150 mg per day. Therapy sessions with the couple were held weekly for the initial few months, following which they were spaced to fortnightly and later monthly. Specific suggestions including focusing on sexual sensations and concentrating on the sexual experience rather than ejaculation were used to help reduce performance anxiety and spectatoring. Since problems persisted despite these interventions, intensive sex therapy was considered.

Eventually they instituted a complete ban on masturbation (which means he continued to masturbate to porn during the above failed interventions):

A ban on any form of sexual activity was suggested. Progressive sensate focus exercises (initially non-genital and later genital) were initiated. Mr. A described an inability to experience the same degree of stimulation during penetrative sex as compared to that which he experienced during masturbation. Once the ban on masturbation was enforced, he reported an increased desire for sexual activity with his partner.

After an unspecified amount of time, the ban on masturbation to porn lead to success:

Meanwhile, Mr. A and his wife decided to go ahead with Assisted Reproductive Techniques (ART) and underwent two cycles of intrauterine insemination. During a practice session, Mr. A ejaculated for the first time, following which he has been able to ejaculate satisfactorily during a majority of the couple's sexual interactions.

8) How Abstinence Affects Preferences (2016) [preliminary results] – Excerpts from the article:

Results of the First Wave - Main Findings

  1. The length of the longest streak participants performed before taking part in the survey correlates with time preferences. The second survey will answer the question if longer periods of abstinence render participants more able to delay rewards, or if more patient participants are more likely to perform longer streaks.
  2. Longer periods of abstinence most likely cause less risk aversion (which is good). The second survey will provide the final proof.
  3. Personality correlates with length of streaks. The second wave will reveal if abstinence influences personality or if personality can explain variation in the length of streaks.

Results of the Second Wave - Main Findings

  1. Abstaining from pornography and masturbation increases the ability to delay rewards
  2. Participating in a period of abstinence renders people more willing to take risks
  3. Abstinence renders people more altruistic
  4. Abstinence renders people more extroverted, more conscientious, and less neurotic

LEY: "Numerous studies have now demonstrated that high porn-users tend to be people with higher libido"

RESPONSE: There's a reason Ley provides no citation. Study after study refutes this often repeated Ley meme. 

Ley's "higher libido" claim appears to based on his blog post with the catchy title: "Your Brain on Porn - It's NOT Addictive". The Ley blog post is not about the science behind YBOP. Instead, it's about a single EEG study, whose lead author is his colleague Nicole Prause: (Steele et al. 2013). Both Ley and Prause claimed that the study's findings support the premise that porn/sex addiction is nothing more than "high sexual desire."

Contrary to claims by Ley and Prause, Steele et al. reported greater cue-reactivity to porn correlating with LESS desire for sex with a partner (but not lower desire to masturbate to porn). To put it another way - individuals with more brain activation and cravings for porn would rather masturbate to porn than have sex with a real person. This is not an indication of "high sexual desire."

Greater cue reactivity to porn coupled with lower desire for sex with real partners aligns the 2014 Cambridge University brain study on porn addicts. The actual findings of Steele et al., 2013 do not support its conclusion, or Ley's blog post assertions. Five subsequent peer-reviewed papers say that the Steele et al. findings actually lend support to the porn addiction model (as opposed to the "high sexual desire" hypothesis) 1, 2, 3, 4, 5.

In 2015, Nicole Prause published a second EEG study, which found LESS neural response (with brief exposure to still images) in “porn addicts” when compared to controls (Steele et al., 2013 had no control subjects) This is evidence of abnormally reduced desire in porn addicts. These findings align perfectly with Kühn & Gallinat (2014), which found that more porn use correlated with less brain activation in response to pictures of vanilla porn. In other words, "porn addicts" were desensitized and - far from having high sexual desire - needed greater stimulation than non-addicts to be turned on. Put simply, the results of Prause's second EEG study indicate LESS sexual arousal - not higher sexual desire. Six peer-reviewed papers all agree that Prause et al., 2015 actually found desensitization/habituation in frequent porn users: 1, 2, 3, 4. 5, 6.

In fact, Prause stated in this recent Quora post that she no longer believes that "sex addicts" have high libidos:

"I was partial to the high sex drive explanation, but this LPP study we just published is persuading me to be more open to sexual compulsivity."

Since Prause has flip-flopped, where is Ley's support for the "porn/sex addiction = high libido" claim? Below are multiple studies that tested, and falsified, David Ley's "high libido = sex/porn addiction" claim entirely:

1) "Is High Sexual Desire a Facet of Male Hypersexuality? Results from an Online Study." (2015) - Researchers found virtually no overlap between the men with hypersexuality and the men with "High Sexual Desire". Excerpt from the paper:

"The study findings point to a distinct phenomenology of High Sexual Desire and Hypersexuality in men."

2) "Hypersexuality and High Sexual Desire: Exploring the Structure of Problematic Sexuality" (2015) - The study found little overlap between high sexual desire and hypersexuality. Excerpt from the paper:

"Our study supports the distinctiveness of hypersexuality and high sexual desire/activity."

3) "Neural Correlates of Sexual Cue Reactivity in Individuals with and without Compulsive Sexual Behaviours" (2014) - A Cambridge University fMRI study comparing porn addicts to healthy controls. The study found that porn addicts had lower sexual desire and greater difficulty achieving erections, yet had greater cue-reactivity to porn (similar to Steele et al. above). Excerpts from the paper:

"On an adapted version of the Arizona Sexual Experiences Scale [43], CSB subjects compared to healthy volunteers had significantly more difficulty with sexual arousal and experienced more erectile difficulties in intimate sexual relationships but not to sexually explicit material (Table S3 in File S1)."

CSB subjects reported that as a result of excessive use of sexually explicit materials..... experienced diminished libido or erectile function specifically in physical relationships with women (although not in relationship to the sexually explicit material)...

4) “Patient Characteristics by Type of Hypersexuality Referral: A Quantitative Chart Review of 115 Consecutive Male Cases" (2015) – Study on men with hypersexuality disorders. 27 were classified as “avoidant masturbators,” meaning they masturbated to porn one or more hours per day or more than 7 hours per week. 71% of the compulsive porn users reported sexual functioning problems, with 33% reporting delayed ejaculation.

5) "Erectile Dysfunction, Boredom, and Hypersexuality among Coupled Men from Two European Countries" (2015) - This survey reported a strong correlation between erectile dysfunction and measures of hypersexuality. Excerpt:

"Hypersexuality was significantly correlated with proneness to sexual boredom and more problems with erectile function."

6) “Adolescents and web porn: a new era of sexuality (2015)” – This Italian study analyzed the effects of Internet porn on high school seniors, co-authored by urology professor Carlo Foresta, president of the Italian Society of Reproductive Pathophysiology. The most interesting finding is that 16% of those who consume porn more than once a week report abnormally low sexual desire compared with 0% in non-consumers (and 6% for those who consume less than once a week). From the study:

"21.9% define it as habitual, 10% report that it reduces sexual interest towards potential real-life partners, and the remaining, 9.1% report a kind of addiction. In addition, 19% of overall pornography consumers report an abnormal sexual response, while the percentage rose to 25.1% among regular consumers."

7) "Brain Structure and Functional Connectivity Associated With Pornography Consumption: The Brain on Porn" (2014) - A Max Planck study which found 3 significant addiction-related brain changes correlating with the amount of porn consumed. It also found that the more porn consumed the less reward circuit activity in response to brief exposure (.530 second) to vanilla porn. In a 2014 article lead author Simone Kühn said:

"We assume that subjects with a high porn consumption need increasing stimulation to receive the same amount of reward. That could mean that regular consumption of pornography more or less wears out your reward system. That would fit perfectly the hypothesis that their reward systems need growing stimulation."

A more technical description of this study from a review of the literature by Kuhn & Gallinat - Neurobiological Basis of Hypersexuality (2016).

"The more hours participants reported consuming pornography, the smaller the BOLD response in left putamen in response to sexual images. Moreover, we found that more hours spent watching pornography was associated with smaller gray matter volume in the striatum, more precisely in the right caudate reaching into the ventral putamen. We speculate that the brain structural volume deficit may reflect the results of tolerance after desensitization to sexual stimuli."

8) "Unusual masturbatory practice as an etiological factor in the diagnosis and treatment of sexual dysfunction in young men" (2014) - One of the 4 case studies in this paper reports on a man with porn-induced sexual problems (low libido, fetishes, anorgasmia). The sexual intervention called for a 6-week abstinence from porn and masturbation. After 8 months the man reported increased sexual desire, successful sex and orgasm, and enjoying "good sexual practices."

9) "Pornography use: who uses it and how it is associated with couple outcomes" (2012) - While not a study on "hypersexuals", it reported that 1) porn use was consistently correlated with low scores on sexual satisfaction, and 2) that there was no differences in sexual desire between the porn users and the non-users.

10) Sexual Desire, not Hypersexuality, is Related to Neurophysiological Responses Elicited by Sexual Images (2013) - This EEG study was touted in the media as evidence against the existence of porn/sex addiction. Not so. This SPAN Lab study, like #11 below, actually lends support to the existence of both porn addiction and porn use down-regulating sexual desire. How so? The study reported higher EEG readings (relative to neutral pictures) when subjects were briefly exposed to pornographic photos. Studies consistently show that an elevated P300 occurs when addicts are exposed to cues (such as images) related to their addiction. However, due to methodological flaws the findings are uninterpretable: 1) the study had no control group for comparison; 2) subjects were heterogeneous (males, females, non-heterosexuals); 3) subjects were not screened for mental disorders or addictions; 4) the questionnaires were not validated for porn addiction. In line with the Cambridge University brain scan studies, this EEG study also reported greater cue-reactivity to porn correlating with less desire for partnered sex. To put another way - individuals with greater brain activation to porn would rather masturbate to porn than have sex with a real person. Shockingly, study spokesperson Nicole Prause claimed that porn users merely had "high libido", yet the results of the study say the exact opposite (their desire for partnered sex was dropping in relation to their porn use). Five peer-reviewed papers expose the truth: 1, 2, 3, 4, 5. Also see the extensive YBOP critique.

11) Modulation of Late Positive Potentials by Sexual Images in Problem Users and Controls Inconsistent with "Porn Addiction" (2015) - Another SPAN Lab EEG (brain-wave) study comparing the 2013 subjects from the above study to an actual control group (yet it suffered from the same methodological flaws named above). The results: compared to controls "individuals experiencing problems regulating their porn viewing" had lower brain responses to one-second exposure to photos of vanilla porn. The lead author, Nicole Prause, claims these results "debunk porn addiction". What legitimate scientist would claim that their lone anomalous study has debunked an entire field of study? In reality, the findings of Prause et al. 2015 align perfectly with Kühn & Gallinat (2014), which found that more porn use correlated with less brain activation in response to pictures of vanilla porn. Prause's findings also align with Banca et al. 2015 which is #4 in this list. Moreover, another EEG study found that greater porn use in women correlated with less brain activation to porn. Lower EEG readings mean that subjects are paying less attention to the pictures. Put simply, frequent porn users were desensitized to static images of vanilla porn. They were bored (habituated or desensitized). See this extensive YBOP critique. Six peer-reviewed papers agree that this study actually found desensitization/habituation in frequent porn users (a sign of addiction): 1, 2, 3, 4, 5, 6.

12) Use of pornography in a random sample of Norwegian heterosexual couples (2009) - Porn use was correlated with more sexual dysfunctions in the man and negative self perception in the female. The couples who did not use porn had no sexual dysfunctions. A few excerpts from the study:

In couples where only one partner used pornography, we found more problems related to arousal (male) and negative (female) self-perception.

The couples who did not use pornography... may be considered more traditional in relation to the theory of sexual scripts. At the same time, they did not seem to have any dysfunctions.

13) Masturbation and Pornography Use Among Coupled Heterosexual Men With Decreased Sexual Desire: How Many Roles of Masturbation? (2015) - Masturbating to porn was related with decreased sexual desire and low relationship intimacy. Excerpts:

"Among men who masturbated frequently, 70% used pornography at least once a week. A multivariate assessment showed that sexual boredom, frequent pornography use, and low relationship intimacy significantly increased the odds of reporting frequent masturbation among coupled men with decreased sexual desire."

"Among men [with decreased sexual desire] who used pornography at least once a week [in 2011], 26.1% reported that they were unable to control their pornography use. In addition, 26.7% of men reported that their use of pornography negatively affected their partnered sex and 21.1% claimed to have attempted to stop using pornography."

14) Men's Sexual Life and Repeated Exposure to Pornography. A New Issue? (2015) - Excerpts:

Mental health specialists should take in consideration the possible effects of pornography consumption on men sexual behaviors, men sexual difficulties and other attitudes related to sexuality. In the long term pornography seems to create sexual dysfunctions, especially the individual’s inability to reach an orgasm with his partner. Someone who spends most of his sexual life masturbating while watching porn engages his brain in rewiring its natural sexual sets so that it will soon need visual stimulation to achieve an orgasm.

Many different symptoms of porn consumption, such as the need to involve a partner in watching porn, the difficulty in reaching orgasm, the need for porn images in order to ejaculate turn into sexual problems. These sexual behaviors may go on for months or years and it may be mentally and bodily associated with the erectile dysfunction, although it is not an organic dysfunction. Because of this confusion, which generates embarrassment, shame and denial, lots of men refuse to encounter a specialist

Pornography offers a very simple alternative to obtain pleasure without implying other factors that were involved in human’s sexuality along the history of mankind. The brain develops an alternative path for sexuality which excludes “the other real person” from the equation. Furthermore, pornography consumption in a long term makes men more prone to difficulties in obtaining an erection in a presence of their partners.

15) Understanding the Personality and Behavioral Mechanisms Defining Hypersexuality in Men Who Have Sex With Men (2016)

Further, we found no associations between the CSBI Control scale and the BIS-BAS. This would indicate that lack of sexual behavior control is related to specific sexual excitation and inhibitory mechanisms and not to more general behavioral activation and inhibitory mechanisms. This would seem to support conceptualizing hypersexuality as a dysfunction of sexuality as proposed by Kafka. Further, it does not appear that hypersexuality is a manifestation of high sex drive, but that it involves high excitation and a lack of inhibitory control, at least with respect to inhibition owing to expected negative outcomes.

16) Hypersexual, Sexually Compulsive, or Just Highly Sexually Active? Investigating Three Distinct Groups of Gay and Bisexual Men and Their Profiles of HIV-Related Sexual Risk (2016) - If high sexual desire and sex addiction were the same, there would only be one group of individuals per population. This study, like the ones above, reported several distinct sub-groups, yet all groups reported similar rates of sexual activity.  

Emerging research supports the notion that sexual compulsivity (SC) and hypersexual disorder (HD) among gay and bisexual men (GBM) might be conceptualized as comprising three groups—Neither SC nor HD; SC only, and Both SC and HD—that capture distinct levels of severity across the SC/HD continuum.

Nearly half (48.9 %) of this highly sexually active sample was classified as Neither SC nor HD, 30 % as SC Only, and 21.1 % as Both SC and HD. While we found no significant differences between the three groups on reported number of male partners, anal sex acts, or anal sex acts

17) The effects of sexually explicit material use on romantic relationship dynamics (2016) - As with many other studies, solitary porn users report poorer relationship and sexual satisfaction. Employing the Pornography Consumption Effect Scale (PCES), the study found that higher porn use was related to poorer sexual function, more sexual problems, and a "worse sex life". An excerpt describing the correlation between the PCES "Negative Effects" on "Sex Life" questions and frequency of porn use:

There were no significant differences for the Negative Effect Dimension PCES across the frequency of sexually explicit material use; however, there were significant differences on the Sex Life subscale where High Frequency Porn Users reported greater negative effects than Low Frequency Porn Users.

18) Male masturbation habits and sexual dysfunctions (2016) - It's by a French psychiatrist who is the current president of the European Federation of Sexology. While the abstract shifts back and forth between Internet pornography use and masturbation, it's clear that he's mostly referring to porn-induced sexual dysfunctions (erectile dysfunction and anorgasmia). The paper revolves around his clinical experience with 35 men who developed erectile dysfunction and/or anorgasmia, and his therapeutic approaches to help them. The author states that most of his patients used porn, with several being addicted to porn. The abstract points to internet porn as the primary cause of the problems (keep in mind that masturbation does not cause chronic ED, and it is never given as a cause of ED). Excerpts:

Intro: Harmless and even helpful in his usual form widely practiced, masturbation in its excessive and pre-eminent form, generally associated today to pornographic addiction, is too often overlooked in the clinical assessment of sexual dysfunction it can induce.

Results: Initial results for these patients, after treatment to “unlearn” their masturbatory habits and their often associated addiction to pornography, are encouraging and promising. A reduction in symptoms was obtained in 19 patients out of 35. The dysfunctions regressed and these patients were able to enjoy satisfactory sexual activity.

Conclusion: Addictive masturbation, often accompanied by a dependency on cyber-pornography, has been seen to play a role in the etiology of certain types of erectile dysfunction or coital anejaculation. It is important to systematically identify the presence of these habits rather than conduct a diagnosis by elimination, in order to include habit-breaking deconditioning techniques in managing these dysfunctions.

19) The Dual Control Model - The Role Of Sexual Inhibition & Excitation In Sexual Arousal And Behavior (2007) - Newly rediscovered and very convincing. In an experiment employing video porn, 50% of the young men couldn't become aroused or achieve erections with porn (average age was 29). The shocked researchers discovered that the men's erectile dysfunction was,

"related to high levels of exposure to and experience with sexually explicit materials."

The men experiencing erectile dysfunction had spent a considerable amount of time in bars and bathhouses where porn was "omnipresent," and "continuously playing". The researchers stated:

"Conversations with the subjects reinforced our idea that in some of them a high exposure to erotica seemed to have resulted in a lower responsivity to "vanilla sex" erotica and an increased need for novelty and variation, in some cases combined with a need for very specific types of stimuli in order to get aroused."

20) Online sexual activities: An exploratory study of problematic and non-problematic usage patterns in a sample of men (2016) - This Belgian study from a leading research university found problematic Internet porn use was associated with reduced erectile function and reduced overall sexual satisfaction. Yet problematic porn users experienced greater cravings. The study appears to report escalation, as 49% of the men viewed porn that "was not previously interesting to them or that they considered disgusting." (See studies reporting habituation/desensitization to porn and escalation of porn use) Excerpts:

"This study is the first to directly investigate the relationships between sexual dysfunctions and problematic involvement in OSAs. Results indicated that higher sexual desire, lower overall sexual satisfaction, and lower erectile function were associated with problematic OSAs (online sexual activities). These results can be linked to those of previous studies reporting a high level of arousability in association with sexual addiction symptoms (Bancroft & Vukadinovic, 2004; Laier et al., 2013; Muise et al., 2013)."

In addition, we finally have a study that asks porn users about possible escalation to new or disturbing porn genres. Guess what it found?

"Forty-nine percent mentioned at least sometimes searching for sexual content or being involved in OSAs that were not previously interesting to them or that they considered disgusting, and 61.7% reported that at least sometimes OSAs were associated with shame or guilty feelings."

Note - This is the first study to directly investigate the relationships between sexual dysfunctions and problematic porn use. Two other studies claiming to have investigated correlations between porn use and erectile functioning cobbled together data from earlier studies in an unsuccessful attempt to debunk porn-induced ED. Both were criticized in the peer-reviewed literature: paper 1 was not an authentic study, and has been thoroughly discredited; paper 2 actually found correlations that support porn-induced ED. Moreover, paper 2 was only a "brief communication" that did not report important data.

21) Altered Appetitive Conditioning and Neural Connectivity in Subjects With Compulsive Sexual Behavior (2016) - "Compulsive Sexual Behaviors" (CSB) means the men were porn addicts, because CSB subjects averaged nearly 20 hours of porn use per week. The controls averaged 29 minutes per week. Interestingly, 3 of the 20 CSB subjects mentioned to interviewers that they suffered from "orgasmic-erection disorder," while none of the control subjects reported sexual problems.

22) Study sees link between porn and sexual dysfunction (2017) - The findings of an upcoming study presented at the American Urological Association's annual meeting. A few excerpts:

Young men who prefer pornography to real-world sexual encounters might find themselves caught in a trap, unable to perform sexually with other people when the opportunity presents itself, a new study reports. Porn-addicted men are more likely to suffer from erectile dysfunction and are less likely to be satisfied with sexual intercourse, according to survey findings presented Friday at the American Urological Association's annual meeting, in Boston.

23) “I think it has been a negative influence in many ways but at the same time I can’t stop using it”: Self-identified problematic pornography use among a sample of young Australians (2017) - Online survey of Australians, aged 15-29.  Those who had ever viewed pornography (n=856) were asked in an open-ended question: ‘How has pornography influenced your life?’.

Among participants who responded to the open-ended question (n=718), problematic usage was self-identified by 88 respondents. Male participants who reported problematic usage of pornography highlighted effects in three areas: on sexual function, arousal and relationships. Responses included “I think it has been a negative influence in many ways but at the same time I can’t stop using it” (Male, Aged 18–19).

24) Exploring the Relationship Between Erotic Disruption During the Latency Period and the Use of Sexually Explicit Material, Online Sexual Behaviors, and Sexual Dysfunctions in Young Adulthood (2009) - Study examined correlations between current porn use (sexually explicit material - SEM) and sexual dysfunctions, and porn use during "latency period" (ages 6-12) and sexual dysfunctions. The average age of participants was 22. While current porn use correlated with sexual dysfunctions, porn use during latency (ages 6-12) had an even stronger correlation with sexual dysfunctions. A few excerpts:

Findings suggested that latency erotic disruption by way of sexually explicit material (SEM) and/or child sexual abuse may be associated to adult online sexual behaviors.

Furthermore, results demonstrated that latency SEM exposure was a significant predictor of adult sexual dysfunctions.

We hypothesized that exposure to latency SEM exposure would predict adult use of SEM. Study findings supported our hypothesis, and demonstrated that latency SEM exposure was a statistically significant predictor of adult SEM use. This suggested that individuals who were exposed to SEM during latency, may continue this behavior into adulthood. Study findings also indicated that latency SEM exposure was a significant predictor of adult online sexual behaviors.

In short, the evidence is piling up that internet porn erodes normal sexual desire, leaving users less responsive to pleasure. They may crave porn, but that is more likely evidence of an addiction-related brain change known as "sensitization" (hyper-reactivity to addiction-related cues). Cravings certainly cannot be assumed to be evidence of greater libido.


LEY: "It is most likely that these dispositions correlate with neurological characteristics, which these studies are finding. In other words, these neurological characteristics are in fact the cause, not the effect."

RESPONSE: Without a shred of evidence or a single example, Ley is claiming that the brain changes found the 32 studies addiction must have existed before porn use. In reality, the two main addiction-related brain changes reported by the studies can only develop from chronic use:

  1. Sensitization: Chronic use leads to altered nerve connections which cause the reward circuitry to buzz in response to addiction-related cues or thoughts. This Pavlovian memory is what induces severe cravings that make the addiction far more compelling than other activities in the addict's life. (Studies reporting sensitization in internet porn users: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.)
  2. Desensitization: Chronic use leads to the individual becoming less sensitive to pleasure, which often manifests as the need for greater and greater stimulation to achieve the same buzz. This is referred to as tolerance and only occurs with chronic use. (Studies reporting desensitization in porn users: : 1, 2, 3, 4, 5, 6.)

It's quite telling that Ley is incapable of naming these "neurological characteristics." Reality: The mechanisms of addiction have been studied for nearly 60 years. The very specific brain changes caused by addiction have been elucidated down to the cellular, protein, and epigenetic levels. These brain changes have been correlated over and over with the behaviors collectively known as the "addiction phenotype." Addiction-like behaviors can be induced in animals simply by increasing a single protein within the reward center (Deltafosb). In short, a lot is known about the biology of addiction - more than any other mental disorder - even if it remains unknown to Dr. Ley.

Four major brain changes are involved with both drug and behavioral addictions, as outlined in this paper published this year in The New England Journal of Medicine: "Neurobiologic Advances from the Brain Disease Model of Addiction (2016)". This landmark review by the Director of the National Institute on Alcohol Abuse and Alcoholism (NIAAA) George F. Koob, and the director of the National Institute on Drug Abuse (NIDA) Nora D. Volkow, not only outlines the brain changes involved in addiction, it also states in its opening paragraph that sex addiction exists:

"We conclude that neuroscience continues to support the brain disease model of addiction. Neuroscience research in this area not only offers new opportunities for the prevention and treatment of substance addictions and related behavioral addictions (e.g., to food, sex, and gambling)...."

In simple, and very broad, terms the major fundamental brain changes are: 1) Sensitization, 2) Desensitization, 3) Hypofrontality/Dysfunctional prefrontal circuits 4) Dysfunctional stress circuits. All 4 of these brain changes have been identified among the 23 neuroscience studies on porn users:

  1. Studies reporting sensitization in porn users: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.
  2. Studies reporting desensitization in porn users: 1, 2, 3, 4, 5, 6.
  3. Studies reporting "hypofrontality" in porn users: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13.
  4. Studies reporting dysfunctional stress responses in porn users: 1, 2, 3.

I find it interesting that Dr. Ley seems to always claim that there's no scientific support for porn addiction, yet not only do 37 studies provide support for porn/sex addiction, the world's top addiction experts do also. The little bubble he has constructed, where porn addiction cannot possibly exist, is seriously out of step with science.


LEY: "Grubbs also found recently that the identity of “porn addict” is an iatrogenic concept, which creates harm and distress, by telling an individual to hate and fear their own sexuality"

RESPONSE: Nothing could farther from the truth. Here is an extensive analysis of Grubbs's study - Critique of "Perceived Addiction to Internet Pornography and Psychological Distress: Examining Relationships Concurrently and Over Time" (2015).

Both Ley's and the Grubbs study's claims depend upon two false premises:

  1. That Grubbs's porn addiction test (CPUI) assesses "perceived porn addiction" rather than actual addiction. It does not. Grubbs et al. re-labeled Grubbs's self-created porn addiction test as a "perceived porn addiction" test. However, this Cyber Pornography Use Inventory (CPUI) questionnaire is in fact similar to many other drug and behavioral addiction questionnaires. Like other addiction tests, the CPUI assesses behaviors and symptoms common to all addictions, such as: the inability to control use; compulsion to use, cravings to use, negative psychological, social and emotional effects; and preoccupation with using. In fact, only 1 of its 9 questions even hints at "perceived addiction." Yet we are told that a person's total score for all 9 questions is synonymous with "perceived addiction" rather than addiction itself. Very misleading, very clever, and without any scientific basis.
  2. That Grubbs found little correlation between CPUI scores and hours of porn use. Contrary to Ley's claim, Grubbs found a pretty strong correlation between hours of use and the CPUI! From p. 6 of the study:

"Additionally, average daily pornography use in hours was significantly and positively associated with depression, anxiety, and anger, as well as with perceived addiction."

Stop the presses! This excerpt directly contradicts all the headlines, which claim that pornography use was NOT strongly correlated with psychological distress or "perceived addiction." Again, whenever you see the phrase "perceived addiction" it actually denotes the subjects' total score on the CPUI (which is a porn addiction test). Really get this: The Grubbs study did NOT assess "perceived addiction." There are many more details in this critique that debunks assertions put forth in lay articles and the claims made within the Grubbs's studies: Is Joshua Grubbs pulling the wool over our eyes with his "perceived porn addiction" research? (2016)


LEY: "There has not been a single peer-reviewed paper published which demonstrate any evidence that ED related to porn use is a real phenomenon."

RESPONSE: Absoluely false. And it's not just erectile dysfunction. Several studies have found relationships between porn use in young men and ED, anorgamsia, low sexual desire, delayed ejaculation and lower brain activation to sexual images. In addition this page contains articles and videos by over 100 experts (urology professors, urologists, psychiatrists, psychologists, sexologists, MDs) who acknowledge and have successfully treated porn-induced ED and porn-induced loss of sexual desire.

Studies reporting links between porn use/sex addiction and ED, anorgamsia, low sexual desire, delayed ejaculation, and lower brain activation to sexual images.

The first 5 studies demonstrate causation as participants eliminated porn use and healed chronic sexual dysfunctions:

1) Is Internet Pornography Causing Sexual Dysfunctions? A Review with Clinical Reports (2016) - An extensive review of the literature related to porn-induced sexual problems. Involving US Navy doctors, the review provides the latest data revealing a tremendous rise in youthful sexual problems. It also reviews the neurological studies related to porn addiction and sexual conditioning via Internet porn. The doctors provide 3 clinical reports of men who developed porn-induced sexual dysfunctions. Two of the three men healed their sexual dysfunctions by eliminating porn use. The third man experienced little improvement as he was unable to abstain from porn use. Excerpt:

Traditional factors that once explained men’s sexual difficulties appear insufficient to account for the sharp rise in erectile dysfunction, delayed ejaculation, decreased sexual satisfaction, and diminished libido during partnered sex in men under 40. This review (1) considers data from multiple domains, e.g., clinical, biological (addiction/urology), psychological (sexual conditioning), sociological; and (2) presents a series of clinical reports, all with the aim of proposing a possible direction for future research of this phenomenon. Alterations to the brain's motivational system are explored as a possible etiology underlying pornography-related sexual dysfunctions. This review also considers evidence that Internet pornography’s unique properties (limitless novelty, potential for easy escalation to more extreme material, video format, etc.) may be potent enough to condition sexual arousal to aspects of Internet pornography use that do not readily transition to real-life partners, such that sex with desired partners may not register as meeting expectations and arousal declines. Clinical reports suggest that terminating Internet pornography use is sometimes sufficient to reverse negative effects, underscoring the need for extensive investigation using methodologies that have subjects remove the variable of Internet pornography use.

2) Male masturbation habits and sexual dysfunctions (2016) - It's by a French psychiatrist who is the current president of the European Federation of Sexology. While the abstract shifts back and forth between Internet pornography use and masturbation, it's clear that he's mostly referring to porn-induced sexual dysfunctions (erectile dysfunction and anorgasmia). The paper revolves around his clinical experience with 35 men who developed erectile dysfunction and/or anorgasmia, and his therapeutic approaches to help them. The author states that most of his patients used porn, with several being addicted to porn. The abstract points to internet porn as the primary cause of the problems (keep in mind that masturbation does not cause chronic ED, and it is never given as a cause of ED). Excerpts:

Intro: Harmless and even helpful in his usual form widely practiced, masturbation in its excessive and pre-eminent form, generally associated today to pornographic addiction, is too often overlooked in the clinical assessment of sexual dysfunction it can induce.

Results: Initial results for these patients, after treatment to “unlearn” their masturbatory habits and their often associated addiction to pornography, are encouraging and promising. A reduction in symptoms was obtained in 19 patients out of 35. The dysfunctions regressed and these patients were able to enjoy satisfactory sexual activity.

Conclusion: Addictive masturbation, often accompanied by a dependency on cyber-pornography, has been seen to play a role in the etiology of certain types of erectile dysfunction or coital anejaculation. It is important to systematically identify the presence of these habits rather than conduct a diagnosis by elimination, in order to include habit-breaking deconditioning techniques in managing these dysfunctions.

3) Unusual masturbatory practice as an etiological factor in the diagnosis and treatment of sexual dysfunction in young men (2014) – One of the 4 case studies in this paper reports on a man with porn-induced sexual problems (low libido, fetishes, anorgasmia). The sexual intervention called for a 6-week abstinence from porn and masturbation. After 8 months the man reported increased sexual desire, successful sex and orgasm, and enjoying “good sexual practices. This is the first peer-reviewed chronicling of a recovery from porn-induced sexual dysfunctions. Excerpts from the paper:

"When asked about masturbatory practices, he reported that in the past he had been masturbating vigorously and rapidly while watching pornography since adolescence. The pornography originally consisted mainly of zoophilia, and bondage, domination, sadism, and masochism, but he eventually got habituated to these materials and needed more hardcore pornography scenes, including transgender sex, orgies, and violent sex. He used to buy illegal pornographic movies on violent sex acts and rape and visualized those scenes in his imagination to function sexually with women. He gradually lost his desire and his ability to fantasize and decreased his masturbation frequency."

In conjunction with weekly sessions with a sex therapist, the patient was instructed to avoid any exposure to sexually explicit material, including videos, newspapers, books, and internet pornography.

After 8 months, the patient reported experiencing successful orgasm and ejaculation. He renewed his relationship with that woman, and they gradually succeeded in enjoying good sexual practices.

4) How difficult is it to treat delayed ejaculation within a short-term psychosexual model? A case study comparison (2017) - A report on two "composite cases" illustrating the causes and treatments for delayed ejaculation (anorgasmia). "Patient B" represented several young men treated by the therapist. Interestingly, the paper states that Patient B's "porn use had escalated into harder material", "as is often the case". The paper says that porn-related delayed ejaculation is not uncommon, and on the rise. The author calls for more research on porn's effects of sexual functioning. Patient B's delayed ejaculation was healed after 10 weeks of no porn. Excerpts:

The cases are composite cases taken from my work within the National Health Service in Croydon University Hospital, London. With the latter case (Patient B), it is important to note that the presentation reflects a number of young males who have been referred by their GPs with a similar diagnosis. Patient B is a 19-year-old who presented because he was unable to ejaculate via penetration. When he was 13, he was regularly accessing pornography sites either on his own through internet searches or via links that his friends sent him. He began masturbating every night while searching his phone for image…If he did not masturbate he was unable to sleep. The pornography he was using had escalated, as is often the case (see Hudson-Allez, 2010), into harder material (nothing illegal)…

Patient B was exposed to sexual imagery via pornography from the age of 12 and the pornography he was using had escalated to bondage and dominance by the age of 15.

We agreed that he would no longer use pornography to masturbate. This meant leaving his phone in a different room at night. We agreed that he would masturbate in a different way….

Patient B was able to achieve orgasm via penetration by the fifth session; the sessions are offered fortnightly in Croydon University Hospital so session five equates to approximately 10 weeks from consultation. He was happy and greatly relieved. In a three-month follow-up with Patient B, things were still going well.

Patient B is not an isolated case within the National Health Service (NHS) and in fact young men in general accessing psychosexual therapy, without their partners, speaks in itself to the stirrings of change.

This article therefore supports previous research that has linked masturbation style to sexual dysfunction and pornography to masturbation style. The article concludes by suggesting that the successes of psychosexual therapists in working with DE are rarely recorded in the academic literature, which has allowed the view of DE as a difficult disorder to treat remain largely unchallenged. The article calls for research into pornography usage and its effect on masturbation and genital desensitisation.

5) Situational Psychogenic Anejaculation: A Case Study (2014) - The details reveal a case of porn-induced anejaculation. The husband's only sexual experience prior to marriage was frequent masturbation to pornography - where he was able to ejaculate. He also reported sexual intercourse as less arousing than masturbation to porn. The key piece of information is that "re-training" and psychotherapy failed to heal his anejaculation. When those interventions failed, therapists suggested a complete ban on masturbation to porn. Eventually this ban resulted in successful sexual intercourse and ejaculation with a partner for the first time in his life. A few excerpts:

A is a 33-year-old married male with heterosexual orientation, a professional from a middle socio-economic urban background. He has had no premarital sexual contacts. He watched pornography and masturbated frequently. His knowledge about sex and sexuality was adequate. Following his marriage, Mr. A described his libido as initially normal, but later reduced secondary to his ejaculatory difficulties. Despite thrusting movements for 30-45 minutes, he had never been able to ejaculate or achieve orgasm during penetrative sex with his wife.

What didn't work:

Mr. A's medications were rationalized; clomipramine and bupropion were discontinued, and sertraline was maintained at a dose of 150 mg per day. Therapy sessions with the couple were held weekly for the initial few months, following which they were spaced to fortnightly and later monthly. Specific suggestions including focusing on sexual sensations and concentrating on the sexual experience rather than ejaculation were used to help reduce performance anxiety and spectatoring. Since problems persisted despite these interventions, intensive sex therapy was considered.

Eventually they instituted a complete ban on masturbation (which means he continued to masturbate to porn during the above failed interventions):

A ban on any form of sexual activity was suggested. Progressive sensate focus exercises (initially non-genital and later genital) were initiated. Mr. A described an inability to experience the same degree of stimulation during penetrative sex as compared to that which he experienced during masturbation. Once the ban on masturbation was enforced, he reported an increased desire for sexual activity with his partner.

After an unspecified amount of time, the ban on masturbation to porn lead to success:

Meanwhile, Mr. A and his wife decided to go ahead with Assisted Reproductive Techniques (ART) and underwent two cycles of intrauterine insemination. During a practice session, Mr. A ejaculated for the first time, following which he has been able to ejaculate satisfactorily during a majority of the couple's sexual interactions.

 

6) The Dual Control Model - The Role Of Sexual Inhibition & Excitation In Sexual Arousal And Behavior (2007) - Newly rediscovered and very convincing. In an experiment employing video porn, 50% of the young men couldn't become aroused or achieve erections with porn (average age was 29). The shocked researchers discovered that the men's erectile dysfunction was,

"related to high levels of exposure to and experience with sexually explicit materials."

The men experiencing erectile dysfunction had spent a considerable amount of time in bars and bathhouses where porn was "omnipresent," and "continuously playing". The researchers stated:

"Conversations with the subjects reinforced our idea that in some of them a high exposure to erotica seemed to have resulted in a lower responsivity to "vanilla sex" erotica and an increased need for novelty and variation, in some cases combined with a need for very specific types of stimuli in order to get aroused."

7) Neural Correlates of Sexual Cue Reactivity in Individuals with and without Compulsive Sexual Behaviours (2014) - This fMRI study by Cambridge University found sensitization in porn addicts which mirrored sensitization in drug addicts. It also found that porn addicts fit the accepted addiction model of wanting "it" more, but not liking "it" more. The researchers also reported that 60% of subjects (average age: 25) had difficulty achieving erections/arousal with real partners as a result of using porn, yet could achieve erections with porn. From the study (CSB is compulsive sexual behaviours):

"CSB subjects reported that as a result of excessive use of sexually explicit materials.....[they] experienced diminished libido or erectile function specifically in physical relationships with women (although not in relationship to the sexually explicit material)"

"Compared to healthy volunteers, CSB subjects had greater subjective sexual desire or wanting to explicit cues and had greater liking scores to erotic cues, thus demonstrating a dissociation between wanting and liking. CSB subjects also had greater impairments of sexual arousal and erectile difficulties in intimate relationships but not with sexually explicit materials highlighting that the enhanced desire scores were specific to the explicit cues and not generalized heightened sexual desire."

8) Online sexual activities: An exploratory study of problematic and non-problematic usage patterns in a sample of men (2016) - This Belgian study from a leading research university found problematic Internet porn use was associated with reduced erectile function and reduced overall sexual satisfaction. Yet problematic porn users experienced greater cravings. The study appears to report escalation, as 49% of the men viewed porn that "was not previously interesting to them or that they considered disgusting." (See studies reporting habituation/desensitization to porn and escalation of porn use) Excerpts:

"This study is the first to directly investigate the relationships between sexual dysfunctions and problematic involvement in OSAs. Results indicated that higher sexual desire, lower overall sexual satisfaction, and lower erectile function were associated with problematic OSAs (online sexual activities). These results can be linked to those of previous studies reporting a high level of arousability in association with sexual addiction symptoms (Bancroft & Vukadinovic, 2004; Laier et al., 2013; Muise et al., 2013)."

In addition, we finally have a study that asks porn users about possible escalation to new or disturbing porn genres. Guess what it found?

"Forty-nine percent mentioned at least sometimes searching for sexual content or being involved in OSAs that were not previously interesting to them or that they considered disgusting, and 61.7% reported that at least sometimes OSAs were associated with shame or guilty feelings."

9) Adolescents and web porn: a new era of sexuality (2015) - This Italian study analyzed the effects of Internet porn on high school seniors, co-authored by urology professor Carlo Foresta, president of the Italian Society of Reproductive Pathophysiology. The most interesting finding is that 16% of those who consume porn more than once a week report abnormally low sexual desire compared with 0% in non-consumers (and 6% for those who consume less than once a week). From the study:

"21.9% define it as habitual, 10% report that it reduces sexual interest towards potential real-life partners, and the remaining, 9.1% report a kind of addiction. In addition, 19% of overall pornography consumers report an abnormal sexual response, while the percentage rose to 25.1% among regular consumers."

10) Patient Characteristics by Type of Hypersexuality Referral: A Quantitative Chart Review of 115 Consecutive Male Cases (2015) - Study on men (average age 41.5) with hypersexuality disorders, such as paraphilias and chronic masturbation or adultery. 27 were classified as "avoidant masturbators," meaning they masturbated (typically with porn use) one or more hours per day or more than 7 hours per week. 71% reported sexual functioning problems, with 33% reporting delayed ejaculation (a precursor to porn-induced ED). What sexual dysfunction do 38% of the remaining men have? The study doesn't say, and the authors have ignored requests for details. Two primary choices for male sexual dysfunction are ED and low libido. The men were not asked about their erectile functioning without porn. If all their sexual activity involved masturbating to porn, and not sex with a partner, they might never realize they had porn-induced ED.

11) The effects of sexually explicit material use on romantic relationship dynamics (2016) - As with many other studies, solitary porn users report poorer relationship and sexual satisfaction. Employing the Pornography Consumption Effect Scale (PCES), the study found that higher porn use was related to poorer sexual function, more sexual problems, and a "worse sex life". An excerpt describing the correlation between the PCES "Negative Effects" on "Sex Life" questions and frequency of porn use:

There were no significant differences for the Negative Effect Dimension PCES across the frequency of sexually explicit material use; however, there were significant differences on the Sex Life subscale where High Frequency Porn Users reported greater negative effects than Low Frequency Porn Users.

12) Altered Appetitive Conditioning and Neural Connectivity in Subjects With Compulsive Sexual Behavior (2016) - "Compulsive Sexual Behaviors" (CSB) means the men were porn addicts, because CSB subjects averaged nearly 20 hours of porn use per week. The controls averaged 29 minutes per week. Interestingly, 3 of the 20 CSB subjects mentioned to interviewers that they suffered from "orgasmic-erection disorder," while none of the control subjects reported sexual problems.

13) Men's Sexual Life and Repeated Exposure to Pornography. A New Issue? (2015) - Excerpts:

Mental health specialists should take in consideration the possible effects of pornography consumption on men sexual behaviors, men sexual difficulties and other attitudes related to sexuality. In the long term pornography seems to create sexual dysfunctions, especially the individual’s inability to reach an orgasm with his partner. Someone who spends most of his sexual life masturbating while watching porn engages his brain in rewiring its natural sexual sets (Doidge, 2007) so that it will soon need visual stimulation to achieve an orgasm.

Many different symptoms of porn consumption, such as the need to involve a partner in watching porn, the difficulty in reaching orgasm, the need for porn images in order to ejaculate turn into sexual problems. These sexual behaviors may go on for months or years and it may be mentally and bodily associated with the erectile dysfunction, although it is not an organic dysfunction. Because of this confusion, which generates embarrassment, shame and denial, lots of men refuse to encounter a specialist

Pornography offers a very simple alternative to obtain pleasure without implying other factors that were involved in human’s sexuality along the history of mankind. The brain develops an alternative path for sexuality which excludes “the other real person” from the equation. Furthermore, pornography consumption in a long term makes men more prone to difficulties in obtaining an erection in a presence of their partners.

14) Brain Structure and Functional Connectivity Associated With Pornography Consumption: The Brain on Porn (2014) - A Max Planck study which found 3 significant addiction-related brain changes correlating with the amount of porn consumed. It also found that the more porn consumed the less reward circuit activity in response to brief exposure (.530 second) to vanilla porn. In a 2014 article lead author Simone Kühn said:

"We assume that subjects with a high porn consumption need increasing stimulation to receive the same amount of reward. That could mean that regular consumption of pornography more or less wears out your reward system. That would fit perfectly the hypothesis that their reward systems need growing stimulation."

A more technical description of this study from a review of the literature by Kuhn & Gallinat - Neurobiological Basis of Hypersexuality (2016).

"The more hours participants reported consuming pornography, the smaller the BOLD response in left putamen in response to sexual images. Moreover, we found that more hours spent watching pornography was associated with smaller gray matter volume in the striatum, more precisely in the right caudate reaching into the ventral putamen. We speculate that the brain structural volume deficit may reflect the results of tolerance after desensitization to sexual stimuli."

15) Sexual Desire, not Hypersexuality, is Related to Neurophysiological Responses Elicited by Sexual Images (2013) - This EEG study was touted in the media as evidence against the existence of porn addiction. Not so. In line with the Cambridge University brain scan studies, this EEG study reported greater cue-reactivity to porn correlated with less desire for partnered sex. To put another way - individuals with more brain activation and cravings for porn would rather masturbate to porn than have sex with a real person. Study spokesperson Nicole Prause claimed that porn users merely had "high libido", yet the results of the study say something quite different.Four peer-reviewed papers expose the truth: 1, 2, 3, 4, 5. Also see the extensive YBOP critique.

16) Modulation of Late Positive Potentials by Sexual Images in Problem Users and Controls Inconsistent with "Porn Addiction" (2015) - Another Nicole Prause EEG study. This time comparing the 2013 subjects from the above study to an actual control group. The results: compared to controls, "porn addicts" had less response to one-second exposure to photos of vanilla porn. The lead author, Nicole Prause, claimed these results debunk porn addiction (contrary to caims no studies falsify the porn addiction model). However, these findings align perfectly with Kühn & Gallinat (2014), which found that more porn use correlated with less brain activation in response to pictures of vanilla porn. Put simply, frequent porn users were desensitized to static images of vanilla porn. They were bored (habituated or desensitized). Five peer-reviewed papers agree that this study actually found desensitization/habituation in frequent porn users: 1, 2, 3, 4. 5, 6. (also see this extensive YBOP critique). By the way, another EEG study found that greater porn use in women correlated with less brain activation to porn.

17) Masturbation and Pornography Use Among Coupled Heterosexual Men With Decreased Sexual Desire: How Many Roles of Masturbation? (2015) - Masturbating to porn was related with decreased sexual desire and low relationship intimacy. Excerpts:

"Among men who masturbated frequently, 70% used pornography at least once a week. A multivariate assessment showed that sexual boredom, frequent pornography use, and low relationship intimacy significantly increased the odds of reporting frequent masturbation among coupled men with decreased sexual desire."

"Among men [with decreased sexual desire] who used pornography at least once a week [in 2011], 26.1% reported that they were unable to control their pornography use. In addition, 26.7% of men reported that their use of pornography negatively affected their partnered sex and 21.1% claimed to have attempted to stop using pornography."

18) Use of pornography in a random sample of Norwegian heterosexual couples (2009) - Porn use was correlated with more sexual dysfunctions in the man and negative self perception in the female. The couples who did not use porn had no sexual dysfunctions. A few excerpts from the study:

In couples where only one partner used pornography, we found more problems related to arousal (male) and negative (female) self-perception.

In those couples where one partner used pornography there was a permissive erotic climate. At the same time, these couples seemed to have more dysfunctions.

The couples who did not use pornography... may be considered more traditional in relation to the theory of sexual scripts. At the same time, they did not seem to have any dysfunctions.

Couples who both reported pornography use grouped to the positive pole on the ‘‘Erotic climate’’ function and somewhat to the negative pole on the ‘‘Dysfunctions’’ function.

19) Erectile Dysfunction, Boredom, and Hypersexuality among Coupled Men from Two European Countries (2015) - Survey reported a strong correlation between erectile dysfunction and measures of hypersexuality. The study omitted correlation data between erectile functioning and pornography use, but noted a significant correlation. An excerpt:

Among Croatian and German men, hypersexuality was significantly correlated with proneness to sexual boredom and more problems with erectile function.

20) An Online Assessment of Personality, Psychological, and Sexuality Trait Variables Associated with Self-Reported Hypersexual Behavior (2015) – Survey reported a common theme found in several other studies listed here: Porn/sex addicts report greater arousabilty (cravings related to their addiction) combined with poorer sexual function (fear of experiencing erectile dysfunction).

Hypersexual" behavior represents a perceived inability to control one's sexual behavior. To investigate hypersexual behavior, an international sample of 510 self-identified heterosexual, bisexual, and homosexual men and women completed an anonymous online self-report questionnaire battery.

Thus, the data indicated that hypersexual behavior is more common for males, and those who report being younger in age, more easily sexually excited, more sexually inhibited due to the threat of performance failure, less sexually inhibited due to the threat of performance consequences, and more impulsive, anxious, and depressed

21) Study sees link between porn and sexual dysfunction (2017) - The findings of an upcoming study presented at the American Urological Association's annual meeting. A few excerpts:

Young men who prefer pornography to real-world sexual encounters might find themselves caught in a trap, unable to perform sexually with other people when the opportunity presents itself, a new study reports. Porn-addicted men are more likely to suffer from erectile dysfunction and are less likely to be satisfied with sexual intercourse, according to survey findings presented Friday at the American Urological Association's annual meeting, in Boston.

"The rates of organic causes of erectile dysfunction in this age cohort are extremely low, so the increase in erectile dysfunction that we have seen over time for this group needs to be explained," Christman said. "We believe that pornography use may be one piece to that puzzle".

22) Associative pathways between pornography consumption and reduced sexual satisfaction (2017) - This study is found in both lists. While it links porn use to lower sexual satisfaction, it also reported that frequency of porn use was related to a preference (or need?) for porn over people to achieve sexual arousal. An excerpt:

Finally, we found that frequency of pornography consumption was also directly related to a relative preference for pornographic rather than partnered sexual excitement. Participants in the present study primarily consumed pornography for masturbation. Thus, this finding could be indicative of a masturbatory conditioning effect (Cline, 1994; Malamuth, 1981; Wright, 2011). The more frequently pornography is used as an arousal tool for masturbation, the more an individual may become conditioned to pornographic as opposed to other sources of sexual arousal.

23) “I think it has been a negative influence in many ways but at the same time I can’t stop using it”: Self-identified problematic pornography use among a sample of young Australians (2017) - Online survey of Australians, aged 15-29.  Those who had ever viewed pornography (n=856) were asked in an open-ended question: ‘How has pornography influenced your life?’.

Among participants who responded to the open-ended question (n=718), problematic usage was self-identified by 88 respondents. Male participants who reported problematic usage of pornography highlighted effects in three areas: on sexual function, arousal and relationships. Responses included “I think it has been a negative influence in many ways but at the same time I can’t stop using it” (Male, Aged 18–19). Some female participants also reported problematic usage, with many of these reporting negative feelings like guilt and shame, impact on sexual desire and compulsions relating to their use of pornography. For example as one female participant suggested; “It makes me feel guilty, and I’m trying to stop. I don’t like how I feel that I need it to get myself going, it’s not healthy.” (Female, Aged 18–19)

24) Exploring the Relationship Between Erotic Disruption During the Latency Period and the Use of Sexually Explicit Material, Online Sexual Behaviors, and Sexual Dysfunctions in Young Adulthood (2009) - Study examined correlations between current porn use (sexually explicit material - SEM) and sexual dysfunctions, and porn use during "latency period" (ages 6-12) and sexual dysfunctions. The average age of participants was 22. While current porn use correlated with sexual dysfunctions, porn use during latency (ages 6-12) had an even stronger correlation with sexual dysfunctions. A few excerpts:

Findings suggested that latency erotic disruption by way of sexually explicit material (SEM) and/or child sexual abuse may be associated to adult online sexual behaviors.

Furthermore, results demonstrated that latency SEM exposure was a significant predictor of adult sexual dysfunctions.

We hypothesized that exposure to latency SEM exposure would predict adult use of SEM. Study findings supported our hypothesis, and demonstrated that latency SEM exposure was a statistically significant predictor of adult SEM use. This suggested that individuals who were exposed to SEM during latency, may continue this behavior into adulthood. Study findings also indicated that latency SEM exposure was a significant predictor of adult online sexual behaviors.

23) Lecture describing upcoming studies - by Urology professor Carlo Foresta, president of the Italian Society of Reproductive Pathophysiology - The lecture contains the results of longitudinal and cross-sectional studies. One study involved a survey of high school teens (pages 52-53). The study reported that sexual dysfunction doubled between 2005 and 2013, with low sexual desire increasing 600%.

  • The percentage of teens that experienced alterations of their sexuality: 2004/05: 7.2%, 2012/13: 14.5%
  • The percentage of teens with low sexual desire: 2004/05: 1.7%, 2012/13: 10.3% (that's a 600% increase in 8 years)

Foresta also describes his upcoming study, "Sexuality media and new forms of sexual pathology sample 125 young males, 19-25 years" (Italian name - "Sessualità mediatica e nuove forme di patologia sessuale Campione 125 giovani maschi"). The results from the study (pages 77-78), which used the International Index of Erectile Function Questionnaire, found that regular porn users scored 50% lower on sexual desire domain and 30% lower of the erectile functioning domain.

24) (not peer-reviewed) Here's an article about an extensive analysis of comments and questions posted on MedHelp concerning erectile dysfunction. What's shocking is that 58% of the men asking for help were 24 or younger. Many suspected that internet porn could be involved as described in the results from the study -

The most common phrase is “erectile dysfunction” – which is mentioned more than three times as often as any other phrase – followed by “internet porn,” “performance anxiety,” and “watching porn.”

Clearly, porn is a frequently discussed subject: “I have been viewing internet pornography frequently (4 to 5 times a week) for the past 6 years,” one man writes. “I am in my mid-20s and have had a problem getting and maintaining an erection with sexual partners since my late teens when I first started looking at internet porn.”

Article about the latest spin campaign: Sexologists Deny Porn-induced ED by Claiming Masturbation Is the Problem (2016)


LEY: However, Dr. Zimbardo fails to acknowledge or consider the tremendous social changes which occurred with the invention of erectile performance medications, and which dramatically increased willingness to disclose erectile dysfunction, by reducing the shame associated with it.

RESPONSE: The tremendous rise in youthful ED and low sexual desire is documented in this article. Ley cited nothing as, once again, there is no empirical support for his claim that the introduction of Viagra (1997) led to men finally tell the truth in studies on sexual dysfunction (13 years later). These are not the rates of men visiting their doctors to request ED medication. The ED rates cited refer only to peer-reviewed studies (usually anonymous) on population wide rates of sexual dysfunction. To put it another way, the ‘Viagra hypothesis’ is claiming that in every single study published between 1948 and 2010, in countries all over the world, the young male participants consistently lied about their erectile functioning. Then, all of a sudden, in 2010 all the young men (and only the young men) began to tell the truth about their ED problems. This is absurd. Ley's claim is like saying that the introduction of aspirin led to anonymous studies reporting a 1000% increase in headaches among only one age group. A few more points that refute the "Viagra causes ED" claim:

1) The claim about "willingness to disclose" doesn't apply here. The ED and low libido rates are not rates for men visiting their doctor for erectile dysfunction. Instead, the ED and low libido rates come from studies mostly employing anonymous standardized questionnaires where men rate the quality of their erections and arousal during sex. That has not changed because Viagra was introduced.

2) The exponential rise in ED and low libido rates occurred only in men under 40. This alone refutes Ley's claim.

3) In this same time period there was a concomitant increase in low sexual desire (and evidence of increases in difficulty orgasming too). The largest US study from 1992 reported 5% of men under 40 had low sexual desire.

  • A 2014 Canadian study reported low sexual desire in 24% of 16-21 year olds!
  • A 2014 survey of Croatian men 40 and under reported low sexual desire rates of 37%.
  • Again, this aligns with a 2015 study on Italian high school seniors (18-19), which found that 16% of those who use porn more than once per week reported abnormally low sexual desire. Non-porn users reported 0% low sexual desire (as one would expect in 18-year olds).

4) These days, ED rates are often higher for young men than for old men (who obviously used less internet porn growing up). The 2014 Canadian study reported that 53.5% of males aged 16-21 have symptoms indicative of a sexual problem. Erectile dysfunction was the most common (27%), followed by low sexual desire (24%), and problems with orgasm (11%).

  • Reality check: these rates are higher than those reported for 50-60 year olds in the large 1992 study on men 18-60!

5) Two studies published AFTER Viagra was introduced report higher ED rates in young men. If Viagra ads caused ED in men, wouldn't we see far higher rates in older men? These were studies of the same European countries using the same questionnaires (GSSAB). Instead rates in young men are abnormally high now.

  • The 2001-2002 ED rates for men 40-80 were about 13% in Europe.
  • By 2011, ED rates in young Europeans, 18-40, ranged from 14-28%.

6) Common sense: There's absolutely no evidence to suggest that a young man today would be any less embarrassed or ashamed when experiencing erectile dysfunction than a young man was in 1995 (once again, shame is irrelevant as all data came from studies using anonymous questionnaires). 


LEY: Indeed, multiple peer-reviewed articles have now been published which found no evidence for PIED, but instead, found the opposite effect, that porn use and concomitant masturbation, is likely to result in delayed orgasm.

RESPONSE TO FIRST PART: "multiple peer-reviewed articles have now been published which found no evidence for PIED"

First, there's only one way to confirm whether erectile dysfunction is porn-induced (PIED) or not: Eliminate porn use for a extended period of time and see if the sufferer regains normal erectile functioning. Three studies have done this, thus proving the existence of porn-induced sexual dysfunctions. See this list of 23 studies linking porn use/sex addiction to sexual problems (the demonstrate causation as participants eliminated porn use and healed chronic sexual dysfunctions).

had a subject with suspected porn-induced sexual problems abstain from porn. Guess what? That's 3 for 3 on studies assessing porn-induced sexual problems.

The "multiple articles" that Ley could be referring to are really only two papers that claimed to have found little relationship between the amount of porn use and erectile dysfunction. The first paper, Prause & Pfaus 2015, has been so roundly criticized for missing data, unsupported claims, poor methodology, and statements that are in direct opposition of its data, that it is, in effect, discredited. It was formally critiqued in an academic journal by a researcher and reproductive medicine doctor. This lay critique exposes even more holes in the paper.

A second paper (Landripet & Stulhofer) found extraordinarily high rates of low libido and ED in men under 40. Contrary to Ley's claims, the study actually found a few correlations between ED and porn use. The abstract doesn't mention a pretty important correlation: Only 40% of the Portuguese men used porn "frequently," while the 60% of the Norwegians used porn "frequently." The Portuguese men had far less sexual dysfunction than the Norwegians.

Elsewhere, the authors acknowledge a statistically significant association between more frequent porn use and ED, but claim the effect size was small. However, this claim may be misleading according to an MD who is a skilled statistician and has authored many studies:

Analyzed a different way (Chi Squared), ... moderate use (vs. infrequent use) increased the odds (the likelihood) of having ED by about 50% in this Croatian population. That sounds meaningful to me, although it is curious that the finding was only identified among Croats.

The authors blow this finding off and ignore it in reaching their conclusions, as they also ignore Danish porn researcher Gert Martin Hald's formal commentary about the study, in which he says:

However, in pornography research, the interpretation of “size” may depend as much on the nature of the outcome studied as the magnitude of the relationship found. Accordingly, if the outcome is to be considered “sufficiently adverse” (e.g., sexual aggressive behaviors), even small effect sizes may carry considerable social and practical significance [2].

Gert Martin Hald's editorial comments emphasize the need to assess more variables (mediators, moderators) than just frequency per week in the last 12 months:

Third, the study does not address possible moderators or mediators of the relationships studied nor is it able to determine causality. Increasingly, in research on pornography, attention is given to factors that may influence the magnitude or direction of the  relationships studied (i.e., moderators) as well as the pathways through which such influence may come about (i.e., mediators). Future studies on pornography consumption and sexual difficulties may also benefit from an inclusion of such focuses.

In other words, using only a single limited variable such as "hours of use in the last month" may not reveal anything. It's already established in studies on both internet porn addiction (1, 2, 3) and internet video-gaming addiction, that symptoms do not correlate with "hours of use." Instead of just current hours of use, a combination of variables appears to correlate best with porn-induced ED. These may include:

  1. Ratio of masturbation to porn versus masturbation without porn
  2. Ratio of sexual activity with a person versus masturbation to porn
  3. Gaps in partnered sex (where one relies only on porn)
  4. Virgin or not
  5. Total hours of use
  6. Years of use
  7. Age started using porn
  8. Escalation to new genres
  9. Development of porn-induced fetishes (from escalating to new genres of porn)
  10. Level of novelty per session (i.e. compilation videos, multiple tabs)
  11. Addiction-related brain changes or not
  12. Presence of hypersexuality/porn addiction

The better way to research the phenomenon of porn-induced sexual dysfunctions, is to remove the variable of internet porn use and observe the outcome. Such research reveals causation instead of correlations open to interpretation. My site has documented a few thousand men who removed internet porn and recovered from chronic sexual dysfunctions.

SUMMARY: Only one valid study has attempted to correlate the amount of porn use with ED. Contrary to Ley's claim, this study reports at least one meaningful correlation between ED and porn use. Offsetting this single "brief communication," we have several studies reporting relationships between porn use in young men and ED, anorgasmia, low sexual desire, delayed ejaculation and lower brain activation to sexual images. 


LEY: "Indeed, multiple peer-reviewed articles have now been published which found no evidence for PIED, but instead, found the opposite effect, that porn use and concomitant masturbation, is likely to result in delayed orgasm."

RESPONSE TO SECOND PART: "but instead, found the opposite effect, that porn use and concomitant masturbation, is likely to result in delayed orgasm."

How bizarre. Ley appears to be claiming that delayed orgasm is "the opposite" of erectile dysfunction. Hats off to Ley. This has to be the most over-the-top bits of spin he's ever written. Ley appears to be spinning the results of this 2015 study on men with hypersexuality disorders - “Patient Characteristics by Type of Hypersexuality Referral: A Quantitative Chart Review of 115 Consecutive Male Cases”.

The study classified 27 men as “avoidant masturbators,” meaning they masturbated to porn one or more hours per day or more than 7 hours per week. 71% of the compulsive porn users reported sexual functioning problems, with 33% reporting delayed ejaculation.

What sexual dysfunction do 38% of the remaining men have? The study doesn't say, and the authors have publicly refused to give details. The two other primary choices for male sexual dysfunction are ED and low libido. You do the math. 

In reality, porn-induced delayed ejaculation is often a precursor to porn-induced erectile dysfunction. Like ED, delayed ejaculation is one of the primary reasons men choose to abstain from porn in search of recovery. This page contains many stories by men who recovered from porn-induced delayed ejaculation. Delayed ejaculation arises from the same brain changes that eventually lead to full blown PIED (i.e. desensitization/habituation and conditioning one's sexual arousal to everything associated with internet porn use instead of to real partners). 

SUMMARY: Ley is trying to spin a 71% rate of sexual dysfunction in compulsive porn users into evidence that porn use is really beneficial!


LEY: Numerous research studies in the past year from authors such as Joshua Grubbs of Case Western  and Alexander Stulhofer of Croatia, have consistently confirmed the role of morality and religiosity in the backgrounds of those who identify as sex or porn addicts. In other words, both of these researchers have demonstrated that sex/porn addicts are not in fact watching more porn or having more sex than anyone else - they just feel worse and more conflicted about the sex they are having.

RESPONSE: Numerous? Since there are no citations let's consider the two studies mentioned: In the case of Grubbs and Stulhofer how have the researchers distinguished between shame related to sex/porn and shame from the inability to control use despite negative consequences? This is left unexplained. (In other words, they haven't.)

As for Stulhofer paper (Is High Sexual Desire a Facet of Male Hypersexuality? Results from an Online Study) It's conclusion says:

Compared to the rest of the sample, men in the hypersexuality group had significantly higher odds of being single, not exclusively heterosexual, religious, depressed, prone to sexual boredom, experiencing substance abuse consequences, holding negative attitudes toward pornography use, and evaluating one's sexual morality more negatively. In contrast, the high sexual desire group differed from controls only in reporting more positive attitudes toward pornography use.

First, Stulhofer reported very little overlap between the hypersexuality group (sex/porn addicts) and the high libido group. As explained above, this refutes Ley's claim that "hypersexuals" simply have high sexual desire. 

Second, the addicts held negative attitudes towards pornography use. Is it really so odd for an addict to feel bad about being unable to control use despite the negative consequences? Wouldn't we expect an out-of-control alcoholic to have negative feelings towards drinking alcohol? What does the phrase "evaluating one's sexual morality" mean when it is applied to out-of-control porn use that is impacting one's life negatively? It could be as simple as, "Addicts experience negative feelings towards their addiction."

As for Grubbs et al's results, might they be explained, in part, by the fact that religious people are generally better informed (or, in some cases overly informed) about the risks of internet porn use, so they "connect the dots" more quickly and in higher percentages when asked about their addiction? Religious people are probably also more inclined to try stopping, and therefore more likely to experience distressing withdrawal symptoms or recognize their inability to control their (perhaps) infrequent use. Withdrawal symptoms are anxiety-producing in themselves. In contrast, the non-religious simply don't think to experiment with stopping porn so they may not experience severe cravings and withdrawal symptoms unless they slam into a wall o' hurt and try quitting.

If religion were the key factor in a "belief in porn addiction," one would expect the majority of those on the recovery forums to be religious. That is not what we see. The most popular English-speaking porn-recovery forum we know of, r/nofap, polled their members (back in 2012). 60+% of their members were non-religious (23% Christian). Shortly after that poll, a "Christian nofap" was founded, which means that the percentage of religious on r/nofap is even lower now. In a later member survey, only 11% were quitting for religious reasons. Since that first poll, the number of members on r/nofap has exploded. It's 170K+ members now, and overwhelming non-religious.

Grubbs needs better methodology - methodology that does not conflate shame arising from "being unable to quit an addiction that is producing negative effects" with shame arising from porn's content. Two quite different phenomena.


Is it Ethical for a Psychologist to Consistently Attack a Self-Help Group?

Ley suggests that NoFap, a porn-recovery forum, is somehow dangerous. In this piece he continues his ongoing defamatory attacks on the NoFap community. If he disagrees with the scientific findings on internet porn users' brains (which support the efforts on NoFap), he should take it up with the researchers themselves, not take it out on a self-help community. This is like attacking cancer patients because one disagrees with oncology protocols. (Nofap moderator dismantles Ley's article)

Not only is it disturbing that Ley attacks people endeavoring to recover from the effects of overconsuming internet porn, it may be a violation of various principles of the American Psychological Association. The APA has 5 guiding principles for all psychologists and Ley's chronic disparaging of NoFap appears to violate all 5:

Principle A: Beneficence 4.05 and Nonmaleficence (in part)

... In their professional actions, psychologists seek to safeguard the welfare and rights of those with whom they interact professionally and other affected persons… .... Because psychologists' scientific and professional judgments and actions may affect the lives of others, they are alert to and guard against personal, financial, social, organizational or political factors that might lead to misuse of their influence...

Principle B:  Fidelity and Responsibility (in part)

Psychologists … are aware of their professional and scientific responsibilities to society and to the specific communities in which they work. Psychologists uphold professional standards of conduct, clarify their professional roles and obligations, accept appropriate responsibility for their behavior and seek to manage conflicts of interest that could lead to exploitation or harm. ...

Principle C: Integrity (in part)

Psychologists seek to promote accuracy, honesty and truthfulness in the science, teaching and practice of psychology. In these activities psychologists do not steal, cheat or engage in fraud, subterfuge or intentional misrepresentation of fact.

Principle D: Respect for People’s Rights (in part)

Psychologists exercise reasonable judgment and take precautions to ensure that their potential biases, the boundaries of their competence and the limitations of their expertise do not lead to or condone unjust practices.

Principle E: Dignity (in part)

Psychologists respect the dignity and worth of all people, and the rights of individuals to privacy, confidentiality, and self-determination.


Update: It should be noted that both David Ley profits from denying sex and porn addiction. At the end of this Psychology Today blog post Ley states:

"Disclosure: David Ley has provided testimony in legal cases involving claims of sex addiction."

Ley also makes money selling two books which deny sex and porn addiction ("The Myth of Sex Addiction", 2012 and "Ethical Porn for Dicks", 2016). Pornhub (which is owned by porn ginat mindgeek) is one of the five Amazon.com endorsements listed for Ley's 2016 book about porn. Finally, David Ley makes money via CEU seminars, where he promotes the ideas presented in his two books.