YBOP response to claims in a David Ley comment (January, 2016)

Printer-friendly version

I was altered to Ley's comment and asked to respond directly on the above thread. Since my response was blocked, I decided to post an easier to read version on YBOP.

Before I address David Ley's claims it must be noted that he consistently fails to mention the 39 neuroscience-based studies on porn users published in the last few years (and 16 reviews of the literature and commentaries by some of the top neuroscientists in the world). So far, the results of every "brain study" (MRI, fMRI, EEG, neuropsychological, hormonal) 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 greater porn use is associated with erectile dysfunction, decreased libido, and reduced neural response to images of vanilla porn. The up-to-date list of current "brain studies" is here. Clicking on the name of the study leads to the original paper.

These 39 studies also align with over 280 internet addiction "brain studies" (PET, MRI, fMRI, EEG) published in the last few years. Without exception, these studies reported the same addiction-related brain changes as seen in substance addicts. Internet porn addiction is, in fact, a subtype of internet addiction, as this recent review of the neuroscience literature pointed out: "Neuroscience of Internet Pornography Addiction: A Review and Update (2015)"

LEY: "ED was only truly acknowledged in the 90-‘s, after the advent of Viagra. The higher rates of admitted ED since then, are due to the decreased shame in acknowledging it".

YBOP RESPONSE: The tremendous rise in youthful ED and low sexual desire is documented in this peer-reviewed paper by 7 US Navy doctors: Is Internet Pornography Causing Sexual Dysfunctions? A Review with Clinical Reports (2016).

Ley cited nothing as, once again, there is no empirical support for his claim that the introduction of Viagra led to men finally tell the truth in studies on sexual dysfunction. We are not talking about an increase in men visiting their doctors for ED medication. The ED rates refer only to peer-reviewed studies (usually anonymous surveys) on population wide rates of sexual dysfunction. To put it another way, Ley is claiming that in every single study published between 1948 and 2010, in countries all over the world, the male participants consistently lied about their erectile functioning. Then in 2010 (13 years after Viagra was introduced) all young men, and only the young men, started to tell the truth in anonymous questionnaires about erectile functioning. That is absurd. Ley's claim is like saying that the introduction of aspirin caused studies to report a 1000% increase in headaches among one age group. A few 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. 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 questionaires). 

LEY: "The attempt to distinguish porn addiction from sex addiction is a common trope in believers of porn addiction."

RESPONSE: The attempt to conflate porn addiction with sex addiction is the common tactic of Dr. Ley. He does this so he can trot out Tiger Woods and Bill Clinton, while ignoring that many young men today spend their adolescence watching hard-core streaming videos, and do so for years prior to attempting sex. Sitting alone surfing through tube sites is not sex. Many are still virgins due to their overuse of streaming porn (ED rates are 27-33% for men under 40). I suggest our article - Porn Addiction Is Not Sex Addiction--And Why It Matters.

LEY: "Unfortunately, their real argument is that it is masturbation to porn which is addictive – the overwhelming majority of porn consumption involves masturbation."

RESPONSE: Nice try. Every study cited was about porn use. This is another common tactic of Dr. Ley. He cleverly attempts to move the conversation away from Internet porn and onto masturbation. He does this so he can employ the same tired talking points of Kellogg, shame, religion, fear of sex... Everyone knows masturbation doesn't cause ED. None of the studies cited were about masturbation. Please Dr. Ley, stay on topic. This isn't about shame, as the primary reason men abstain from porn is to heal porn-induced sexual dysfunctions. These men want to have sex, enjoyable sex, and most are unmarried.

LEY: "The brain studies on porn effect are interesting."

RESPONSE: Dr. Ley, why is it that you always claim there is no scientific support for porn/sex addiction - even though there are now 37 neuroscience-based studies (MRI, fMRI, EEG, Neurospych, Hormonal) providing strong support for the addiction model? How can we take you seriously when you are either ignorant of the current state of the neuroscience, or willfully ignoring it?

LEY: "What they really seem to demonstrate is that people with higher libido and higher sensation-seeking gravitate towards greater porn use, as a result of pre-existing neurological characteristics."

RESPONSE: This same tired claim about porn addiction or sex addiction being nothing more than high libido doesn't fly. It has been thoroughly falsified in the peer-reviewed literature.

You may have seen the "high libido" claim in Ley's Psychology Today blog post with the catchy title: "Your Brain on Porn - It's NOT Addictive". Ley's 3-year old blog post is not about the science behind YBOP. Instead, it's about a single EEG study, whose lead author is Nicole Prause. Both Ley and Prause claimed that the study's (Steele et al. 2013) findings support the premise that porn/sex addiction is nothing more than "high sexual desire."

Contrary to claims by Ley and Nicole Prause, Steele et al., 2013 reported greater cue-reactivity (higher EEG) 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 preferred masturbating to porn over having sex with a real person.

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 in no way match the concocted headlines 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) for “porn addicts” when compared to controls. 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 (six peer-reviewed papers agree with YBOP: 1, 2, 3, 4. 5, 6.)

Put simply, the results of Prause's second EEG study indicate LESS sexual arousal - not higher desire. In fact, Nicole Prause stated in this 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: "No causality has been demonstrated, indicating that porn causes any brain changes, certainly none which are distinct from other forms of entertainment such as television or pro-sports."

RESPONSE: This one sentence demonstrates a profound lack of knowledge related to how research works, and ignorance of the brain changes involved in addiction (more in my next answer). 

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

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 as thousands of young men stop porn as a way to alleviate chronic non-organic erectile dysfunction (caused by porn use).

To this date only 6 studies have removed porn and observed the results. All 6 found significant changes. Four of those studies demonstrated causation as compulsive porn users healed severe sexual dysfunctions by quitting porn.

  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 porn. The subjects who tried to abstain from porn experience big changes: they scored much better on their ability to delay gratification. The study 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.”

  1. A Love That Doesn’t Last: Pornography Consumption and Weakened Commitment to One’s Romantic Partner (20120” – The study had subjects try to abstain from porn use for 3 weeks. Comparing the two groups, those who continued using pornography reported lower levels of commitment than control participants.
  2. 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.
  3. 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
  4. 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. Eliminating porn-based masturbation led to remission of sexual dysfunctions on 19 of the 35 men. The remaining 16 men stopped therapy or could not quit using porn. 
  5. 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.

Ley's claim that addiction-induced brain changes are no different from those induced by other forms of entertainment is downright scary. In reality, the brain changes caused by addiction are quite distinct from those caused by watching "Gilligan's Island". 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 behaviours 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 week 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 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, 4) Dysfunctional stress circuits. All 4 of these brain changes have been identified among the 37 neuroscience studies on porn users:

  1. Studies reporting sensitization or cue-reactivity in porn users/sex addicts: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.
  2. Studies reporting desensitization or habituation in porn users/sex addicts: 1, 2, 3, 4, 5, 6.
  3. Studies reporting poorer executive functioning (hypofrontality) or altered prefrontal activity in porn users/sex addicts: 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 22 studies provide support for porn/sex addiction, the world's top addiction experts do also. The little bubble he has carved out where porn addiction cannot possibly exist is quickly becoming irrelevant.

LEY: "I agree, watching lots of porn, television or sports IS likely to affect your brain. This is called “learning.

RESPONSE: This is a typical tactic - to absurdly suggest that all learning is equal. PTSD involves learning. Would Dr. Ley advise men with battle-induced PTSD to "just get over it," because it's really no different than the learning that occurs while watching soccer on TV? Reality: The mechanisms of addiction in the addicted have been studied for nearly 60 years, in comparison with normal controls. Again, the differences (from normal brains) have been elucidated down to the cellular, protein, and epigenetic levels.

While learning and memory are most certainly involved in addiction, addiction involves a very specific type of pathological learning addiction neuroscientist refer to as "sensitization." This type of learning involves set changes in the reward canter which lead to cravings to use. The incentive sensitization theory of addiction is the predominant model of addiction. 19 of the 37 neuroscience-based studies on this page looked for sensitization in porn addicts - and found it. (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.)

As mentioned above, the 37 studies reported other major addiction-related brain changes (sensitization, desensitization, hypofrontality and dysfunctional stress circuits) in porn/sex addicts. No, Dr. Ley, these brain changes are not caused by "I Love Lucy" reruns. Together these 4 multifaceted brain alterations manifest behaviorally as what we recognize as addiction: 1) Compulsion to use, 2) Continued use in spite of adverse consequences, 3) Inability to Control use, 4) Cravings - psychological or physical.

Ley's talking point is very similar to waht sexologist Marty Klein said in reply to a Zimbardo & Wilson article where he claimed that the brain response to watching porn is no different than watching a sunset:

"Besides, our brain responds in this same observable way when we cuddle a grandchild or enjoy a sunset."

The Ley and Klein claim was long ago tested and debunked, in a 2000 fMRI study: "Cue-induced cocaine craving: neuroanatomical specificity for drug users and drug stimuli. The study had cocaine addicts and healthy controls view films of: 1) individuals smoking crack cocaine, 2) outdoor nature scenes, and 3) explicit sexual content. The results: cocaine addicts had nearly identical brain activation patterns when viewing porn and viewing cues related to their addiction. (Incidentally, both cocaine addicts and healthy controls had the same brain activation patterns for porn.) However, for bot

h the addicts and controls, brain activation patterns when viewing nature scenes were completely different from the patterns when viewing for porn. Goodbye silly talking point!

LEY: "Perhaps you can start with the brain changes caused by conservativism"

RESPONSE: I am a far left liberal and an agonistic, but this isn't about me. However, Ley's comment was under a post about r/NoFap. Contrary to Ley's chronic mischaracterizations of NoFap, the largest survey conducted on NoFap members found that:

  • 60% of r/NoFap members identify as atheists or agnostics.
  • Only 11% of r/nofap members said they were quitting porn for religious or moral reasons.

The facts don't fit the spin promulgated in Dr. Ley's Psychology Today hit piece on r/NoFap. Notice that Ley refused to allow comments under his NoFap blog post, which is almost unheard of for a Psychology Today post. See this thread on NoFap.org concerning Ley's blog post:

LEY: "I recently had the opportunity to interview Isaac Abel, who famously wrote a few popular pieces on Porn-Related ED. Two years later, he’s still not watching porn, but still struggles with ED"

RESPONSE: That's really sad. This may point to the vulnerability of the adolescent brain. I have read recovery stories of young men who grew up using internet porn needing 2-3 years to regain erectile health. Even after 3 years they continue to see improvements. Older men, who did not have access to streaming videos during adolescence, may need only a month or two to regain normal sexual functioning. FYI - below are over 4,000 documented stories of recovery from porn-induced sexual problems. Perhaps you could interview one these guys:

I find it telling that Ley ignores thousands of documented accounts of young men regaining erectile function and libido by removing a single variable (porn use), yet places tremendous value in a single story where the young man has yet to heal his ED.

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.