Porn Use & Sex Addiction Studies

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  • Research is needed on sex and porn addicts' brainsThe list of studies can be found below this introduction. An (L) in front of the link indicates a lay article, usually about a study.

Although this section is named "Porn Use & Sex  Addiction," Internet porn addiction is not sex addiction (see Porn Addiction Is Not Sex Addiction--And Why It Matters). Internet porn addiction is considered by many experts to a subset of internet addiction.

Several recent reviews of the literature lend support to the addiction model:

  1. See this 2015 paper by two medical doctors: Sex Addiction as a Disease: Evidence for Assessment, Diagnosis, and Response to Critics, which provides a chart from that takes on specific criticisms and offers citations that counter them.
  2. For a thorough review of the neuroscience literature related to Internet addiction subtypes, with special focus on internet porn addiction, see - Neuroscience of Internet Pornography Addiction: A Review and Update (2015). The review also critiques two recent headline-grabbing EEG studies which purport to have "debunked" porn addiction.
  3. Is Internet Pornography Causing Sexual Dysfunctions? A Review with Clinical Reports (2016) - An extensive review of the literature on porn-induced sexual problems by 7 US Navy doctors and Gary Wilson. The review provides the latest data revealing a tremendous rise in youthful sexual problems..The paper also reviews the neurological studies related to porn addiction and sexual conditioning. The doctors provide 3 clinical reports of men who developed porn-induced sexual dysfunctions. A second 2016 paper by Gary Wilson discusses the importance of studying the effects of porn by having subjects abstain from porn use: Eliminate Chronic Internet Pornography Use to Reveal Its Effects (2016).
  4. This short review - Neurobiology of Compulsive Sexual Behavior: Emerging Science (2016) - 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."
  5. A 2016 review of compulsive sexual behaviors (CSB) - Should compulsive sexual behavior be considered an addiction? (2016) - concluded that: "Overlapping features exist between CSB 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." Most of the neuroscience supporting the existence of "sex addiction" actually comes from studies on porn users, not sex addicts. Conflating internet porn addiction with sex addiction weakens the paper.
  6. Compulsive Sexual Behaviour as a Behavioural Addiction: The Impact of the Internet and Other Issues (2016). Excerpts: "more emphasis is needed on the characteristics of the internet as these may facilitate problematic sexual behaviour." and "clinical evidence from those who help and treat such individuals should be given greater credence by the psychiatric community."
  7. While the term "hypersexuality" should be discarded, this is a good review by Max Planck neuroscientists Neurobiological Basis of Hypersexuality (2016). Excerpt: "Taken together, the evidence seems to imply that alterations in the frontal lobe, amygdala, hippocampus, hypothalamus, septum, and brain regions that process reward play a prominent role in the emergence of hypersexuality. Genetic studies and neuropharmacological treatment approaches point at an involvement of the dopaminergic system."
  8. Cybersex Addiction (2015). Excerpts: "In recent articles, cybersex addiction is considered a specific type of Internet addiction. Some current studies investigated parallels between cybersex addiction and other behavioral addictions, such as Internet Gaming Disorder. Cue-reactivity and craving are considered to play a major role in cybersex addiction. Neuroimaging studies support the assumption of meaningful commonalities between cybersex addiction and other behavioral addictions as well as substance dependency."
  9. Searching for clarity in muddy water: future considerations for classifying compulsive sexual behavior as an addiction (2016) - Excerpts: We recently considered evidence for classifying compulsive sexual behavior (CSB) as a non-substance (behavioral) addiction. Our review found that CSB shared clinical, neurobiological and phenomenological parallels with substance-use disorders. Although the American Psychiatric Association rejected hypersexual disorder from DSM-5, a diagnosis of CSB (excessive sex drive) can be made using ICD-10. CSB is also being considered by ICD-11.
  10. Integrating psychological and neurobiological considerations regarding the development and maintenance of specific Internet-use disorders: An Interaction of Person-Affect-Cognition-Execution model (2016). - A review of the mechanisms underlying the development and maintenance of specific Internet-use disorders, including "Internet-pornography-viewing disorder". The authors suggest that pornography addiction (and cybersex addiction) be classified as internet use disorders and placed with other behavioral addictions under substance-use disorders as addictive behaviors.
  11. Neuroscientific Approaches to Online Pornography Addiction (2017) - Excerpt: In the last two decades, several studies with neuroscientific approaches, especially functional magnetic resonance imaging (fMRI), were conducted to explore the neural correlates of watching pornography under experimental conditions and the neural correlates of excessive pornography use. Given previous results, excessive pornography consumption can be connected to already known neurobiological mechanisms underlying the development of substance-related addictions.

At this time over a dozen studies have directly examined the brains of porn users & sex addicts (See this page for critiques and analysis of highly questionable and misleading studies):

  1. Brain Structure and Functional Connectivity Associated With Pornography Consumption: The Brain on Porn (2014) - A German study which found 3 significant addiction-related brain changes that correlated with the amount of porn consumed. It also found that the more porn consumed the less activity in the reward circuit, indicating desensitization, and increasing the need for greater stimulation (tolerance).
  2. Neural Correlates of Sexual Cue Reactivity in Individuals with and without Compulsive Sexual Behaviours (2014) - The first in a series of studies. It found the same brain activity as seen in drug addicts and alcoholics. It also found that porn addicts fit the accepted addiction model of wanting "it" more, but not liking "it" more. One other major finding (not reported in the media), was that over 50% of subjects (average age: 25) had difficulty achieving erections/arousal with real partners, yet could achieve erections with porn.
  3. Enhanced Attentional Bias towards Sexually Explicit Cues in Individuals with and without Compulsive Sexual Behaviours (2014) - Findings match those seen in drug addiction.
  4. Novelty, Conditioning and Attentional Bias to Sexual Rewards (2015) - Compared to controls porn addicts preferred sexual novelty and conditioned cues associated porn. However, the brains of porn addicts habituated faster to sexual images. Since novelty preference wasn't pre-existing, porn addiction drives novelty-seeking in an attempt to overcome habituation and desensitization.
  5. Neural Substrates of Sexual Desire in Individuals with Problematic Hypersexual Behavior (2015) - This Korean fMRI study replicates other brain studies on porn users. Like the Cambridge University studies it found cue-induced brain activation patterns in sex addicts which mirrored the patterns of drug addicts. In line with several German studies it found alterations in the prefrontal cortex which match the changes observed in drug addicts.
  6. 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. This SPAN Lab study, like #5 below, actually supports the existence of porn addiction. Why? The study reported higher EEG readings (P300) when subjects were exposed to porn photos. Studies consistently show that an elevated P300 occurs when addicts are exposed to cues (such as images) related to their addiction. However, the study had no control group for comparison, which made the findings uninterpretable. In line with the Cambridge studies, this EEG study reported greater cue-reactivity to porn correlated with less desire for partnered sex. Neither finding matched the headlines. Read more.
  7. Modulation of Late Positive Potentials by Sexual Images in Problem Users and Controls Inconsistent with "Porn Addiction" (2015) - Another SPAN Lab EEG study comparing the 2013 subjects from the above study to an actual control group. The results: compared to controls porn addicts had less response to photos of vanilla porn. The lead author, Nicole Prause, claims these results debunk porn addiction, yet 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 needed greater stimulation than non-addicts. Read more.
  8. HPA axis dysregulation in men with hypersexual disorder (2015) - The Hypothalamus-Pituitary-Adrenal (HPA) axis is the central player in our stress response. Addictions alter the brain's stress circuits leading to a dysfunctional HPA axis. This study on sex addicts (hypersexuals) found altered stress responses that mirror drug addiction.
  9. The Role of Neuroinflammation in the Pathophysiology of Hypersexual Disorder (2016) - This study reported higher levels of circulating Tumor Necrosis Factor (TNF) in sex addicts when compared to healthy controls. Elevated levels of TNF (a marker of inflammation) have also been found in substance abusers and drug addicted animals (alcohol, heroin, meth).
  10. Methylation of HPA Axis Related Genes in Men With Hypersexual Disorder (2017) - This is a follow-up of #8 above which found that sex addicts have dysfunctional stress systems - a key neuro-endocrine change caused by addiction. The current study found epigenetic changes on genes central to the human stress response and closely associated with addiction.
  11. Compulsive sexual behavior: Prefrontal and limbic volume and interactions (2016) - Compared to healthy controls CSB subjects (porn addicts) had increased left amygdala volume and reduced functional connectivity between the amygdala and dorsolateral prefrontal cortex DLPFC.
  12. Ventral striatum activity when watching preferred pornographic pictures is correlated with symptoms of Internet pornography addiction (2016) - Finding #1: Reward center activity (ventral striatum) was higher for preferred pornographic pictures. Finding #2: Ventral striatum reactivity correlated with the internet sex addiction score. Both findings indicate sensitization and align with the addiction model. The authors state that the "Neural basis of Internet pornography addiction is comparable to other addictions."
  13. Altered Appetitive Conditioning and Neural Connectivity in Subjects With Compulsive Sexual Behavior (2016) - A German fMRI study replicating two major findings from Voon et al., 2014 and Kuhn & Gallinat 2014. Compared to controls compulsive porn users had 1) greater conditioned cue-induced activity in the amygdala, while having 2) decreased coupling between the ventral striatum and the prefrontal cortex. Number 1 indicates sensitization, while number 2 indicates hypofronatlity. In addition, 3 of the 20 compulsive porn users suffered from "orgasmic-erection disorder".
  14. Preliminary investigation of the impulsive and neuroanatomical characteristics of compulsive sexual behavior (2009) - Primarily sex addicts. Study reports more impulsive behavior in a Go-NoGo task in sex addicts (hypersexuals) compared to control participants. Brain scans revealed that sex addicts had greater disorganized prefrontal cortex white matter. This finding is consistent with hypofrontality, a hallmark of addiction.
  15. Conscious and Non-Conscious Measures of Emotion: Do They Vary with Frequency of Pornography Use? (2017) – An excerpt: Findings suggest that increased pornography use appears to have an influence on the brain’s non-conscious responses to emotion-inducing stimuli which was not shown by explicit self-report.
  16. Can Pornography be Addictive? An fMRI Study of Men Seeking Treatment for Problematic Pornography Use (2017) - Excerpts: Our findings suggest that, similar to what is observed in substance and gambling addictions, the neural and behavioral mechanisms associated with the anticipatory processing of cues specifically predicting erotic rewards relate importantly to clinically relevant features of problematic pornography use (PPU)
  17. Compulsivity across the pathological misuse of drug and non-drug rewards (2016) - A Cambridge University study comparing aspects of compulsivity in alcoholics, binge-eaters, video game addicts and porn addicts (CSB). Excerpts: CSB subjects were faster to learning from rewards in the acquisition phase compared to healthy volunteers and were more likely to perseverate or stay after either a loss or a win in the Reward condition.

Together these brain studies found:

  1. The 3 major addiction-related brain changes: sensitization, desensitization, and hypofrontality.
  2. More porn use correlated with less grey matter in the reward circuit (dorsal striatum).
  3. More porn use correlated with less reward circuit activation when briefly viewing sexual images.
  4. More porn use correlated with disrupted neural connections between the reward circuit and prefrontal cortex.
  5. Addicts had greater prefrontal activity to sexual cues, but less brain activity to normal stimuli (matches drug addiction).
  6. Porn addicts have greater preference for sexual novelty yet their brains habituated faster to sexual images. Not pre-existing.
  7. 60% of compulsive porn addicted subjects in one study experienced ED or low libido with partners, but not with porn: all stated that internet porn use caused their ED/low libido.
  8. Enhanced attentional bias comparable to drug users. Indicates sensitization (a product of DeltaFosb accumulation).
  9. Greater wanting & craving for porn, but not greater liking. This aligns with the accepted model of addiction - incentive sensitization.
  10. The younger the porn users the greater the cue-induced reactivity in the reward center.
  11. Higher EEG (P300) readings when porn users were exposed to porn cues (which occurs in other addictions).
  12. Less desire for sex with a person correlating with greater cue-reactivity to porn images.
  13. More porn use correlated with lower LPP amplitude when briefly viewing sexual photos: indicates habituation or desensitization.
  14. Dysfunctional HPA axis which reflects altered brain stress circuits, which occurs in drug addictions (and greater amygdala volume, which is associated with chronic social stress).
  15. Epigenetic changes on genes central to the human stress response and closely associated with addiction.
  16. Higher circulating levels of Tumor Necrosis Factor (TNF) which also occurs in drug abuse and addiction.

The following neuropsychology studies add support to the above neurological studies:

  1. Watching Pornographic Pictures on the Internet: Role of Sexual Arousal Ratings and Psychological-Psychiatric Symptoms for Using Internet Sex Sites Excessively (2011)
  2. Enhanced Attentional Bias towards Sexually Explicit Cues in Individuals with and without Compulsive Sexual Behaviours (2014)
  3. Pornographic picture processing interferes with working memory performance (2013)
  4. Sexual Picture Processing Interferes with Decision-Making Under Ambiguity (2013)
  5. Cybersex addiction: Experienced sexual arousal when watching pornography and not real-life sexual contacts makes the difference (2013)
  6. Cybersex addiction in heterosexual female users of internet pornography can be explained by gratification hypothesis (2014)
  7. Empirical Evidence and Theoretical Considerations on Factors Contributing to Cybersex Addiction From a Cognitive Behavioral View (2014)
  8. Implicit associations in cybersex addiction: Adaption of an Implicit Association Test with pornographic pictures. (2015)
  9. Symptoms of cybersex addiction can be linked to both approaching and avoiding pornographic stimuli: results from an analog sample of regular cybersex users (2015)
  10. Getting stuck with pornography? Overuse or neglect of cybersex cues in a multitasking situation is related to symptoms of cybersex addiction (2015)
  11. Sexual Excitability and Dysfunctional Coping Determine Cybersex Addiction in Homosexual Males (2015)
  12. Trading Later Rewards for Current Pleasure: Pornography Consumption and Delay Discounting (2015)
  13. Subjective Craving for Pornography and Associative Learning Predict Tendencies Towards Cybersex Addiction in a Sample of Regular Cybersex Users (2016)
  14. Exploring the Relationship between Sexual Compulsivity and Attentional Bias to Sex-Related Words in a Cohort of Sexually Active Individuals (2016)
  15. Mood changes after watching pornography on the Internet are linked to symptoms of Internet-pornography-viewing disorder (2016)
  16. Problematic sexual behavior in young adults: Associations across clinical, behavioral, and neurocognitive variables (2016)
  17. Executive Functioning of Sexually Compulsive and Non-Sexually Compulsive Men Before and After Watching an Erotic Video (2017)

Prior to the above studies YBOP claimed that internet porn addiction was real and caused the same fundamental brain changes as seen in other addictions. We were confident in this claim because basic physiology rests on the fact that drugs do not create anything new or different; they simply increase or decrease normal brain functions. We already possess the machinery for addiction (mammalian mating/bonding/love circuitry), and for binging (storing calories, mating season). Moreover, years of addiction research have clearly demonstrated that addiction is a single condition, reflected in a typical constellation of signs, symptoms and behaviors (Natural Rewards, Neuroplasticity, and Non-Drug Addictions (2011).

These studies on Internet porn users should come as no surprise because some 200 brain studies had already confirmed that "Internet addicts" develop the same major addiction-related brain changes that occur in all addictions. Many more assessment-based Internet addiction studies back up what the brain studies found. Internet porn, internet gaming, and social media are now being viewed as separate applications or subcategories of Internet use. An individual can be addicted to Facebook or Internet porn, while not having a "generalized Internet addiction". A 2006 Dutch study found that erotica had the highest addictive potential of all Internet applications.

No wonder. Internet erotica is an extreme version of natural rewards that we're all wired to pursue: sexual arousal and apparent mating opportunities. Today's extreme porn is as unnatural a "natural reinforcer" as today's junk food is. See our article Porn Then and Now: Welcome to Brain Training, and this excellent peer-reviewed article, with a current review of where neuroscience is with respect to Internet porn addiction: Pornography addiction – a supranormal stimulus considered in the context of neuroplasticity (2013).

Recent research on brain changes in response to "highly palatable foods" is revealing evidence of an addiction process. If gambling, gaming, Internet use and food can alter the brain in this way, it would have been amazing to believe that Internet porn alone could not. This is why In 2011, 3000 doctors of the American Society for Addiction Medicine (ASAM) came out with a public statement clarifying that behavioral addictions (sexual, food, gambling) are fundamentally like substance addictions in terms of brain changes. Said ASAM:

"We all have the brain reward circuitry that makes food and sex rewarding. In fact, this is a survival mechanism. In a healthy brain, these rewards have feedback mechanisms for satiety or ‘enough.’ In someone with addiction, the circuitry becomes dysfunctional such that the message to the individual becomes ‘more’, which leads to the pathological pursuit of rewards and/or relief through the use of substances and behaviors."

In its faq's ASAM specifically addresed sexual behavior addictions:

QUESTION: This new definition of addiction refers to addiction involving gambling, food, and sexual behaviours. Does ASAM really believe that food and sex are addicting?

ANSWER: The new ASAM definition makes a departure from equating addiction with just substance dependence, by describing how addiction is also related to behaviours that are rewarding. ... This definition says that addiction is about functioning and brain circuitry and how the structure and function of the brains of persons with addiction differ from the structure and function of the brains of persons who do not have addiction. ... Food and sexual behaviours and gambling behaviours can be associated with the "pathological pursuit of rewards" described in this new definition of addiction.

In light of the latest scientific advances, the criticisms of the sexual-behavior addiction model are unfounded and outdated.