There are no scientific studies that say porn is addictive, right?

This FAQ is now obsolete as the world’s most widely used medical diagnostic manual, The International Classification of Diseases (ICD-11), contains a new diagnosis suitable for porn addiction and cybersex addiction: “Compulsive Sexual Behavior Disorder.” The current state of the scientific research supports the existence of porn addiction and porn-induced sexual dysfunctions. For example, a few lists:

1.  This page lists 55 neuroscience-based studies (MRI, fMRI, EEG, neuropsychological, hormonal). They provide strong support for the addiction model as their findings mirror the neurological findings reported in substance addiction studies.
2. The real experts’ opinions on porn/sex addiction? This list contains 31 recent literature reviews & commentaries by some of the top neuroscientists in the world. All support the addiction model.
3. Over 55 studies reporting findings consistent with escalation of porn use (tolerance), habituation to porn, and even withdrawal symptoms (all signs and symptoms associated with addiction).
4. Debunking the unsupported talking point that “high sexual desire” explains away porn or sex addiction: At least 25 studies falsify the claim that sex & porn addicts “just have high sexual desire”
5. Porn and sexual problems? This list contains over 40 studies linking porn use/porn addiction to sexual problems and lower arousal to sexual stimuli. The first 7 studies in the list demonstrate causation, as participants eliminated porn use and healed chronic sexual dysfunctions.
6. Porn’s effects on relationships? Over 75 studies link porn use to less sexual and relationship satisfaction. As far as we know all studies involving males have reported more porn use linked to poorer sexual or relationship satisfaction.
7. Porn use affecting emotional and mental health? Over 85 studies link porn use to poorer mental-emotional health & poorer cognitive outcomes.
8. Porn use affecting beliefs, attitudes and behaviors? Check out individual studies – over 40 studies link porn use to “un-egalitarian attitudes” toward women and sexist views – or the summary from this 2016 meta-analysis: Media and Sexualization: State of Empirical Research, 1995–2015. Excerpt:

The goal of this review was to synthesize empirical investigations testing effects of media sexualization. The focus was on research published in peer-reviewed, English-language journals between 1995 and 2015. A total of 109 publications that contained 135 studies were reviewed. The findings provided consistent evidence that both laboratory exposure and regular, everyday exposure to this content are directly associated with a range of consequences, including higher levels of body dissatisfaction, greater self-objectification, greater support of sexist beliefs and of adversarial sexual beliefs, and greater tolerance of sexual violence toward women. Moreover, experimental exposure to this content leads both women and men to have a diminished view of women’s competence, morality, and humanity.

10. What about sexual aggression and porn use? Another meta-analysis: A Meta‐Analysis of Pornography Consumption and Actual Acts of Sexual Aggression in General Population Studies (2015). Excerpt:

22 studies from 7 different countries were analyzed. Consumption was associated with sexual aggression in the United States and internationally, among males and females, and in cross-sectional and longitudinal studies. Associations were stronger for verbal than physical sexual aggression, although both were significant. The general pattern of results suggested that violent content may be an exacerbating factor.

“But hasn’t porn use reduced rape rates?” No, rape rates have been rising in recent years: “Rape rates are on the rise, so ignore the pro-porn propaganda.” See this page for over 100 studies linking porn use to sexual aggression, coercion & violence, and an extensive critique of the often-repeated assertion that an increased availability of porn has resulted in decreased rape rates.

11. What about the porn use and adolescents? Check out this list of over 270 adolescent studies, or these reviews of the literature: review#1, review2, review#3, review#4, review#5, review#6, review#7, review#8, review#9, review#10, review#11, review#12, review#13, review#14, review#15. From the conclusion of this 2012 review of the research – The Impact of Internet Pornography on Adolescents: A Review of the Research:

Increased access to the Internet by adolescents has created unprecedented opportunities for sexual education, learning, and growth. Conversely, the risk of harm that is evident in the literature has led researchers to investigate adolescent exposure to online pornography in an effort to elucidate these relationships. Collectively, these studies suggest that youth who consume pornography may develop unrealistic sexual values and beliefs. Among the findings, higher levels of permissive sexual attitudes, sexual preoccupation, and earlier sexual experimentation have been correlated with more frequent consumption of pornography…. Nevertheless, consistent findings have emerged linking adolescent use of pornography that depicts violence with increased degrees of sexually aggressive behavior.

The literature does indicate some correlation between adolescents’ use of pornography and self-concept. Girls report feeling physically inferior to the women they view in pornographic material, while boys fear they may not be as virile or able to perform as the men in these media. Adolescents also report that their use of pornography decreased as their self-confidence and social development increase. Additionally, research suggests that adolescents who use pornography, especially that found on the Internet, have lower degrees of social integration, increases in conduct problems, higher levels of delinquent behavior, higher incidence of depressive symptoms, and decreased emotional bonding with caregivers.

12. Aren’t all studies correlative? Nope: Over 90 Studies demonstrating internet use & porn use causing negative outcomes & symptoms, and brain changes.

Want to see papers that bear on internet porn’s addictiveness? Here are recent neuroscience-based reviews of the literature, which focus on research on porn users:

1. 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.
2. 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.
3. Neurobiology of Compulsive Sexual Behavior: Emerging Science (2016) Excerpt: “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.”
4. Should Compulsive Sexual Behavior be Considered an Addiction? (2016) Excerpt: “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. Similar pharmacological and psychotherapeutic treatments may be applicable to CSB and substance addictions”
5. 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.“
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. 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.
8. 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.
9. 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.
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.
12. 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.
13. Is excessive sexual behaviour an addictive disorder? (2017) – Excerpts: Research into the neurobiology of compulsive sexual behaviour disorder has generated findings relating to attentional biases, incentive salience attributions, and brain-based cue reactivity that suggest substantial similarities with addictions. We believe that classification of compulsive sexual behaviour disorder as an addictive disorder is consistent with recent data and might benefit clinicians, researchers, and individuals suffering from and personally affected by this disorder.
14. The Proof of the Pudding Is in the Tasting: Data Are Needed to Test Models and Hypotheses Related to Compulsive Sexual Behaviors (2018) – Excerpts: Among the domains that may suggest similarities between CSB and addictive disorders are neuroimaging studies, with several recent studies omitted by Walton et al. (2017). Initial studies often examined CSB with respect to models of addiction (reviewed in Gola, Wordecha, Marchewka, & Sescousse, 2016b; Kraus, Voon, & Potenza, 2016b).
15. Promoting educational, classification, treatment, and policy initiatives Commentary on: Compulsive sexual behaviour disorder in the ICD-11 (Kraus et al., 2018) – Excerpts: The current proposal of classifying CSB disorder as an impulse-control disorder is controversial as alternate models have been proposed (Kor, Fogel, Reid, & Potenza, 2013). There are data suggesting that CSB shares many features with addictions (Kraus et al., 2016), including recent data indicating increased reactivity of reward-related brain regions in response to cues associated with erotic stimuli (Brand, Snagowski, Laier, & Maderwald, 2016; Gola, Wordecha, Marchewka, & Sescousse, 2016; Gola et al., 2017; Klucken, Wehrum-Osinsky, Schweckendiek, Kruse, & Stark, 2016; Voon et al., 2014.
16. Compulsive Sexual Behavior in Humans and Preclinical Models (2018) – Excerpts: Compulsive sexual behavior (CSB) is widely regarded as a “behavioral addiction,” and is a major threat to quality of life and both physical and mental health. In conclusion, this review summarized the behavioral and neuroimaging studies on human CSB and comorbidity with other disorders, including substance abuse. Together, these studies indicate that CSB is associated with functional alterations in dorsal anterior cingulate and prefrontal cortex, amygdala, striatum, and thalamus, in addition to decreased connectivity between amygdala and prefrontal cortex.
17. Sexual Dysfunctions in the Internet Era (2018) – Excerpt: Among behavioral addictions, problematic Internet use and online pornography consumption are often cited as possible risk factors for sexual dysfunction, often with no definite boundary between the two phenomena. Online users are attracted to Internet pornography because of its anonymity, affordability, and accessibility, and in many cases its usage could lead users through a cybersex addiction: in these cases, users are more likely to forget the “evolutionary” role of sex, finding more excitement in self-selected sexually explicit material than in intercourse.
18. Neurocognitive mechanisms in compulsive sexual behavior disorder (2018) – Excerpt: To date, most neuroimaging research on compulsive sexual behavior has provided evidence of overlapping mechanisms underlying compulsive sexual behavior and non-sexual addictions. Compulsive sexual behavior is associated with altered functioning in brain regions and networks implicated in sensitization, habituation, impulse dyscontrol, and reward processing in patterns like substance, gambling, and gaming addictions. Key brain regions linked to CSB features include the frontal and temporal cortices, amygdala, and striatum, including the nucleus accumbens.
19. A Current Understanding of the Behavioral Neuroscience of Compulsive Sexual Behavior Disorder and Problematic Pornography Use – Excerpt: Recent neurobiological studies have revealed that compulsive sexual behaviors are associated with altered processing of sexual material and differences in brain structure and function. Although few neurobiological studies of CSBD have been conducted to date, existing data suggest neurobiological abnormalities share communalities with other additions such as substance use and gambling disorders. Thus, existing data suggest that its classification may be better suited as a behavioral addiction rather than an impulse-control disorder.
20. Ventral Striatal Reactivity in Compulsive Sexual Behaviors (2018) – Excerpt: Among currently available studies, we were able to find nine publications (Table 1) which utilized functional magnetic resonance imaging. Only four of these (36–39) directly investigated processing of erotic cues and/or rewards and reported findings related to ventral striatum activations. Three studies indicate increased ventral striatal reactivity for erotic stimuli (36–39) or cues predicting such stimuli (36–39). These findings are consistent with Incentive Salience Theory (IST) (28), one of the most prominent frameworks describing brain functioning in addiction.
21. Online Porn Addiction: What We Know and What We Don’t—A Systematic Review (2019) – Excerpt: As far as we know, a number of recent studies support this entity as an addiction with important clinical manifestations such as sexual dysfunction and psychosexual dissatisfaction. Most of the existing work is based off on similar research done on substance addicts, based on the hypothesis of online pornography as a ‘supranormal stimulus’ akin to an actual substance that, through continued consumption, can spark an addictive disorder.
22. Occurrence and development of online porn addiction: individual susceptibility factors, strengthening mechanisms and neural mechanisms (2019) – Excerpt: The long-term experience of online pornography has led to the sensitization of such people to online pornography-related clues, which has led to a growing sense of craving, compulsive use of online pornography under the dual factors of temptation and functional impairment. The sense of satisfaction gained from it is getting weaker and weaker, so more and more online pornography is needed to maintain the previous emotional state and become addicted.
23. Theories, prevention, and treatment of pornography-use disorder (2019) – Excerpt: Compulsive sexual behavior disorder, including problematic pornography use, has been included in the ICD-11 as impulse control disorder. The diagnostic criteria for this disorder, however, are very similar to the criteria for disorders due to addictive behaviors… Theoretical considerations and empirical evidence suggest that the psychological and neurobiological mechanisms involved in addictive disorders are also valid for pornography-use disorder.
24. Self-perceived Problematic Pornography Use: An Integrative Model from a Research Domain Criteria and Ecological Perspective (2019) – Excerpt: Self-perceived problematic pornography use seems to be related to multiple units of analysis and different systems in the organism. Based on the findings within the RDoC paradigm described above, it is possible to create a cohesive model in which different units of analysis impact each other (Fig. 1). These changes in internal and behavioral mechanisms among people with SPPPU are similar to those observed in people with substance addictions, and map into models of addiction.
25. Cybersex addiction: an overview of the development and treatment of a newly emerging disorder (2020) – Excerpts: Cybersex addiction is a non-substance related addiction that involves online sexual activity on the internet. Nowadays, various kinds of things related to sex or pornography are easily accessible through internet media. In Indonesia, sexuality is usually assumed taboo but most young people have been exposed to pornography. It can lead to an addiction with many negative effects on users, such as relationships, money, and psychiatric problems like major depression and anxiety disorders.
26. Which Conditions Should Be Considered as Disorders in the International Classification of Diseases (ICD-11) Designation of “Other Specified Disorders Due to Addictive Behaviors”? (2020) – Excerpts: Data from self-report, behavioral, electrophysiological, and neuroimaging studies demonstrate an involvement of psychological processes and underlying neural correlates that have been investigated and established to varying degrees for substance-use disorders and gambling/gaming disorders (criterion 3). Commonalities noted in prior studies include cue-reactivity and craving accompanied by increased activity in reward-related brain areas, attentional biases, disadvantageous decision-making, and (stimuli-specific) inhibitory control.
27. The Addictive Nature of Compulsive Sexual Behaviours and Problematic Online Pornography Consumption: A Review – Excerpts: Available findings suggest that there are several features of CSBD and POPU that are consistent with characteristics of addiction, and that interventions helpful in targeting behavioural and substance addictions warrant consideration for adaptation and use in supporting individuals with CSBD and POPU….  The neurobiology of POPU and CSBD involves a number of shared neuroanatomical correlates with established substance use disorders, similar neuropsychological mechanisms, as well as common neurophysiological alterations in the dopamine reward system.
28. Dysfunctional sexual behaviors: definition, clinical contexts, neurobiological profiles and treatments (2020) – Excerpts: Porn addiction, although distinct neurobiologically from sexual addiction, is still a form of behavioral addiction….The sudden suspension of porn addiction causes negative effects in mood, excitement, and relational and sexual satisfaction….The massive use of pornography facilitates the onset of psychosocial disorders and relationship difficulties…
29. What should be included in the criteria for compulsive sexual behavior disorder? (2020) – Excerpts: The classification of CSBD as an impulse control disorder also warrants consideration. … Additional research may help refine the most appropriate classification of CSBD as happened with gambling disorder, reclassified from the category of impulse control disorders to non-substance or behavioral addictions in DSM-5 and ICD-11. … impulsivity may not contribute as strongly to problematic pornography use as some have proposed (Bőthe et al., 2019).
30. Decision-Making in Gambling Disorder, Problematic Pornography Use, and Binge-Eating Disorder: Similarities and Differences (2021) – Excerpts: Similarities between CSBD and addictions have been described, and impaired control, persistent use despite adverse consequences, and tendencies to engage in risky decisions may be shared features (37••, 40). Individuals with these disorders often show impaired cognitive control and disadvantageous decision-making [12, 15,16,17]. Deficits in decision-making processes and goal-directed learning have been found across multiple disorders.

See Questionable & Misleading Studies for highly publicized papers that are not what they claim to be.

Recent studies assessing brain structure & functioning of Internet porn users:

1. Brain Structure and Functional Connectivity Associated With Pornography Consumption: The Brain on Porn (2014) – A German fMRI study which found 3 significant addiction-related brain changes correlating with the amount of porn consumed. It also found that more porn use correlated with less reward circuit activation while viewing sexual photos. Researchers stated their findings indicated desensitization, and possibly tolerance, the need for greater stimulation.
2. Neural Correlates of Sexual Cue Reactivity in Individuals with and without Compulsive Sexual Behaviours (2014) – The first in a series of Cambridge University studies 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. The researchers also reported that 60% 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) – The second Cambridge University study. An excerpt: “Our findings of enhanced attentional bias… suggest possible overlaps with enhanced attentional bias observed in studies of drug cues in disorders of addictions. These findings converge with recent findings of neural reactivity to sexually explicit cues in [porn addicts] in a network similar to that implicated in drug-cue-reactivity studies and provide support for incentive motivation theories of addiction underlying the aberrant response to sexual cues in [porn addicts].“
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/sex addiction. Not so. Steele et al. 2013 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. 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 it 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 (subjects’ desire for partnered sex was dropping in relation to their porn use). Together these two Steele et al. findings indicate greater brain activity to cues (porn images), yet less reactivity to natural rewards (sex with a person). That”s sensitization & desensitization, which are hallmarks of an addiction. Seven peer-reviewed papers explain the truth: 1, 2, 3, 4, 5, 6, 7. Also see this extensive YBOP critique. Aside from the many unsupported claims in the press, it’s disturbing that Prause’s 2013 EGG study passed peer-review, as it suffered from serious methodological flaws: 1) subjects were heterogeneous (males, females, non-heterosexuals); 2) subjects were not screened for mental disorders or addictions; 3) study had no control group for comparison; 4) questionnaires were not validated for porn use or porn addiction. Steele at al. is so badly flawed that only 4 of the above 20 literature reviews & commentaries bother to mention it: two critiquing it as unacceptable junk science, while two cite it as correlating cue-reactivity with less desire for sex with a partner (signs of addiction).
7. Modulation of Late Positive Potentials by Sexual Images in Problem Users and Controls Inconsistent with “Porn Addiction” (2015) – A second EEG study from Nicole Prause’s team. This study compared the 2013 subjects from Steele et al., 2013 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 claims these results “debunk porn addiction.” What legitimate scientist would claim that their lone anomalous study has debunked a well established 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 et al. findings also align with Banca et al. 2015 which is #13 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. Eight peer-reviewed papers agree that this study actually found desensitization/habituation in frequent porn users (consistent with addiction): 1, 2, 3, 4, 5, 6, 7, 8. Prause proclaimed that her EEG readings assessed “cue-reactivity” (sensitization), rather than habituation. Even if Prause were correct she conveniently ignores the gaping hole in her “falsification” assertion: Even if Prause et al. 2015 had found less cue-reactivity in frequent porn users, 21 other neurological studies have reported cue-reactivity or cravings (sensitization) in compulsive porn users: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21. Science doesn’t go with the lone anomalous study hampered by serious methodological flaws; science goes with the preponderance of evidence (unless you are agenda-driven).
8. HPA Axis Dysregulation in Men With Hypersexual Disorder (2015) – A study with 67 male sex addicts and 39 age-matched controls. 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 the findings with substance addictions.
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). There were strong correlations between TNF levels and rating scales measuring hypersexuality.
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. With epigenetic changes, the DNA sequence isn’t altered (as happens with a mutation). Instead, the gene is tagged and its expression is turned up or down (short video explaining epigenetics). The epigenetic changes reported in this study resulted in altered CRF gene activity. CRF is a neurotransmitter and hormone that drives addictive behaviors such as cravings, and is a major player in many of the withdrawal symptoms experienced in connection with substance and behavioral addictions, including porn 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. Reduced functional connectivity between the amygdala and the prefrontal cortex aligns with substance addictions. It is thought that poorer connectivity diminishes the prefrontal cortex’s control over a user’s impulse to engage in the addictive behavior. This study suggests that drug toxicity may lead to less gray matter and thus reduced amygdala volume in drug addicts. The amygdala is consistently active during porn viewing, especially during initial exposure to a sexual cue. Perhaps the constant sexual novelty and searching and seeking leads to a unique effect on the amygdala in compulsive porn users. Alternatively, years of porn addiction and severe negative consequences is very stressful – and chronic social stress is related to increased amygdala volume. Study #8 above found that “sex addicts” have a overactive stress system. Could the chronic stress related to porn/sex addiction, along with factors that make sex unique, lead to greater amygdala volume?
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. Main Findings: The neural correlates of appetitive conditioning and neural connectivity were altered in the CSB group. According to the researchers, the first alteration – heightened amygdala activation – might reflect facilitated conditioning (greater “wiring” to previously neutral cues predicting porn images). The second alteration – decreased connectivity between the ventral striatum and the prefrontal cortex – could be a marker for impaired ability to control impulses. Said the researchers, “These [alterations] are in line with other studies investigating the neural correlates of addiction disorders and impulse control deficits.” The findings of greater amygdalar activation to cues (sensitization) and decreased connectivity between the reward center and the prefrontal cortex (hypofrontality) are two of the major brain changes seen in substance addiction. In addition, 3 of the 20 compulsive porn users suffered from “orgasmic-erection disorder”
14. 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. These findings converge with our previous findings of enhanced preference for stimuli conditioned to either sexual or monetary outcomes, overall suggesting enhanced sensitivity to rewards (Banca et al., 2016).
15. Can Pornography be Addictive? An fMRI Study of Men Seeking Treatment for Problematic Pornography Use (2017) – Excerpts: Men with and without problematic porn use (PPU) differed in brain reactions to cues predicting erotic pictures, but not in reactions to erotic pictures themselves, consistent with the incentive salience theory of addictions. This brain activation was accompanied by increased behavioral motivation to view erotic images (higher ‘wanting’). Ventral striatal reactivity for cues predicting erotic pictures was significantly related to the severity of PPU, amount of pornography use per week and number of weekly masturbations. Our findings suggest that like in substance-use and gambling disorders the neural and behavioral mechanisms linked to anticipatory processing of cues relate importantly to clinically relevant features of PPU. These findings suggest that PPU may represent a behavioral addiction and that interventions helpful in targeting behavioral and substance addictions warrant consideration for adaptation and use in helping men with PPU.
16. Conscious and Non-Conscious Measures of Emotion: Do They Vary with Frequency of Pornography Use? (2017) – Study assessed porn user’s responses (EEG readings & Startle Response) to various emotion-inducing images – including erotica. The study found several neurological  differences between low frequency porn users and high frequency porn users. 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.
17. 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.
18. Self-reported differences on measures of executive function and hypersexual behavior in a patient and community sample of men (2010) – Patients seeking help for hypersexual behavior often exhibit features of impulsivity, cognitive rigidity, poor judgment, deficits in emotion regulation, and excessive preoccupation with sex. Some of these characteristics are also common among patients presenting with neurological pathology associated with executive dysfunction. These observations led to the current investigation of differences between a group of hypersexual patients (n = 87) and a non-hypersexual community sample (n = 92) of men using the Behavior Rating Inventory of Executive Function-Adult Version  Hypersexual behavior was positively correlated with global indices of executive dysfunction and several subscales of the BRIEF-A. These findings provide preliminary evidence supporting the hypothesis that executive dysfunction may be implicated in hypersexual behavior.
19. Watching Pornographic Pictures on the Internet: Role of Sexual Arousal Ratings and Psychological-Psychiatric Symptoms for Using Internet Sex Sites Excessively (2011) – Results indicate that self-reported problems in daily life linked to online sexual activities were predicted by subjective sexual arousal ratings of the pornographic material, global severity of psychological symptoms, and the number of sex applications used when being on Internet sex sites in daily life, while the time spent on Internet sex sites (minutes per day) did not significantly contribute to explanation of variance in IATsex score. We see some parallels between cognitive and brain mechanisms potentially contributing to the maintenance of excessive cybersex and those described for individuals with substance dependence
20. Pornographic picture processing interferes with working memory performance (2013) – Some individuals report problems during and after Internet sex engagement, such as missing sleep and forgetting appointments, which are associated with negative life consequences. One mechanism potentially leading to these kinds of problems is that sexual arousal during Internet sex might interfere with working memory (WM) capacity, resulting in a neglect of relevant environmental information and therefore disadvantageous decision making. Results revealed worse WM performance in the pornographic picture condition of the 4-back task compared with the three remaining picture conditions. Findings are discussed with respect to Internet addiction because WM interference by addiction-related cues is well known from substance dependencies.
21. Sexual Picture Processing Interferes with Decision-Making Under Ambiguity (2013) – Decision-making performance was worse when sexual pictures were associated with disadvantageous card decks compared to performance when the sexual pictures were linked to the advantageous decks. Subjective sexual arousal moderated the relationship between task condition and decision-making performance. This study emphasized that sexual arousal interfered with decision-making, which may explain why some individuals experience negative consequences in the context of cybersex use.
22. Cybersex addiction: Experienced sexual arousal when watching pornography and not real-life sexual contacts makes the difference (2013) – The results show that indicators of sexual arousal and craving to Internet pornographic cues predicted tendencies towards cybersex addiction in the first study. Moreover, it was shown that problematic cybersex users report greater sexual arousal and craving reactions resulting from pornographic cue presentation. In both studies, the number and the quality with real-life sexual contacts were not associated to cybersex addiction. The results support the gratification hypothesis, which assumes reinforcement, learning mechanisms, and craving to be relevant processes in the development and maintenance of cybersex addiction. Poor or unsatisfying sexual real life contacts cannot sufficiently explain cybersex addiction.
23. Empirical Evidence and Theoretical Considerations on Factors Contributing to Cybersex Addiction From a Cognitive-Behavioral View (2014) – Dysfunctional use of sex mediated the relationship of sexual excitability with cybersex addiction (CA). The results of the study show that there are factors of vulnerability to CA and provide evidence for the role of sexual gratification and dysfunctional coping in the development of cybersex addiction.
24. Cybersex addiction in heterosexual female users of internet pornography can be explained by gratification hypothesis (2014) – Results indicated that Internet porn users rated pornographic pictures as more arousing and reported greater craving due to pornographic picture presentation compared with non-users. Moreover, craving, sexual arousal rating of pictures, sensitivity to sexual excitation, problematic sexual behavior, and severity of psychological symptoms predicted tendencies toward cybersex addiction in porn users. Being in a relationship, number of sexual contacts, satisfaction with sexual contacts, and use of interactive cybersex were not associated with cybersex addiction.
25. Prefrontal control and internet addiction: a theoretical model and review of neuropsychological and neuroimaging findings (2015) – Consistent with this, results from functional neuroimaging and other neuropsychological studies demonstrate that cue-reactivity, craving, and decision making are important concepts for understanding Internet addiction. The findings on reductions in executive control are consistent with other behavioral addictions, such as pathological gambling. They also emphasize the classification of the phenomenon as an addiction, because there are also several similarities with findings in substance dependency.  Moreover, the results of the current study are comparable to findings from substance dependency research and emphasize analogies between cybersex addiction and substance dependencies or other behavioral addictions.
26. Implicit associations in cybersex addiction: Adaption of an Implicit Association Test with pornographic pictures. (2015) – Recent studies show similarities between cybersex addiction and substance dependencies and argue to classify cybersex addiction as a behavioral addiction. In substance dependency, implicit associations are known to play a crucial role. Results show positive relationships between implicit associations of pornographic pictures with positive emotions and tendencies towards cybersex addiction, problematic sexual behavior, sensitivity towards sexual excitation as well as subjective craving.
27. Symptoms of cybersex addiction can be linked to both approaching and avoiding pornographic stimuli: results from an analog sample of regular cybersex users (2015) – Results showed that individuals with tendencies toward cybersex addiction tended to either approach or avoid pornographic stimuli. Additionally, moderated regression analyses revealed that individuals with high sexual excitation and problematic sexual behavior who showed high approach/avoidance tendencies, reported higher symptoms of cybersex addiction. Analogous to substance dependencies, results suggest that both approach and avoidance tendencies might play a role in cybersex addiction.
28. Getting stuck with pornography? Overuse or neglect of cybersex cues in a multitasking situation is related to symptoms of cybersex addiction (2015) – Individuals with tendencies towards cybersex addiction seem to have either an inclination to avoid or to approach the pornographic material, as discussed in motivational models of addiction. The results of the current study point towards a role of executive control functions, i.e. functions mediated by the prefrontal cortex, for the development and maintenance of problematic cybersex use (as suggested by Brand et al., 2014). Particularly a reduced ability to monitor consumption and to switch between pornographic material and other contents in a goal adequate manner may be one mechanism in the development and maintenance of cybersex addiction.
29. Trading Later Rewards for Current Pleasure: Pornography Consumption and Delay Discounting (2015) – Study 1: Participants completed a pornography use questionnaire and a delay discounting task at Time 1 and then again four weeks later. Participants reporting higher initial pornography use demonstrated a higher delay discounting rate at Time 2, controlling for initial delay discounting. Study 2:  Participants who abstained from pornography use demonstrated lower delay discounting than participants who abstained from their favorite food. 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.
30. Sexual Excitability and Dysfunctional Coping Determine Cybersex Addiction in Homosexual Males (2015) – Recent findings have demonstrated an association between CyberSex Addiction (CA) severity and indicators of sexual excitability, and that coping by sexual behaviors mediated the relationship between sexual excitability and CA symptoms. The aim of this study was to test this mediation in a sample of homosexual males.  Questionnaires assessed symptoms of CA, sensitivity to sexual excitation, pornography use motivation, problematic sexual behavior, psychological symptoms, and sexual behaviors in real life and online. Moreover, participants viewed pornographic videos and indicated their sexual arousal before and after the video presentation. Results showed strong correlations between CA symptoms and indicators of sexual arousal and sexual excitability, coping by sexual behaviors, and psychological symptoms. CA was not associated with offline sexual behaviors and weekly cybersex use time. Coping by sexual behaviors partially mediated the relationship between sexual excitability and CA. The results are comparable with those reported for heterosexual males and females in previous studies and are discussed against the background of theoretical assumptions of CA, which highlight the role of positive and negative reinforcement due to cybersex use.
31. Subjective Craving for Pornography and Associative Learning Predict Tendencies Towards Cybersex Addiction in a Sample of Regular Cybersex Users (2016) – There is no consensus regarding the diagnostic criteria of cybersex addiction. Some approaches postulate similarities to substance dependencies, for which associative learning is a crucial mechanism. In this study, 86 heterosexual males completed a Standard Pavlovian to Instrumental Transfer Task modified with pornographic pictures to investigate associative learning in cybersex addiction. Additionally, subjective craving due to watching pornographic pictures and tendencies towards cybersex addiction were assessed. Results showed an effect of subjective craving on tendencies towards cybersex addiction, moderated by associative learning.  Overall, these findings point towards a crucial role of associative learning for the development of cybersex addiction, while providing further empirical evidence for similarities between substance dependencies and cybersex addiction
32. Exploring the Relationship between Sexual Compulsivity and Attentional Bias to Sex-Related Words in a Cohort of Sexually Active Individuals (2016) – This study replicates the findings of this 2014 Cambridge University study that compared the attentional bias of porn addicts to healthy controls. The new study differs: rather than comparing porn addicts to controls, the new study correlated scores on a sex addiction questionnaire to the results of a task assessing attentional bias (explanation of attentional bias). The study described two key results: 1) Higher sexual compulsivity scores correlated with greater interference (increased distraction) during the attentional bias task. This aligns with substance abuse studies. 2) Among those scoring high on sexual addiction, fewer years of sexual experience were related to greater attentional bias. The authors concluded that this result could indicate that more years of “compulsive sexual activity” lead to greater habituation or a general numbing of the pleasure response (desensitization). An excerpt from the conclusion section: “One possible explanation for these results is that as a sexually compulsive individual engages in more compulsive behaviour, an associated arousal template develops and that over time, more extreme behaviour is required for the same level of arousal to be realised. It is further argued that as an individual engages in more compulsive behaviour, neuropathways become desensitized to more ‘normalised’ sexual stimuli or images and individuals turn to more ‘extreme’ stimuli to realise the arousal desired.”
33. Mood changes after watching pornography on the Internet are linked to symptoms of Internet-pornography-viewing disorder (2016) – Excerpts: The main results of the study are that tendencies towards Internet Pornography Disorder (IPD) were associated negatively with feeling generally good, awake, and calm as well as positively with perceived stress in daily life and the motivation to use Internet pornography in terms of excitation seeking and emotional avoidance.  Furthermore, tendencies towards IPD were negatively related to mood before and after watching Internet pornography as well as an actual increase of good and calm mood. The relationship between tendencies towards IPD and excitement seeking due to Internet-pornography use was moderated by the evaluation of the experienced orgasm’s satisfaction. Generally, the results of the study are in line with the hypothesis that IPD is linked to the motivation to find sexual gratification and to avoid or to cope with aversive emotions as well as with the assumption that mood changes following pornography consumption are linked to IPD (Cooper et al., 1999 and Laier and Brand, 2014).
34. Problematic sexual behavior in young adults: Associations across clinical, behavioral, and neurocognitive variables (2016) – Individuals with Problematic Sexual Behaviors (PSB) exhibited several neuro-cognitive deficits. These findings indicate poorer executive functioning (hypofrontality) which is a key brain feature occuring in drug addicts. A few excerpts: From this characterization, it is be possible to trace the problems evident in PSB and additional clinical features, such as emotional dysregulation, to particular cognitive deficits…. If the cognitive problems identified in this analysis are actually the core feature of PSB, this may have notable clinical implications.
35. Executive Functioning of Sexually Compulsive and Non-Sexually Compulsive Men Before and After Watching an Erotic Video (2017) – Exposure to porn affected executive functioning in men with “compulsive sexual behaviors”, but not healthy controls. Poorer executive functioning when exposed to addiction-related cues is a hallmark of substance disorders (indicating both altered prefrontal circuits and sensitization). Excerpts: This finding indicates better cognitive flexibility after sexual stimulation by controls compared with sexually compulsive participants. These data support the idea that sexually compulsive men do not to take advantage of the possible learning effect from experience, which could result in better behavior modification. This also could be understood as a lack of a learning effect by the sexually compulsive group when they were sexually stimulated, similar to what happens in the cycle of sexual addiction, which starts with an increasing amount of sexual cognition, followed by the activation of sexual scripts and then orgasm, very often involving exposure to risky situations.
36. Exposure to Sexual Stimuli Induces Greater Discounting Leading to Increased Involvement in Cyber Delinquency Among Men (2017) – In two studies exposure to visual sexual stimuli resulted in: 1) greater delayed discounting (inability to delay gratification), 2) greater inclination to engage in cyber-deliquency, 3) greater inclination to purchase counterfeit goods & hack someone’s Facebook account. Taken together this indicates that porn use increases impulsivity and may reduce certain executive functions (self-control, judgment, foreseeing consequences, impulse control). Excerpt: These findings provide insight into a strategy for reducing men’s involvement in cyber delinquency; that is, through less exposure to sexual stimuli and promotion of delayed gratification. The current results suggest that the high availability of sexual stimuli in cyberspace may be more closely associated with men’s cyber-delinquent behavior than previously thought.
37. Predictors for (Problematic) Use of Internet Sexually Explicit Material: Role of Trait Sexual Motivation and Implicit Approach Tendencies Towards Sexually Explicit Material (2017) – Excerpts: The present study investigated whether trait sexual motivation and implicit approach tendencies towards sexual material are predictors of problematic SEM use and of the daily time spent watching SEM. In a behavioral experiment, we used the Approach-Avoidance Task (AAT) for measuring implicit approach tendencies towards sexual material. A positive correlation between implicit approach tendency towards SEM and the daily time spent on watching SEM might be explained by attentional effects: A high implicit approach tendency can be interpreted as an attentional bias towards SEM. A subject with this attentional bias might be more attracted to sexual cues on the Internet resulting in higher amounts of time spent on SEM sites.
38. Pornography Addiction Detection based on Neurophysiological Computational Approach (2018) – Excerpt: In this paper, a method of using brain signal from frontal area captured using EEG is proposed to detect whether the participant may have porn addiction or otherwise. It acts as a complementary approach to common psychological questionnaire. Experimental results show that the addicted participants had low alpha waves activity in the frontal brain region compared to non-addicted participants. It can be observed using power spectra computed using Low Resolution Electromagnetic Tomography (LORETA). The theta band also show there is disparity between addicted and non-addicted.
39. Gray matter deficits and altered resting-state connectivity in the superior temporal gyrus among individuals with problematic hypersexual behavior (2018) – fMRI study. Summary: …study showed gray matter deficits and altered functional connectivity in the temporal gyrus among individuals with PHB (sex addicts). More importantly, the diminished structure and functional connectivity were negatively correlated with the severity of PHB. These findings provide new insights into the underlying neural mechanisms of PHB.
40. Tendencies toward Internet-pornography-use disorder: Differences in men and women regarding attentional biases to pornographic stimuli (2018) – Excerpts:  The results of this study showed a relationship between attentional bias and symptom severity of IPD partially mediated by indicators for cue-reactivity and craving. The results support theoretical assumptions of the I-PACE model regarding the incentive salience of addiction-related cues and are consistent with studies addressing cue-reactivity and craving in substance-use disorders.
41. Altered Prefrontal and Inferior Parietal Activity During a Stroop Task in Individuals With Problematic Hypersexual Behavior (2018) -fMRI & neuropsychological study comparing controls to porn/sex addicts. Findings mirror studies on drug addicts: sex/porn addicts exhibited poorer executive control & decreased PFC activation during a stroop test correlating with severity of addiction scores. All this indicates poorer prefrontal cortex functioning, which is a hallmark of addiction, and manifests as the inability to control use or suppress cravings.
42. Trait and state impulsivity in males with tendency towards Internet-pornography-use disorder (Antons & Brand, 2018) – Excerpts: In accordance with dual-process models of addiction, the results may be indicative of an imbalance between the impulsive and reflective systems which might be triggered by pornographic material. This may result in loss of control over the Internet-pornography use albeit experiencing negative consequences.
43. Facets of impulsivity and related aspects differentiate among recreational and unregulated use of Internet pornography (2019) -Excerpts: Individuals with unregulated use showed the highest scores for craving, attentional impulsivity, delay discounting, and dysfunctional coping, and lowest scores for functional coping and need for cognition. The results indicate that some facets of impulsivity and related factors such as craving and a more negative attitude are specific for unregulated IP users. The results are also consistent with models on specific Internet use disorders and addictive behaviors
44. Approach bias for erotic stimuli in heterosexual male college students who use pornography (2019) – Excerpts: Taken together, the results suggest parallels between substance and behavioral addictions (Grant et al., 2010). Pornography use (particularly problematic use) was linked to faster approaches to erotic stimuli than neutral stimuli, an approach bias similar to that observed in alcohol-use disorders (Field et al., 2008; Wiers et al., 2011), cannabis use (Cousijn et al., 2011; Field et al., 2006), and tobacco-use disorders (Bradley et al., 2004).
45. Hypermethylation-associated downregulation of microRNA-4456 in hypersexual disorder with putative influence on oxytocin signalling: A DNA methylation analysis of miRNA genes (Bostrom et al., 2019) – [likely dysfunctional stress system]. Study on subjects with hypersexuality (porn/sex addiction) reports epigenetic changes mirroring those occurring in alcoholics. The epigenetic changes occurred in genes associated with the oxytocin system (which is important in love, bonding, addiction, stress, sexual functioning, etc.).
46. Gray matter volume differences in impulse control and addictive disorders (Draps et al., 2020) –  [hypofrontaility: descreased prefrontal cortex & anterior cingulate cortex  gray matter]. Excerpts: Affected individuals (CSBD, GD, AUD) compared to HC participants showed smaller GMVs in the left frontal pole, specifically in the orbitofrontal cortex. The most pronounced differences were observed in the GD and AUD groups, and the least in the CSBD group. There was a negative correlation between GMVs and disorder severity in the CSBD group. Higher severity of CSBD symptoms was correlated with decreased GMV in the right anterior cingulate gyrus.
47. High Plasma Oxytocin Levels in Men With Hypersexual Disorder (Jokinen et al., 2020) – From the research group that published 4 previous neuro-endocrine studies on male “hypersexuals” (sex/porn addicts). Because oxytocin is involved in our stress response, higher blood levels were interpreted as an indicator of an overactive stress system in the sex addicts. This finding aligns with the researcher’s previous studies and neurological studies reporting a dysfunctional stress response in substance abusers. Interestingly, therapy (CBT) reduced oxytocin levels in hypersexual patients.
48. Inhibitory control and problematic Internet-pornography use – The important balancing role of the insula (Anton & Brand, 2020) – The authors state their results indicate tolerance, a hallmark of an addiction process. Excerpts: Consistent with previous studies (e.g., Antons & Brand, 2018; Brand, Snagowski, Laier, & Maderwald, 2016; Gola et al., 2017; Laier et al., 2013), we found a high correlation between subjective craving and symptom severity of problematic IP use in both conditions. However, the increase in craving as measure for cue-reactivity was not associated with symptom severity of problematic IP use, this may relate to tolerance (cf. Wéry & Billieux, 2017) given that the pornographic images used in this study were not individualized in terms of subjective preferences. Therefore, the standardized pornographic material used may not be strong enough for inducing cue-reactivity in individuals with high symptom severity associated with low effects on the impulsive, reflective, and interoceptive systems as well as inhibitory control ability.
49. Normal Testosterone but Higher Luteinizing Hormone Plasma Levels in Men With Hypersexual Disorder (2020) – From the research group that published 5 previous neuro-endocrine studies on male “hypersexuals” (sex/porn addicts), revealing altered stress systems, a major marker for addiction (1, 2, 3, 4, 5.). Excerpts: The proposed mechanisms might include the HPA and HPG interaction, the reward neural network, or the inhibition of regulation impulse control of prefrontal cortex regions.³² In conclusion, we report for the first time increased LH plasma levels in hypersexual men compared with healthy volunteers. These preliminary findings contribute to growing literature on the involvement of neuroendocrine systems and dysregulation in HD.
50. Approach bias for erotic stimuli among heterosexual female college students who use pornography (2020) – Neuro-psychological study on female porn users reports findings that mirror those seen in substance addiction studies. Approach bias to porn (sensitization) and anhedonia (desensitization) were positively correlated with pornography use. Study also reported: “we also found a significant positive association between erotic approach bias scores and scores on the SHAPS, which quantifies anhedonia. This indicates that the stronger the approach bias for erotic stimuli, the less pleasure the individual reported experiencing“. Put simply, the neuropsychological sign of an addiction process correlated with lack of pleasure (anhedonia).
    
51. Inhibitory control and problematic Internet-pornography use – The important balancing role of the insula (2020) – Excerpts: Effects of tolerance and motivational aspects may explain the better inhibitory control performance in individuals with higher symptom severity which was associated with differential activity of the interoceptive and reflective system. Diminished control over IP use presumably results from the interaction between the impulsive, reflective, and interoceptive systems.
52. Sexual cues alter working memory performance and brain processing in men with compulsive sexual behavior (2020) Excerpts: These findings are in line with the incentive salience theory of addiction, especially the higher functional connectivity to the salience network with the insula as a key hub and the higher lingual activity during processing of pornographic pictures depending on recent pornography consumption.
53. Subjective reward value of visual sexual stimuli is coded in human striatum and orbitofrontal cortex (2020) – Excerpts: We not only found an association of NAcc and caudate activity with sexual arousal ratings during VSS viewing but the strength of this association was greater when the subject reported more problematic pornography use (PPU). The result supports the hypothesis, that incentive value responses in NAcc and caudate differentiate more strongly between differently preferred stimuli, the more a subject experiences PPU. 
54. The Neurosciences of Health Communication: An fNIRS Analysis of Prefrontal Cortex and Porn Consumption in Young Women for the Development of Prevention Health Programs (2020) – Excerpts: The results indicate that the viewing of the pornographic clip (vs. control clip) causes an activation of Brodmann’s area 45 of the right hemisphere. An effect also appears between the level of self-reported consumption and the activation of right BA 45: the higher the level of self-reported consumption, the greater the activation. On the other hand, those participants who have never consumed pornographic material do not show activity of the right BA 45 compared to the control clip (indicating a qualitative difference between non-consumers and consumers. These results are consistent with other research made in the field of addictions.
55. Event-related potentials in a two-choice oddball task of impaired behavioral inhibitory control among males with tendencies towards cybersex addiction (2020) – Excerpts: Theoretically, our results indicate that cybersex addiction resembles substance use disorder and impulse control disorder in terms of impulsivity at electrophysiological and behavioral levels. Our findings may fuel the persistent controversy about the possibility of cybersex addiction as a novel type of psychiatric disorder.
56. Decision-Making in Gambling Disorder, Problematic Pornography Use, and Binge-Eating Disorder: Similarities and Differences (2021) – Excerpts: Similarities between CSBD and addictions have been described, and impaired control, persistent use despite adverse consequences, and tendencies to engage in risky decisions may be shared features (37••, 40). Individuals with these disorders often show impaired cognitive control and disadvantageous decision-making [12, 15,16,17]. Deficits in decision-making processes and goal-directed learning have been found across multiple disorders.

Together these neurological studies reported:

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. And 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 use/exposure to porn related to greater delayed discounting (inability to delay gratification). This is a sign of poorer executive functioning.
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).
9. Greater wanting & craving for porn, but not greater liking. This aligns with the accepted model of addiction – incentive sensitization.
10. Porn addicts have greater preference for sexual novelty yet their brains habituated faster to sexual images. Not pre-existing.
11. The younger the porn users the greater the cue-induced reactivity in the reward center.
12. Higher EEG (P300) readings when porn users were exposed to porn cues (which occurs in other addictions).
13. Less desire for sex with a person correlating with greater cue-reactivity to porn images.
14. More porn use correlated with lower LPP amplitude when briefly viewing sexual photos: indicates habituation or desensitization.
15. Dysfunctional HPA axis and altered brain stress circuits, which occurs in drug addictions (and greater amygdala volume, which is associated with chronic social stress).
16. Epigenetic changes on genes central to the human stress response and closely associated with addiction.
17. Higher levels of Tumor Necrosis Factor (TNF) – which also occurs in drug abuse and addiction.
18. A deficit in temporal cortex gray matter; poorer connectivity between temporal corporate and several other regions.
19. Greater state impulsivity.
20. Decreased prefrontal cortex and anterior cingulate gyrus gray matter compared to healthy controls.

What about neurological studies that debunk porn addiction? There are none. While the lead author of Prause et al., 2015 claimed her lone EEG study falsified pornography addiction, 9 peer-reviewed papers disagree:  The neuroscientists on these 8 papers state that Prause et al. actually found desensitization/habituation (consistent with the development of addiction) as less brain activation to vanilla porn (pictures) was related to greater porn use. Unbelievably, the Prause et al. team boldly claimed to have falsified the porn addiction model with a single paragraph taken from this 2016 “letter to the editor.” In reality the Prause letter falsified nothing, as this extensive critique reveals: Letter to the editor “Prause et al. (2015) the latest falsification of addiction predictions” (2016).

While we wait for further brain studies on porn users, over 340+ brain studies have already confirmed that “Internet addicts” develop the same major brain changes that occur in all addictions  However, these studies did not separate out porn addiction from other types of Internet addictions. Who uses the Internet for only porn? In fact, researchers have already looked into the brains of over-eaters, Internet users and video-gamers (and drug addicts). In each case, researchers have discovered that non-drug stimuli at sufficient intensity cause three major brain changes caused by addiction – desensitization, sensitization, and hypofrontality. (Also see: Internet Addiction Summaries, Recent Internet Addiction Brain Studies Include Porn, and Internet Addiction Studies Containing Excerpts About Porn).

Why are there not even more studies on porn users? Sexual politics once obscured the increased vulnerability of those pursuing cybersex/porn. 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 a natural reward that we’re all wired to pursue: apparent mating opportunities.

Meanwhile, the “not sufficient scientific evidence” argument is not a sound argument where there has not been much in-depth study. Keep in mind that the tobacco companies long used the “little scientific evidence” argument to defend against the overwhelming circumstantial evidence that cigarettes were lethal. In fact, they hired doctors to do commercials assuring smokers that “Smoking is good for your lungs.”

Science marches faster with less controversial behavioral addictions. Every month, new studies appear showing addictive processes in the brains of others who have used supernormal versions of natural rewards to excess (gamblers, over-eaters, video gamers etc.). This is why, in 2011, the 3000 doctors of the American Society for Addiction Medicine (ASAM) came out with a public statement clarifying that behavioral addictions (sex, food, gambling) are fundamentally like substance addictions in terms of brain changes.

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.— The American Society of Addiction Medicine (ASAM)

But ‘porn addiction’ isn’t in the APA’s DSM-5, right? When the APA last updated the manual in 2013 (DSM-5), it didn’t formally consider “internet porn addiction,” opting instead to debate “hypersexual disorder.” The latter umbrella term for problematic sexual behavior was recommended for inclusion by the DSM-5’s own Sexuality Work Group after years of review. However, in an eleventh-hour “star chamber” session (according to a Work Group member), other DSM-5 officials unilaterally rejected hypersexuality, citing reasons that have been described as illogical.

Just prior to the DSM-5’s publication in 2013, Thomas Insel, then Director of the National Institute of Mental Health, warned that it was time for the mental health field to stop relying on the DSM. Its “weakness is its lack of validity,” he explained, and “we cannot succeed if we use DSM categories as the “gold standard.” He added, “That is why NIMH will be re-orienting its research away from DSM categories.” In other words, the NIMH planned to stop funding research based on DSM labels (and their absence).

The World Health Organization appears poised to set right the APA’s excessive caution. The next edition of its diagnostic manual, the ICD, is due out in 2018. The beta draft of the new ICD-11 includes a diagnosis for “Compulsive sexual behavior disorder,” as well as one for “Disorders due to addictive behaviors.”

Moreover, there’s a growing body of research linking porn use or porn/sex addiction to sexual dysfunctions, lower brain activation to sexual stimuli, and lower sexual satisfaction. And plenty of anecdotal evidence of problematic porn use. Self-reports of distressed users—more and more of them in their twenties or even younger—recount:

• Distress about escalation to more extreme porn
• Delayed ejaculation
• Copulatory impotence (can get it up for porn, but not partners)
• Frequent masturbation, little satisfaction
• Uncharacteristic, worsening social anxiety or lack of confidence
• Growing erectile dysfunction, even with extreme porn.
• Morphing porn tastes that don’t match sexual orientation (such as HOCD)
• Inability to concentrate, extreme restlessness
• Depression, anxiety, brain fog

There is sometimes an outdated assumption among non-addiction experts that these users are a tiny minority with preexisting conditions that make them uniquely vulnerable to addiction (‘impulsives’ or ‘novelty-seekers,’ perhaps). Yet new research is not bearing that assumption out. Moreover, when porn users stop overstimulating their brains, many bounce back to excellent emotional health. This suggests that “normal” brains are vulnerable to today’s hypersexual stimulation.

The fact that not everyone who uses porn uses it to a point where it interferes with his life doesn’t prove it cannot cause addiction. Not everyone who uses alcohol becomes an alcoholic, yet alcohol is unquestionably potentially addictive. Some experts meanwhile hesitate to label compulsive Internet porn use as an addiction because past research hasn’t sufficiently revealed the withdrawal and tolerance phenomena. However, it’s considered likely that the “missing” research is due to methodological challenges rather than the absence of the phenomena themselves. In the absence of formal research, here are numerous self-reports of withdrawal symptoms and evidence of tolerance culled from anonymous online posts of recovering users:

• Withdrawal
• Tolerance

As of 2019, over 55 studies reporting findings consistent with escalation of porn use (tolerance), habituation to porn, and even withdrawal symptoms (all signs and symptoms associated with addiction).

The upper limit of natural dopamine release is sex. In theory, porn cannot be higher than sex. Obviously, most people have sex without becoming addicted to it. This is very confusing, and one reason why most psychologists once denied that porn addiction existed. However, it’s likely that

1. chronic use (many hits on demand, like smoking packs of cigarettes, which is very addictive—more so than heroin use, in fact, because the latter happens with less frequency even though the buzz is bigger), and
2. overriding natural satiation mechanisms

both contribute to dopamine dysregulation and addiction. Moreover, as youngsters start out on streaming porn, their brains appear to be wiring sexual arousal to the unique attributes of screens: voyeurism, endless novelty, ease of escalation to more extreme stimulation, particular fetishes, etc. Even if they don’t become addicts, many users are reporting sexual difficulties with real partners: Studies linking porn use or porn/sex addiction to sexual dysfunctions, lower brain activation to sexual stimuli, and lower sexual satisfaction.

With respect to the first point, there are likely to be more Internet porn addicts in the making than sex addicts, because a porn user can obtain constant hits of dopamine merely by clicking for free, whereas a sex addict must go through an entire seduction or other ritual. With respect to the second point about overriding normal satiety, consider obese people for a moment. Brain research shows that most are addicted to food, i.e., that their dopamine receptors have declined. Yet eating fattening or sweet food releases only half as much dopamine as sex/masturbation. Overriding feelings of fullness/satiety (eating when you’re not really hungry, masturbating when you’re not really horny) appears to cause dopamine dysregulation in some.

There’s also something called ‘sensitization‘ at work in addicts’ brains, and multiple studies listed at the top of this page have found evidence of sensitization in porn users.

Time for informed choices

Now that so many Internet users have unrestricted access to today’s porn they need to be able to make informed choices about its effects. Informed choice calls for in-depth research about the longer-term effects of the frequent use of hypersexual materials. Meanwhile, it is wise to make personal experiments by removing internet porn from your life for a few months and draw your own conclusions.

It would be good if researchers asked porn users to remove porn to isolate its effects. More research also needs to ask:

• How many users are showing symptoms, in which age groups?
• What percentage of the general population, without pre-existing disorders, become addicted or develop porn-related pathologies?
• How many compulsive Internet porn users had no other addiction prior to use?
• How long does it typically take heavy users to progress from asymptomatic to symptomatic? (In this regard, most of the users who have offered recovery self-reports firmly believed Internet porn was harmless for years before their symptoms gradually became too severe to ignore.)
• Are porn users inadvertently rewiring their sexual tastes as they use?
• Are youthful erectile dysfunction and numbed clitorises from vibrator use (which women report) related to porn-use related brain changes?
• Is there a trend toward compulsive use, such that the percentage of porn addicts rises as stimuli grow more extreme? (Particularly important now that virtual reality porn has arrived.)
• To what extent are pubescent/adolescent brains more vulnerable to porn addiction than adult brains?
• How long does it generally take the brains of those adversely affected to bounce back to normal sensitivity when they quit, and what turning points reflect which neurochemical events?

Fifty years ago, as our diet was flooded with junk-food, our culture assumed that self-control would protect people against obesity—except for an unlucky few who were predisposed to become fat due to genetic vulnerability. Today, 79% of Americans have a BMI of 25+ (18.5-24.9 is normal, 30 obese), and about half of those are already at 30+. And the USA is only the eighth fattest country. As our diets have changed, so have our appetites. Our ability to register satiety has declined. Can we assume self-control is adequate protection against this phenomenon in the case of supernormally stimulating, streaming porn consumption?

Just as our ancestors didn’t have access to plentiful, cheap food calculated to titillate human taste buds, they also didn’t have access to novel sexual titillation at a swipe or click. Numbed brains seek more stimulation, so the ubiquitous options to goose the brain by swiping/clicking to porn or gulping a soda constitute a risk that past generations didn’t face. It’s likely that “unnatural” versions of natural reinforcers may put at risk more of the user population than do other addictive substances/behaviors.

A rapidly changing reality, such as the recent lightening-like transition from porn magazines to streaming online pornography, can leave research behind the curve. Perhaps the necessary brain research on porn users and recovered porn users could help both sides of the noisy porn debate to see which fears are well grounded and which make the effects of porn more dangerous by making its use risky or forbidden.