Debunking the debunker: Critique of letter to the editor “Prause et al. (2015) the latest falsification of addiction predictions”

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Introduction: In various comments, articles and tweets Nicole Prause has claimed that not only did Prause et al., 2015 falsify "a core tenet of the addiction model, the cue reactivity biomarker," but that "a series of behavioral studies replicated by independent laboratories [falsify] other predictions of the addiction model." Prause cites the Letter to the Editor (critiqued here) as her supporting evidence. Put simply, Prause has gathered all her debunking eggs into one basket - the single paragraph excerpted below. This YBOP response serves as a debunking of the debunker (Nicole Prause) and all her favorite "eggs."

In response to neuroscientist Matuesz Gola's critical analysis of their 2015 EEG study (Prause et al., 2015), Prause et al. wrote their own Letter to the Editor, entitled, "Prause et al. (2015) the latest falsification of addiction predictions," which we will refer to as the "Reply to Gola." (Interestingly, the editor's original "accepted manuscript" of the Reply to Gola listed only Nicole Prause as the author, so it's unclear if her co-authors participated in crafting the Reply to Gola, or whether it was a solo effort by Prause.)

Certainly, most of the Reply to Gola is devoted to attempts to defend the Prause et al., 2015 interpretations. Back in 2015 Nicole Prause made over-the-top claims that her team's anomalous study had singlehandedly "debunked porn addiction." What legitimate researcher would ever claim to have "debunked" an entire field of research and to have "falsified" all previous studies with a single EEG study?

Now, in 2016, the Reply to Gola's closing paragraph puts forward an equally unwarranted assertion that a handful of papers, spearheaded by Prause's single EEG study, falsify "multiple predictions of the addiction model."

In Section #1 below we debunk the falsification claim by revealing what the papers cited in the Reply to Gola actually found (and did not find), as well as bringing to light the many relevant studies omitted. In Section #2 below, we examine other unsupported claims and inaccuracies in the Reply to Gola. Before we begin, here are links to the pertinent items:

  1. Modulation of Late Positive Potentials by Sexual Images in Problem Users and Controls Inconsistent with "Porn Addiction" (Prause et al., 2015) Nicole Prause, Vaughn R. Steele, Cameron Staley, Dean Sabatinelli, Greg Hajcake.
  2. The YBOP critique of Prause et al., 2015.
  3. Six peer-reviewed analyses of Prause et al., 2015: 1, 2, 3, 4, 56. (All agree that Prause actually found desensitization or habituation - consistent with addiction)
  4. Matuesz Gola's critique of Prause et al., 2015: Decreased LPP for sexual images in problematic pornography users may be consistent with addiction models. Everything depends on the model. (Commentary on Prause, Steele, Staley, Sabatinelli, & Hajcak, 2015).
  5. The Reply to Gola itself: Prause et al. (2015) the latest falsification of addiction predictions.

SECTION ONE: Debunking the Prause et al. Claimed Falsification of The Addiction Model

This is the closing paragraph where Prause et al. summarizes the evidence purporting to falsify the porn addiction model:

"In closing, we highlight the Popperian falsification of multiple predictions of the addiction model using multiple methods. Most addiction models require that addicted individuals exhibit less control over their urge to use (or engage in the behavior); those reporting more problems with viewing sexual images actually have better control over their sexual response (replicated by Moholy, Prause, Proudfit, Rahman, & Fong, 2015; first study by Winters, Christoff, & Gorzalka, 2009). Addiction models typically predict negative consequences. Although erectile dysfunction is the most commonly suggested negative consequence of porn use, erectile problems actually are not elevated by viewing more sex films (Landripet & Štulhofer, 2015; Prause & Pfaus, 2015; Sutton, Stratton, Pytyck, Kolla, & Cantor, 2015). Addiction models often propose that the substance use or behavior is used to ameliorate or escape negative affect. Those reporting problems with sex films actually reported less negative affect at baseline/pre-viewing than controls (Prause, Staley, & Fong, 2013). Meanwhile, two more compelling models have received more support since the publication of Prause et al. (2015). These include a high sex drive model (Walton, Lykins, & Bhullar, 2016) supporting the original high-drive hypothesis (Steele, Prause, Staley, & Fong, 2013). Parsons et al. (2015) have suggested that high sex drive may represent a subset of those reporting problems. Also, distress related to viewing sex films has been shown to be most strongly related to conservative values and religious history (Grubbs et al., 2014). This supports a social shame model of problem sex film viewing behaviors. The discussion should move from testing the addiction model of sex film viewing, which has had multiple predictions falsified by independent laboratory replications, to identifying a better fitting model of those behaviors."

Before we address each of the above assertions, it's important to reveal what Prause et al. chose to omit from the so-called "falsification":

  1. Studies on actual porn addicts. You read that right. Of all the studies cited, only one contained a group of porn addicts, and 71% of those subjects reported severe negative effects. Bottom line: You cannot falsify "porn addiction" if the studies you cite don't investigate porn addicts.
  2. All the neurological studies published on porn users and sex addicts - because all support the addiction model. This page lists 37 neuroscience-based studies (MRI, fMRI, EEG, Neurospychological, Hormonal) providing strong support for the addiction model.
  3. All the peer-reviewed reviews of the literature - because all support the porn addiction model. Here are 12 literature reviews by some of the top neuroscientists in the world, supporting the porn addiction model.
  4. 22 studies linking porn use/sex addiction to sexual problems & lower arousal. The first 3 studies in the list demonstrate causation, as participants eliminated porn use and healed chronic sexual dysfunctions.
  5. Over 50 studies linking porn use to less sexual and relationship satisfaction.
  6. Over 15 studies reporting findings consistent with escalation of porn use (tolerance), habituation to porn, and even withdrawal symptoms. 
  7. Over 40 studies linking porn use to poorer mental-emotional health & poorer cognitive outcomes.
  8. Over 25 studies linking porn use to "un-egalitarian attitudes" toward women
  9. All the many studies on adolescents, which report porn use is related to poorer academics, more sexist attitudes, more aggression, poorer health, poorer relationships, lower life satisfaction, viewing people as objects, increased sexual risk taking, less condom use, greater sexual violence, greater sexual coercion, less sexual satisfaction, lower libido, greater permissive attitudes, and a whole lot more. (In short, ED is not the "most commonly suggested negative consequence of porn use" as claimed in the Reply to Gola below.)

In the Reply to Gola, Prause et al. attempt to falsify each of the following Claims ("predictions") relating to the addiction model. The relevant excerpts and supporting studies from the Reply to Gola are given in full, followed by comments.


Claim 1: The inability to control use despite negative consequences.

PRAUSE: "Most addiction models require that addicted individuals exhibit less control over their urge to use (or engage in the behavior); those reporting more problems with viewing sexual images actually have better control over their sexual response (replicated by Moholy, Prause, Proudfit, Rahman, & Fong, 2015; first study by Winters, Christoff, & Gorzalka, 2009)"

The 2 studies cited falsified nothing as they did not assess if subjects had trouble controlling their porn use. Most importantly, neither study started by assessing who was or wasn't a "porn addict." How can you debunk the porn addiction model if you don't begin by assessing subjects with clear evidence of (what addiction experts define as) addiction? Let's briefly examine what the 2 studies actually assessed and reported, and why they falsify nothing:

Winters, Christoff, & Gorzalka, 2009 (Dysregulated Sexuality and High Sexual Desire: Distinct Constructs?):

  • The purpose of this study was to see if men could dampen their self-reported sexual arousal while watching sex films. The important findings: the men best at suppressing sexual arousal were also best at making themselves laugh. The men least successful at suppressing sexual arousal were generally hornier than the rest. These findings have nothing to do with actual porn addicts' "inability to control use despite severe negative consequences."
  • This online anonymous survey did not assess who was and who wasn't a "porn addict," because the assessment tool was the "Sexual Compulsivity Scale" (SCS). The SCS isn't a valid assessment test for Internet-porn addiction or for women, so the study's findings do not apply to internet porn addicts. The SCS was created in 1995 and designed with uncontrolled sexual relations in mind (in connection with investigating the AIDS epidemic). The SCS says:

"The scale has been shown to predict rates of sexual behaviors, numbers of sexual partners, practice of a variety of sexual behaviors, and histories of sexually transmitted diseases."

Moholy, Prause, Proudfit, Rahman, & Fong, 2015 (Sexual desire, not hypersexuality, predicts self-regulation of sexual arousal):

  • This study, like the above study, did not assess which participants were or were not "porn addicts." This study relied upon the CBSOB, which has zero questions about Internet porn use. It only asks about "sexual activities," or if subjects are worried about their activities (e.g., "I am worried I am pregnant," "I gave someone HIV," "I experienced financial problems"). Thus any correlations between scores on the CBSOB and ability to regulate arousal are not relevant to many internet porn addicts, who do not engage in partnered sex.
  • Like the Winters study above, this study reported that hornier participants had a harder time down-regulating their sexual arousal while watching porn. Prause et al. are right: this study replicated Winters, et al., 2009: hornier people have higher sexual desire. (Duh)
  • This study has the same fatal flaw seen in other Prause-team studies: The researchers chose vastly different subjects (women, men, heterosexuals, non-heterosexuals), but showed them all standard, possibly uninteresting, male+female porn. Put simply, the results of this study were dependent on the premise that males, females, and non-heterosexuals do not differ in their response to a set of sexual images. This is clearly not the case.

Even though neither study identified which participants were porn addicts, the Reply to Gola seems to claim that actual "porn addicts" should be the least able to control their sexual arousal while viewing porn. Yet why would the Reply to Gola's authors think porn addicts should have "higher arousal' when Prause et al., 2015 reported that "porn addicts" had less brain activation to vanilla porn than did controls? (Incidentally, another EEG study also found that greater porn use in women correlated with less brain activation to porn.) The findings of Prause et al. 2015 align 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. 2015's EEG findings also align with Banca et al. 2015, which found faster habituation to sexual images in porn addicts. Lower EEG readings mean that subjects are paying less attention to the pictures. The more frequent porn users were probably bored by vanilla porn shown in the lab. Moholy & Prause's compulsive porn users did not "have better control over their sexual response." Instead, they had become habituated or desensitized to static images of vanilla porn.

It is not uncommon for frequent porn users to develop tolerance, which is the need for greater stimulation in order to achieve the same level of arousal. A similar phenomenon occurs in substance abusers who require bigger "hits" to achieve the same high. With porn users, greater stimulation is often achieved by escalating to new or extreme genres of porn.

New genres that induce shock, surprise, violation of expectations or even anxiety can function to increase sexual arousal, which often flags in those who overuse internet porn. A recent study found that such escalation is very common in today's internet porn users. 49% of the men surveyed had viewed porn that "was not previously interesting to them or that they considered disgusting." In sum, multiple studies have reported habituation or escalation in frequent porn users - an effect entirely consistent with the addiction model. 

Key point: This entire claim in the Reply to Gola rests upon the unsupported prediction that "porn addicts" should experience greater sexual arousal to static images of vanilla porn, and thus less ability to control their arousal. Yet the prediction that compulsive porn users or addicts experience greater arousal to vanilla porn and greater sexual desire has repeatedly been falsified by several lines of research:

  1. 22 studies link porn use to lower sexual arousal or sexual dysfunctions with sex partners.
  2. 22 studies falsify the claim that sex and porn addicts "have high sexual desire" (more below).
  3. Over 50 studies link porn use with lower sexual & relationship satisfaction.

In summary:

  • The two studies cited have nothing to do with porn addicts' inability to control use despite negative consequences.
  • The two studies cited did not identify who was or wasn't a porn addict, so can tell us nothing about "porn addiction."
  • Those subjects who scored higher on the sex addiction questionnaire (not porn addiction) did not "control their arousal better" while viewing vanilla porn. They were very likely bored by the vanilla porn (i.e., desensitized, which is an addiction-related brain change).

Claim 2: Addicts use the substance or behavior to escape negative emotions

PRAUSE: "Addiction models often propose that the substance use or behavior is used to ameliorate or escape negative affect. Those reporting problems with sex films actually reported less negative affect at baseline/pre-viewing than controls (Prause, Staley, & Fong, 2013)."

While addicts often do use to escape negative affect (emotions), once again the Reply to Gola cites as support a study that has nothing to do with falsifying the above addiction prediction. Prause, Staley & Fong 2013 did not examine this phenomenon at all. Here's what it actually reported:

"Unexpectedly, the VSS-P group exhibited significantly less coactivation of positive and negative affect to the sexual film than VSS-C."

Translation: the so-called "porn addicts" (VSS-P group) had less emotional reaction to porn than did the control group (VSS-C). Put simply, "porn addicts" experienced less emotional response to both sexual and neutral films. Key point: Prause's 2013 study used the same subjects as Prause et al., 2015, which is the very same 2015 EEG study that found less brain activation to static images of vanilla porn.

There's a very simple explanation for the "more frequent porn users" having less emotional response to viewing vanilla porn. Vanilla porn no longer registered as all that interesting. The same goes "more frequent porn users" reactions to the neutral films - they were desensitized. Prause, Staley, & Fong, 2013 (also called Prause et al., 2013) has been thoroughly critiqued here.

A few patterns emerge in the Reply to Gola's claims of falsification:

  1. The studies cited have nothing to do with the falsification of the porn addiction model.
  2. Prause often cites her own studies.
  3. The 3 Prause Studies (Prause et al., 2013, Prause et al., 2015, Steele et al., 2013.) all involved the same subjects.

Here's what we know about the "porn addicted users" in Prause's 3 studies (the "Prause Studies"): They were not necessarily addicts, as they were never assessed for porn addiction. Thus, they can't legitimately be used to "falsify" anything to do with the addiction model. As a group they were desensitized or habituated to vanilla porn, which is consistent with predictions of the addiction model. Here's what each study actually reported about the "porn addicted" subjects:

  1. Prause et al., 2013: "Porn addicted users" reported more boredom and distraction while viewing vanilla porn.
  2. Steele et al., 2013: Individuals with greater cue-reactivity to porn had less desire for sex with a partner, but not less desire to masturbate.
  3. Prause et al., 2015: "Porn addicted users" had less brain activation to static images of vanilla porn. Lower EEG readings mean that the "porn addicted" subjects were paying less attention to the pictures. 

A clear pattern emerges from the three studies: The "porn addicted users" were desensitized or habituated to vanilla porn, and those with greater cue-reactivity to porn preferred to masturbate to porn than have sex with a real person. Put simply they were desensitized (a common indication of addiction) and preferred artificial stimuli to a very powerful natural reward (partnered sex). There is no way to interpret these results as falsifying porn addiction.

You cannot falsify the porn addiction model if your "porn addicts" are not really porn addicts.

A major flaw in the Prause Studies is that no one knows which, if any, of Prause's subjects were actually porn addicts. This is why there are often quotation marks around "porn addicts" in our descriptions of these 3 studies. The subjects were recruited from Pocatello, Idaho via online advertisements requesting people who were "experiencing problems regulating their viewing of sexual images.” Pocatello, Idaho is over 50% Mormon, so many of the subjects may feel that any amount of porn use is a serious problem.

In a 2013 interview Nicole Prause admits that a number of her subjects experienced only minor problems (which means they were not porn addicts):

"This study only included people who reported problems, ranging from relatively minor to overwhelming problems, controlling their viewing of visual sexual stimuli."

Again, the questionnaire employed in the 3 studies to assess "porn addiction" (Sexual Compulsivity Scale) was not validated as a screening instrument for porn addiction. It was created in 1995 and designed with uncontrolled sexual relations (with partners) in mind, in connection with investigating the AIDS epidemic. The SCS says:

"The scale has been should [shown?] to predict rates of sexual behaviors, numbers of sexual partners, practice of a variety of sexual behaviors, and histories of sexually transmitted diseases."

Moreover, the Prause Studies administered the questionnaire to the female subjects. Yet the SCS's developer warns that this tool won't show psychopathology in women,

"Associations between sexual compulsivity scores and other markers of psychopathology showed different patterns for men and women; sexual compulsivity was associated with indexes of psychopathology in men but not in women."

Besides not establishing which of the subjects were porn addicted, the Prause Studies did not screen subjects for mental disorders, compulsive behaviors, or other addictions. This is critically important for any "brain study" on addiction, lest confounds render results meaningless. Another fatal flaw is that the Prause study subjects were not heterogeneous. They were men and women, including 7 non-heterosexuals, but were all shown standard, possibly uninteresting, male+female porn. This alone discounts any findings. Why? Study after study confirms that men and women have significantly different brain responses to sexual images or films. This is why serious addiction researchers match subjects carefully.

In summary,

  • The study cited in the Reply to Gola (Prause et al., 2013) has nothing to do with assessing a porn addicts' motivations for using porn. It certainly does not assess the extent to which porn addicts use porn to escape negative feelings.
  • The Prause Studies did not assess whether the subjects were porn addicts or not. The authors admitted that many of the subjects had little difficulty controlling use. All of the subjects would have to have been confirmed porn addicts to permit a legitimate comparison with a group of non-porn addicts.
  • All valid brain studies must have homogeneous subjects for accurate comparisons. Since the Prause Studies did not, the results are unreliable, and cannot be used to falsify anything.

Claim: Porn addicts simply have a "high sex drive"

PRAUSE: Meanwhile, two more compelling models have received more support since the publication of Prause et al. (2015). These include a high sex drive model (Walton, Lykins, & Bhullar, 2016) supporting the original high-drive hypothesis (Steele, Prause, Staley, & Fong, 2013). Parsons et al. (2015) have suggested that high sex drive may represent a subset of those reporting problems.

The claim that porn and sex addicts simply have "high sexual desire," has been falsified by 22 recent studies. In fact, Nicole Prause stated in this Quora post that she no longer believes that "sex addicts" have high libidos:

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

No matter what any study has reported it's important to address the spurious claim that "high sexual desire" is mutually exclusive with porn addiction. Its irrationality becomes clear if one considers hypotheticals based on other addictions. (For more, see this critique of Steele, Prause, Staley, & Fong, 2013 High desire’, or ‘merely’ an addiction? A response to Steele et al., 2013). For example, does such logic mean that being morbidly obese, unable to control eating, and being extremely unhappy about it, is simply a "high desire for food?"

Extrapolating further, one must conclude that alcoholics simply have a high desire for alcohol, right? The fact is that all addicts have "high desire" for their addictive substances and activities (called "sensitization"), even when their enjoyment of such activities declines due to other addiction-related brain changes (desensitization). However, it doesn't annul their addiction (which remains a pathology).

Most addiction experts consider "continued use despite negative consequences" to be the prime marker of addiction. After all, someone could have porn-induced erectile dysfunction and be unable to venture beyond his computer in his mother's basement due to porn's effects on his motivation and social skills. Yet, according to these researchers, as long as he indicates "high sexual desire," he has no addiction. This paradigm ignores everything known about addiction, including symptoms and behaviors shared by all addicts, such as severe negative repercussions, inability to control use, cravings, etc.

Let's look more closely at the 3 studies cited in support of the above "high desire" claim:

1. Steele, Prause, Staley, & Fong, 2013 (Sexual desire, not hypersexuality, is related to neurophysiological responses elicited by sexual images):

We discussed this study above (Steele et al., 2013). In 2013 spokesperson Nicole Prause made two unsupported public claims about Steele et al., 2013:

  1. That subjects' brain response differed from those seen in other types of addicts (cocaine was the example)
  2. That frequent porn users merely had "high sexual desire."

Claim #1) The study reported higher EEG readings 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. This finding supports the porn addiction model, as 5 peer-reviewed papers analyizing Steele et al. explained (1, 2, 3, 4, 5.) and psychology professor emeritus John A. Johnson pointed out in a comment under a 2013 Psychology Today Prause interview:

"My mind still boggles at the Prause claim that her subjects' brains did not respond to sexual images like drug addicts' brains respond to their drug, given that she reports higher P300 readings for the sexual images. Just like addicts who show P300 spikes when presented with their drug of choice. How could she draw a conclusion that is the opposite of the actual results?"

Dr. Johnson, who has no opinion on sex addiction, commented critically a second time under the Prause interview:

Mustanski asks, "What was the purpose of the study?" And Prause replies, "Our study tested whether people who report such problems [problems with regulating their viewing of online erotica] look like other addicts from their brain responses to sexual images."

But the study did not compare brain recordings from persons having problems regulating their viewing of online erotica to brain recordings from drug addicts and brain recordings from a non-addict control group, which would have been the obvious way to see if brain responses from the troubled group look more like the brain responses of addicts or non-addicts.....

Claim #2) Study spokesperson Nicole Prause claimed that porn users merely had "high sexual desire," yet the study reported greater cue-reactivity to porn correlating with less desire for partnered sex. To put another way, individuals with greater brain activation to porn would rather masturbate to porn than have sex with a real person. That's not "high sexual desire." An excerpt from a critique of Steele et al. taken from this 2015 review of the literature:

Moreover, the conclusion listed in the abstract, “Implications for understanding hypersexuality as high desire, rather than disordered, are discussed” [303] (p. 1) seems out of place considering the study’s finding that P300 amplitude was negatively correlated with desire for sex with a partner. As explained in Hilton (2014), this finding “directly contradicts the interpretation of P300 as high desire” [307]. The Hilton analysis further suggests that the absence of a control group and the inability of EEG technology to discriminate between “high sexual desire” and “sexual compulsion” render the Steele et al. findings uninterpretable [307].

Bottom line: The findings of Steele et al., 2013 actually falsify the assertions made in the Reply to Gola.

2. Parsons et al., 2015 (Hypersexual, Sexually Compulsive, or Just Highly Sexually Active? Investigating Three Distinct Groups of Gay and Bisexual Men and Their Profiles of HIV-Related Sexual Risk):

Like nearly every study cited in the Reply to Gola, this study failed to assess which subjects were, in fact, porn addicted. It employed two questionnaires that asked only about sexual behaviors: the "Sexual Compulsivity Scale" (discussed above), and the "Hypersexual Disorder Screening Inventory." Neither questionnaire contained a single item about internet porn use, so this study can tell us nothing about internet porn addiction.

While Parsons et al., 2015 only concerns itself with sexual behaviors in gay and bisexual men, its findings actually falsify the claim that "sex addiction is merely high sexual desire." If high sexual desire and sex addiction were the same, there would only be one group of individuals per population. Instead, this study reported several distinct sub-groups, yet all groups reported similar rates of sexual activity.  

Emerging research supports the notion that sexual compulsivity (SC) and hypersexual disorder (HD) among gay and bisexual men (GBM) might be conceptualized as comprising three groups—Neither sexually compulsive nor hypersexual; Sexually compulsive only, and Both sexually compulsive and hypersexual—that capture distinct levels of severity across the SC/HD continuum. Nearly half (48.9 %) of this highly sexually active sample was classified as Neither SC nor HD, 30 % as SC Only, and 21.1 % as Both SC and HD. While we found no significant differences between the three groups on reported number of male partners, anal sex acts....

Simplified: High sexual desire, as measured by sexual activity, tells us very little about whether a person is a sex addict or not. The key finding here is that sex addiction is not the same as "high sexual desire."

3. Walton, Lykins, & Bhullar, 2016 (Beyond Heterosexual, Bisexual, and Homosexual A Diversity in Sexual Identity Expression):

Why this "letter to the editor" is cited remains a mystery. It's not a peer-reviewed study and it has nothing to do with porn use, porn addiction, or hypersexuality. Are the authors of the Reply to Gola padding their citation count with irrelevant papers?

In summary:

  • The three studies cited did not assess whether any subject was porn addicted or not. As a result, they can tell us little about the claim that porn addicts simply have high sexual desire.
  • Steele, Prause, Staley, & Fong, 2013 reported that greater cue-reactivity to porn was related to less desire for sex with a partner. This falsifies the claim that porn addicts have high sexual desire.
  • Parsons et al., 2015 reported that sexual activity was unrelated to measures of hypersexuality. This falsifies the claim that "sex addicts" simply have high sexual desire.
  • Walton, Lykins, & Bhullar, 2016 is a letter to the editor that has nothing to do with the subject at hand.

Claim: Erectile dysfunction is the most commonly suggested negative consequence of porn use.

PRAUSE: Addiction models typically predict negative consequences. Although erectile dysfunction is the most commonly suggested negative consequence of porn use, erectile problems actually are not elevated by viewing more sex films (Landripet & Štulhofer, 2015; Prause & Pfaus, 2015; Sutton, Stratton, Pytyck, Kolla, & Cantor, 2015).

The claim that "erectile dysfunction is the most common negative consequence of porn use" is without support. It's a straw man argument as:

  1. No peer-reviewed paper has ever claimed that erectile dysfunction is the #1 consequence of porn use.
  2. The #1 consequence of porn use has never been described in a peer-reviewed paper (and probably never will be).
  3. This claim limits itself to the consequences of porn use, which is not the same as the consequences of porn addiction.

How could erectile dysfunction be the #1 negative consequence of porn use when the female half of the population is omitted? If any sexual problem were the number one consequence of porn use it would have to be low libido or anorgasmia, so as to include females.

In any case, only one of the three studies cited actually identified which subjects, if any, were porn addicted: Sutton, Stratton, Pytyck, Kolla, & Cantor, 2015. Indeed, this is the only study cited in the entire Reply to Gola that identifies any study participants as porn addicts. The two other studies cited here (Landripet & Štulhofer, 2015; Prause & Pfaus, 2015) tell us nothing about the relationship between porn addiction and erectile dysfunction because neither assessed whether any subject was porn addicted or not. Sound familiar?

So, let's first examine the only relevant study cited in the Reply to Gola.

Sutton, Stratton, Pytyck, Kolla, & Cantor, 2015 (Patient Characteristics by Type of Hypersexuality Referral: A Quantitative Chart Review of 115 Consecutive Male Cases):

It's a study on men (average age 41.5) seeking treatment for hypersexuality disorders, such as paraphilias and chronic masturbation or adultery. 27 were classified as "avoidant masturbators," meaning they masturbated (typically with porn use) one or more hours per day or more than 7 hours per week. 71% of the compulsive porn users reported sexual functioning problems, with 33% reporting delayed ejaculation (often a precursor to porn-induced ED).

What sexual dysfunction do 38% of the remaining men have? The study doesn't say, and the authors have ignored repeated requests for details. Two primary choices for male sexual dysfunction in this age group are ED and low libido. The men were not asked about their erectile functioning without porn. Often men have no idea that they have porn-induced ED if they aren't having partnered sex and all their climaxes entail masturbation to porn. This means sexual problems might have been higher than 71% in the porn addicts. Why the Reply to Gola cited this study as evidence that "negative consequences" are not associated with porn addiction remains a mystery.

Sutton et al., 2015 has been replicated by the only other study to directly investigate the relationships between sexual dysfunctions and problematic internet porn use. A 2016 Belgian study from a leading research university found problematic internet porn use was associated with reduced erectile function and reduced overall sexual satisfaction. Yet problematic porn users experienced greater cravings. The study also appears to report escalation, as 49% of the men viewed porn that "was not previously interesting to them or that they considered disgusting."

In fact, 22 studies have replicated this link between porn use/porn addiction and sexual dysfunctions or decreased sexual arousal. The first 3 studies in that list demonstrate causation as participants eliminated porn use and healed chronic sexual dysfunctions. In addition, over 50 studies correlate porn use with lower sexual and relationship satisfaction. Sounds like "negative consequences of porn use" to me.

While "debunking" porn-induced sexual dysfunctions has no bearing on the existence of "porn addiction," we turn next to examining the first two studies cited above for the claim there's little relationship between erectile dysfunction and current levels of porn use.

First, it's important to know that studies assessing young male sexuality since 2010 report historic levels of sexual dysfunctions, and startling rates of a new scourge: low libido. All are documented in this 2016 peer-reviewed paper.

Prause & Pfaus 2015 (Viewing Sexual Stimuli Associated with Greater Sexual Responsiveness, Not Erectile Dysfunction):

Since this cobbled together paper did not identify any subjects as porn addicted, its findings cannot support the claim that the porn addiction model has been falsified. Prause & Pfaus 2015 wasn't a study at all. Instead, Prause claimed to have gathered data from four of her earlier studies, none of which addressed erectile dysfunction. Additional problem: None of the data of the Prause & Pfaus (2015) paper match the data in the four earlier studies. The discrepancies are not small and have not been explained.

A comment by researcher Richard A. Isenberg MD, published in Sexual Medicine Open Access, points out several (but not all) of the discrepancies, errors, and unsupported claims (a lay critique describes more discrepancies). Nicole Prause & Jim Pfaus made a number of false or unsupported claims associated with this paper.

Many journalists' articles about this study claimed that porn use led to better erections, yet that's not what the paper found. In recorded interviews, both Nicole Prause and Jim Pfaus falsely claimed that they had measured erections in the lab, and that the men who used porn had better erections. In the Jim Pfaus TV interview Pfaus states:

"We looked at the correlation of their ability to get an erection in the lab."

"We found a liner correlation with the amount of porn they viewed at home, and the latencies which for example they get an erection is faster."

In this radio interview Nicole Prause claimed that erections were measured in the lab. The exact quote from the show:

"The more people watch erotica at home they have stronger erectile responses in the lab, not reduced."

Yet this paper did not assess erection quality in the lab or "speed of erections." The paper only claimed to have asked guys to rate their "arousal" after briefly viewing porn (and it's not clear from the underlying papers that even that actually happened in the case of all subjects). In any case, an excerpt from the paper itself admitted that:

"No physiological genital response data were included to support men’s self-reported experience."

In a second unsupported claim, lead author Nicole Prause tweeted several times about the study, letting the world know that 280 subjects were involved, and that they had "no problems at home." However, the four underlying studies contained only 234 male subjects, so "280" is way off.

A third unsupported claim: Dr. Isenberg wondered how it could be possible for Prause & Pfaus 2015 to have compared different subjects' arousal levels when three different types of sexual stimuli were used in the 4 underlying studies. Two studies used a 3-minute film, one study used a 20-second film, and one study used still images. It's well established that films are far more arousing than photos, so no legitimate research team would group these subjects together to make claims about their responses. What's shocking is that in their paper Prause & Pfaus unaccountably claim that all 4 studies used sexual films:

"The VSS presented in the studies were all films."

This statement is false, as clearly revealed in Prause's own underlying studies.

A fourth unsupported claim: Dr. Isenberg also asked how Prause & Pfaus 2015 compared different subjects' arousal levels when only 1 of the 4 underlying studies used a 1 to 9 scale. One used a 0 to 7 scale, one used a 1 to 7 scale, and one study did not report sexual arousal ratings. Once again Prause & Pfaus inexplicably claim that:

"Men were asked to indicate their level of “sexual arousal” ranging from 1 “not at all” to 9 “extremely.”

This too is false as the underlying papers show. In summary, all the Prause-generated headlines about porn improving erections or arousal, or anything else, are unwarranted. Prause & Pfaus 2015 also claimed they found no relationship between erectile functioning scores and the amount of porn viewed in the last month. As Dr. Isenberg pointed out:

"Even more disturbing is the total omission of statistical findings for the erectile function outcome measure. No statistical results whatsoever are provided. Instead the authors ask the reader to simply believe their unsubstantiated statement that there was no association between hours of pornography viewed and erectile function. Given the authors' conflicting assertion that erectile function with a partner may actually be improved by viewing pornography the absence of statistical analysis is most egregious."

In the Prause & Pfaus response to the Dr. Isenberg critique, they once again failed to provide any data to support their "unsubstantiated statement." As this analysis documents, the Prause & Pfaus response not only evades Dr. Isenberg's legitimate concerns, it contains several new misrepresentations and several transparently false statements. Finally, a review of the literature by seven US Navy doctors commented on Prause & Pfaus 2015:

"Our review also included two 2015 papers claiming that Internet pornography use is unrelated to rising sexual difficulties in young men. However, such claims appear to be premature on closer examination of these papers and related formal criticism. The first paper contains useful insights about the potential role of sexual conditioning in youthful ED [50]. However, this publication has come under criticism for various discrepancies, omissions and methodological flaws. For example, it provides no statistical results for the erectile function outcome measure in relation to Internet pornography use. Further, as a research physician pointed out in a formal critique of the paper, the papers’ authors, “have not provided the reader with sufficient information about the population studied or the statistical analyses to justify their conclusion” [51]. Additionally, the researchers investigated only hours of Internet pornography use in the last month. Yet studies on Internet pornography addiction have found that the variable of hours of Internet pornography use alone is widely unrelated to “problems in daily life”, scores on the SAST-R (Sexual Addiction Screening Test), and scores on the IATsex (an instrument that assesses addiction to online sexual activity) [52, 53, 54, 55, 56]. A better predictor is subjective sexual arousal ratings while watching Internet pornography (cue reactivity), an established correlate of addictive behavior in all addictions [52, 53, 54]. There is also increasing evidence that the amount of time spent on Internet video-gaming does not predict addictive behavior. “Addiction can only be assessed properly if motives, consequences and contextual characteristics of the behavior are also part of the assessment” [57]. Three other research teams, using various criteria for “hypersexuality” (other than hours of use), have strongly correlated it with sexual difficulties [15, 30, 31]. Taken together, this research suggests that rather than simply “hours of use”, multiple variables are highly relevant in assessment of pornography addiction/hypersexuality, and likely also highly relevant in assessing pornography-related sexual dysfunctions."

The US Navy paper highlighted the weakness in correlating only "current hours of use" to predict porn-induced sexual dysfunctions. The amount of porn currently viewed is just one of many variables involved in the development of porn-induced ED. These may include:

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

The better way to research this phenomenon, is to remove the variable of internet porn use and observe the outcome, which was done in the Navy paper and in two other studies. Such research reveals causation instead of fuzzy correlations open to varying interpretation. My site has documented a few thousand men who removed porn and recovered from chronic sexual dysfunctions.

Landripet & Štulhofer 2015 (Is Pornography Use Associated with Sexual Difficulties and Dysfunctions among Younger Heterosexual Men? A Brief Communication):

As with Prause & Pfaus, 2015, this "Brief Communication" failed to identify any subjects as porn addicted. With no porn addicts to assess it cannot falsify the "negative consequences" of porn addiction. The Reply to Gola claimed that Landripet & Štulhofer, 2015 found no relationships between porn use and sexual problems. This is not true, as documented in both this YBOP critique and the US Navy review of the literature:

A second paper reported little correlation between frequency of Internet pornography use in the last year and ED rates in sexually active men from Norway, Portugal and Croatia [6]. These authors, unlike those of the previous paper, acknowledge the high prevalence of ED in men 40 and under, and indeed found ED and low sexual desire rates as high as 31% and 37%, respectively. In contrast, pre-streaming Internet pornography research done in 2004 by one of the paper’s authors reported ED rates of only 5.8% in men 35–39 [58]. Yet, based on a statistical comparison, the authors conclude that Internet pornography use does not seem to be a significant risk factor for youthful ED. That seems overly definitive, given that the Portuguese men they surveyed reported the lowest rates of sexual dysfunction compared with Norwegians and Croatians, and only 40% of Portuguese reported using Internet pornography “from several times a week to daily”, as compared with the Norwegians, 57%, and Croatians, 59%. This paper has been formally criticized for failing to employ comprehensive models able to encompass both direct and indirect relationships between variables known or hypothesized to be at work [59]. Incidentally, in a related paper on problematic low sexual desire involving many of the same survey participants from Portugal, Croatia and Norway, the men were asked which of numerous factors they believed contributed to their problematic lack of sexual interest. Among other factors, approximately 11%–22% chose “I use too much pornography” and 16%–26% chose “I masturbate too often” [60].

As the Navy doctors described, this paper found a pretty important correlation: Only 40% of the Portuguese men used porn "frequently," while the 60% of the Norwegians used porn "frequently." The Portuguese men had far less sexual dysfunction than the Norwegians. With respect to the Croats, Landripet & Štulhofer, 2015 acknowledge a statistically significant association between more frequent porn use and ED, but claim the effect size was small. However, this claim may be misleading according to an MD who is a skilled statistician and has authored many studies:

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

In addition, Landripet & Stulhofer 2015 omitted two significant correlations, which one of the authors presented to a European conference. He reported a significant correlation between erectile dysfunction and "preference for certain pornographic genres":

"Reporting a preference for specific pornographic genres were significantly associated with erectile (but not ejaculatory or desire-related) male sexual dysfunction."

It's telling that Landripet & Stulhofer chose to omit this significant correlation between erectile dysfunction and preferences for specific genres of porn from their paper. It’s quite common for porn users to escalate into genres that do not match their original sexual tastes, and to experience ED when these conditioned porn preferences do not match real sexual encounters. As we and the US Navy pointed out above, it’s very important to assess the multiple variables associated with porn use – not just hours in the last month, or frequency in the last year. 

The second significant finding omitted by Landripet & Stulhofer 2015 involved female participants:

"Increased pornography use was slightly but significantly associated with decreased interest for partnered sex and more prevalent sexual dysfunction among women."

A significant correlation between greater porn use and decreased libido and more sexual dysfunction seems pretty important. Why didn't Landripet & Stulhofer 2015 report that they found significant correlations between porn use and sexual dysfunction in women, as well as a few in men? And why hasn't this finding been reported in any of Stulhofer's many studies arising from these same data sets? His teams seem very quick to publish data they claim debunks porn-induced ED, yet very slow to inform women about the negative sexual ramifications of porn use.

Finally, Danish porn researcher Gert Martin Hald's formal critical comments echoed the need to assess more variables (mediators, moderators) than just frequency per week in the last 12 months:

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

Bottom line: All complex medical conditions involve multiple factors, which must be teased apart. In any case, Landripet & Stulhofer's statement that, "Pornography does not seem to be a significant risk factor for younger men's desire, erectile, or orgasmic difficulties" goes too far, since it ignores all the other possible variables related to porn use that might be causing sexual performance problems in users - including escalation to specific genres, which they found, but omitted in the "Brief Communication."

Before confidently claiming that we have nothing to worry about from internet porn, researchers still need to account for the very recent, sharp rise in youthful ED and low sexual desire, and the many studies linking porn use to sexual problems.


Claim: Religious porn users have slightly more distress about their porn use than atheists.

PRAUSE: Also, distress related to viewing sex films has been shown to be most strongly related to conservative values and religious history (Grubbs et al., 2014). This supports a social shame model of problem sex film viewing behaviors.

Here the Reply to Gola's attempt to debunk porn addiction drifts even farther from the target. What are we to make of a seemingly obvious finding that deeply religious individuals experience a bit more distress about their porn use than do atheists? How does this finding falsify the porn addiction model? It doesn't. Moreover, the study cited did not concern itself with "distress related to sex film viewing."

That said, several lay articles about the Joshua Grubbs studies ("perceived addiction studies") have tried to paint a very misleading picture of what his perceived addiction studies actually reported and what these findings mean. In response to these spurious articles, YBOP published this extensive critique of the claims made in the perceived addiction studies and in the related misleading articles.

Grubbs et al., 2014 (Transgression as Addiction: Religiosity and Moral Disapproval as Predictors of Perceived Addiction to Pornography):

The reality of this study:

  1. This study failed to identify who was and was not a porn addict, so it's not relevant to assessing the porn addiction model.
  2. Contrary to the Reply to Gola's assertion above, this study was not concerned with "distress related to sex film viewing." The word "distress" is not in the study's abstract.
  3. Contrary to the Reply to Gola and the Grubbs et al., 2014 conclusion, the strongest predictor of porn addiction was actually hours of porn use, not religiosity! See this extensive section with the study's tables, the correlations, and what the study actually found. 
  4. When we break down the Grubbs's porn addiction questionnaire (CPUI-9), the relationship between "religiosity" and the core addiction behaviors (Access Efforts questions 4-6) is virtually non-existent. Put simply: religiosity has next to nothing to do with actual porn addiction.
  5. On the other hand, a very strong relationship exists between "hours of porn use" and the core addiction behaviors as assessed by the "Access Efforts" questions 4-6. Put simply: Porn addiction is very strongly related to amount of porn viewed.

The Reply to Gola, bloggers like David Ley, and even Grubbs himself, seem to be endeavoring to construct a meme that religious shame is the "real" cause of porn addiction. Yet it's simply not true that the "perceived addiction" studies are evidence of this trendy talking point. Again, this extensive analysis debunks the "porn addiction is only religious shame" claim. The meme crumbles when we consider that:

  1. Religious shame doesn't induce brain changes that mirror those found in drug addicts. In contrast, there are now 33 neurological studies reporting addiction-related brain changes in compulsive porn users/sex addicts.
  2. The perceived addiction studies did not use a cross-section of religious individuals. Instead, only current porn users (religious or nonreligious) were questioned. All cross-sectional studies report far lower rates of compulsive sexual behavior and porn use in religious individuals (study 1, study 2, study 3, study 4, study 5, study 6, study 7, study 8,).
    • This means Grubbs's sample of "religious porn users" is relatively tiny and inevitably skewed towards individuals with pre-existing conditions or underlying issues.
    • It also means that "religiosity" does not predict porn addiction. Instead, religiosity apparently protects one from developing a porn addiction.
  3. Many atheists and agnostics develop porn addiction. Two 2016 studies on men who had used porn in the last the last 6 months, or in the last 3 months, reported extraordinarily high rates of compulsive porn use (28% for both studies).
  4. Being religious doesn't induce chronic erectile dysfunction, low libido and anorgasmia in healthy young men. Yet numerous studies link porn use to sexual dysfunctions and lower sexual satisfaction, and ED rates have inexplicably skyrocketed by 1000% in men under 40 since "tube" porn captured porn viewers' attention beginning at the end of 2006.
  5. This 2016 study on treatment-seeking porn addicts found that religiosity did not correlate with negative symptoms or scores on a sex addiction questionnaire. This 2016 study on treatment-seeking hypersexuals found no relationship between religious commitment and self-reported levels of hypersexual behavior and related consequences.
  6. Research shows that as the severity of their porn addiction increases, religious individuals often return to religious practices, attend church more often, and become more devout as a way of coping/seeking recovery (think 12 Steps). This alone could account for any relationship between porn addiction and religiosity.

In summary:

  • Both the Reply to Gola assertion and the single study cited have nothing to with the porn addiction model.
  • The 2014 Grubbs "perceived addiction" study actually found porn addiction was more strongly correlated with the amount of porn viewed than with religiosity.
  • There's no evidence that religious "shame" induces addiction-related brain changes, and yet these changes have repeatedly been found in problematic porn users' brains.
  • There's much evidence that religiosity actually protects individuals from porn use and thus porn addiction.
  • Grubbs's sample of "religious porn users" is not cross-sectional, and therefore inevitably skewed towards higher rates of genetic predispositions or underlying issues.
  • Two recent studies reported no relationship between porn addiction and religiosity in men seeking treatment.

SECTION TWO: Critique of a Few Selected Claims

Introduction

In this section we examine a few of the unsupported assertions and false statements put forth in the Reply to Gola. While it's tempting to challenge the Reply to Gola line by line, its major weakness is that its arguments are specious. They fail to address the content of the YBOP critique or the 6 peer-reviewed analyses of Prause et al. 2015 (including Matuesz Gola's): 1, 2, 3, 4, 5, 6. All 6 expert analyses agree that Prause et al., 2015 actually found desensitization or habituation, which is consistent with the addiction model.

The following assertions of the Reply to Gola relate to Mateusz Gola's concerns about the Prause et al., 2015 methodological flaws. Several major flaws in this and the other Prause Studies leave any study results and associated claims in serious doubt:

  1. Subjects were not screened for porn addiction (potential subjects only answered a single question).
  2. Questionnaires used did not ask about porn use and were not valid for assessing "porn addiction."
  3. Subjects were heterogeneous (males, females, non-heterosexuals).
  4. Subjects were not screened for confounding psychiatric conditions, drug use, psychotropic medications, drug addictions, behavioral addictions, or compulsive disorders (any single one of which is exclusionary).

Reply To Claim: Prause et al., 2015 employed "proper" methodology in recruiting and identifying which subjects were porn addicts and Voon et al., 2014 did not.

Nothing could be further from the truth, as the Prause et al. methodology failed on every level, while Voon et al. employed meticulous methodology in the recruitment, screening and assessment of its "porn addicted" subjects (Compulsive Sexual Behaviors subjects).

A little background. Prause compared the average EEG readings of 55 "porn addicts" to the average EEG readings of 67 "non-addicts." Yet the validity of Prause et al., 2015 would be entirely dependent on comparing the brain activation patterns of a group of porn addicts to a group of non-addicts. For Prause's claims of falsification and the resulting dubious headlines to be legitimate, all of Prause's 55 subjects would have to have been actual porn addicts. Not some, not most, but every single subject (as Voon's were). All signs point to a good number of the 55 Prause subjects being non-addicts. An excerpt from Steele et al., 2013 describes the entire selection process and exclusion criteria employed in the 3 Prause Studies (Prause et al., 2013Steele et al., 2013, Prause et al., 2015):

"Initial plans called for patients in treatment for sexual addiction to be recruited, but the local Institutional Review Board prohibited this recruitment on the grounds that exposing such volunteers to VSS could potentiate a relapse. Instead, participants were recruited from the Pocatello, Idaho community by online advertisements requesting people who were experiencing problems regulating their viewing of sexual images."

That's it. The only criterion for inclusion was answering yes to a single question: "Are you experiencing problems regulating your viewing of sexual images." The first noticeable error involves the screening question used, which asks only about viewing sexual images, and not about viewing internet porn, especially streaming videos (which appear to be the form of porn causing the most severe symptoms).

A much bigger flaw is that the Prause Studies did not screen potential subjects by using a sex or porn addiction questionnaire (as Voon et al. did). Nor were potential subjects asked whether porn use had negatively affected their lives, whether they considered themselves addicted to porn, or whether they experienced addiction-like symptoms (as Voon et al. did).

Make no mistake, neither Steele et al., 2013 nor Prause et al., 2015 described these 55 subjects as porn addicts or compulsive porn users. The subjects only admitted to feeling "distressed" by their porn use. Confirming the mixed nature of her subjects, Prause admitted in 2013 interview that some of the 55 subjects experienced only minor problems (which means they were not porn addicts):

"This study only included people who reported problems, ranging from relatively minor to overwhelming problems, controlling their viewing of visual sexual stimuli."

Compounding the failure to screen subjects for actual porn addiction, the 3 Prause Studies chose to ignore standard exclusion criteria normally employed in addiction studies to prevent confounds. The Prause Studies did not:

  • Screen subjects for psychiatric conditions (an automatic exclusion)
  • Screen subjects for other addictions (an automatic exclusion)
  • Ask subjects if they were using psychotropic medications (often exclusionary)
  • Screen subjects for those currently using drugs (automatic exclusion)

Voon et al., 2014 did all the above and much more to ensure they were investigating only homogeneous, porn addicted subjects. Yet Prause et al., 2015 admitted they employed no criteria for excluding subjects:

"As hypersexuality is not a codified diagnosis and we were expressly prohibited from recruiting patients, no thresholds could be used to empirically identify problem users"

It appears that in Prause's view simply answering the single-question ad met the exclusion criteria for the Prause Studies. This brings us to Matuesz Gola's concern about Prause's subjects not being porn addicts, as they only viewed an average of 3.8 hours of porn per week, while Voon's subjects viewed 13.2 hours per week:

Mateusz Gola: "It is worthy to notice that in Prause et al. (2015) problematic users consume pornography in average for 3.8 h/week it is almost the same as non-problematic pornography users in Kühn and Gallinat (2014) who consume in average 4.09 h/week. In Voon et al. (2014) non-problematic users reported 1.75 h/week and problematic 13.21 h/week (SD = 9.85) – data presented by Voon during American Psychological Science conference in May 2015."

The hours of porn use per week for each study:

  • Voon et al: 13.2 hours (all were porn addicts)
  • Kuhn & Gallinat: 4.1 hours (none were classified as porn addicts)
  • Prause et al: 3.8 hours (no one knows)

Gola also pondered how Prause's 55 subjects could possibly be porn addicts (for purpose of "falsifying porn addiction") when they watched less porn than the Kühn & Gallinat, 2014 non-addicts. How in the world can all of the Prause subjects be "porn addicts" when none of the Kühn & Gallinat subjects are porn addicts? However they are labeled, subjects have to be comparable across studies before you can claim to have "falsified" competing research. This is elementary science procedure.

So, how did Prause & company address the many gaping holes in their subjects' recruitment and assessment process? By attacking the meticulous methodology of Voon et al., 2014! First, the description of recruitment process, assessment criteria for porn addiction, and exclusion criteria excerpted from Voon et al., 2014 (also see Schmidt et al., 2016 & Banca et al., 2016):

"CSB subjects were recruited via internet-based advertisements and from referrals from therapists. Age-matched male HV were recruited from community-based advertisements in the East Anglia area. All CSB subjects were interviewed by a psychiatrist to confirm they fulfilled diagnostic criteria for CSB (met proposed diagnostic criteria for both hypersexual disorder [Kafka, 2010; Reid et al., 2012] and sexual addiction [Carnes et al., 2007]), focusing on compulsive use of online sexually explicit material. This was assessed using a modified version of the Arizona Sexual Experiences Scale (ASES) [Mcgahuey et al., 2011], in which questions were answered on a scale of 1–8, with higher scores representing greater subjective impairment. Given the nature of the cues, all CSB subjects and HV were male and heterosexual. All HV were age-matched (±5 years of age) with CSB subjects. Subjects were also screened for compatibility with the MRI environment as we have done previously [Banca et al., 2016; Mechelmans et al., 2014; Voon et al., 2014]. Exclusionary criteria included being under 18 years of age, having a history of SUD, being a current regular user of illicit substances (including cannabis), and having a serious psychiatric disorder, including current moderate-severe major depression or obsessive-compulsive disorder, or history of bipolar disorder or schizophrenia (screened using the Mini International Neuropsychiatric Inventory) [Sheehan et al., 1998]. Other compulsive or behavioral addictions were also exclusions. Subjects were assessed by a psychiatrist regarding problematic use of online gaming or social media, pathological gambling or compulsive shopping, childhood or adult attention deficit hyperactivity disorder, and binge-eating disorder diagnosis. Subjects completed the UPPS-P Impulsive Behavior Scale [Whiteside and Lynam, 2001] to assess impulsivity, and the Beck Depression Inventory [Beck et al., 1961] to assess depression. Two of 23 CSB subjects were taking antidepressants or had comorbid generalized anxiety disorder and social phobia (N = 2) or social phobia (N = 1) or a childhood history of ADHD (N = 1). Written informed consent was obtained, and the study was approved by the University of Cambridge Research Ethics Committee. Subjects were paid for their participation."

"Nineteen heterosexual men with CSB (age 25.61 (SD 4.77) years) and 19 age-matched (age 23.17 (SD 5.38) years) heterosexual male healthy volunteers without CSB were studied (Table S2 in File S1). An additional 25 similarly aged (25.33 (SD 5.94) years) male heterosexual healthy volunteers rated the videos. CSB subjects reported that as a result of excessive use of sexually explicit materials, they had lost jobs due to use at work (N = 2), damaged intimate relationships or negatively influenced other social activities (N = 16), experienced diminished libido or erectile function specifically in physical relationships with women (although not in relationship to the sexually explicit material) (N = 11), used escorts excessively (N = 3), experienced suicidal ideation (N = 2) and using large amounts of money (N = 3; from £7000 to £15000). Ten subjects either had or were in counselling for their behaviours. All subjects reported masturbation along with the viewing of online sexually explicit material. Subjects also reported use of escort services (N = 4) and cybersex (N = 5). On an adapted version of the Arizona Sexual Experiences Scale [43], CSB subjects compared to healthy volunteers had significantly more difficulty with sexual arousal and experienced more erectile difficulties in intimate sexual relationships but not to sexually explicit material (Table S3 in File S1)."

The Reply to Gola excerpt attacking Voon et al., 2014:

"Gola notes that hours of film consumption appeared lower in our participants than in two other studies of problem erotica use. We pointed this out in our paper (paragraph beginning “The problem group reported significantly more…”). Gola argues that our sample of problem users reported fewer hours of sex film viewing than the problem sample from Voon et al. (2014). However, Voon et al. specifically recruited for participants high in sexual shame, including advertisements on shame-based websites about sex-film use, “treatment-seeking” men despite “porn” use not being recognized by the DSM-5, and with funding by a television show framed as the “harms” of “porn”. Those who adopt addiction labels have been shown to have a history of socially conservative values and high religiosity (Grubbs, Exline, Pargament, Hook, & Carlisle, 2014). It is more likely that the Voon et al. (2014) sample is characterized by high sexual shame in online communities that encourage reporting of high use. Also, “porn” use was assessed during a structured interview, not a standardized questionnaire. Thus, the psychometrics and implicit biases inherent in a structured interview are unknown. This makes it difficult to compare sex film use measures between studies. Our strategy for identifying groups is consistent with widely-cited work demonstrating the importance of distress criterion in sexual difficulties (Bancroft, Loftus, & Long, 2003)."

This is nothing more than a web of easily debunked false statements and unwarranted claims calculated to divert the reader's attention away from Prause's deficient screening process. We start with:

Reply to Gola: However, Voon et al. specifically recruited for participants high in sexual shame, including advertisements on shame-based websites about sex-film use, “treatment-seeking” men despite “porn” use not being recognized by the DSM-5, and with funding by a television show framed as the “harms” of “porn.”

First, the Reply to Gola supplies no evidence to support the claim that participants experienced "high sexual shame" or were recruited from so-called "shame based websites." This is nothing more than baseless propaganda. On the other hand, the Prause Studies recruited subjects from Pocatello, Idaho which is over 50% Mormon. It's very likely that Prause's religious subjects experienced shame or guilt in relationship to their porn use, in contrast to Voon's subjects recruited publicly in the UK.

Second, many of Voon's participants were seeking treatment for porn addiction and referred by therapists. What better way is there to ensure porn-addicted subjects? It's very odd that the Reply to Gola would spin this as a negative (rather than an unarguable strength), when the Prause Studies wanted to use only "treatment seeking" sex addicts, but were prohibited by the university review board. Taken from the first Prause EEG study:

Steele et al., 2013: "Initial plans called for patients in treatment for sexual addiction to be recruited, but the local Institutional Review Board prohibited this recruitment on the grounds that exposing such volunteers to VSS could potentiate a relapse."

Third, the Reply to Gola stoops to an outright lie by claiming that Voon et al. 2014 was funded by a "television show." As clearly stated in Voon et al., 2014, the study was funded by "Wellcome Trust":

Voon et al., 2014: "Funding: Funding provided by Wellcome Trust Intermediate Fellowship grant (093705/Z/10/Z). Dr. Potenza was supported in part by grants P20 DA027844 and R01 DA018647 from the National Institutes of Health; the Connecticut State Department of Mental Health and Addiction Services; the Connecticut Mental Health Center; and a Center of Excellence in Gambling Research Award from the National Center for Responsible Gaming. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript."

This is followed by more false and misleading statements. For example, the Reply to Gola throws in another untruth about the Voon et al. recruitment/assessment methodology:

Reply to Gola: Also, “porn” use was assessed during a structured interview, not a standardized questionnaire.

False. In screening potential subjects Voon et al., 2014 used four standardized questionnaires and employed an extensive psychiatric interview. The following is a shortened description of the screening process taken from Banca et al., 2016 (CSB is Compulsive Sexual Behaviors):

Voon et al., 2014: CSB subjects were screened using the internet sex screening test (ISST; Delmonico and Miller, 2003) and an exhaustive experimenter-designed questionnaire which included items pertaining to age of onset, frequency, duration, attempts to control use, abstinence, patterns of use, treatment and negative consequences. CSB participants were interviewed by a psychiatrist to confirm they fulfilled two sets of diagnostic criteria for CSB (proposed diagnostic criteria for Hypersexual Disorder; criteria for sexual addiction; Carnes et al., 2001; Kafka, 2010; Reid et al., 2012), focusing on compulsive use of online sexually explicit material.  These criteria emphasize failure to cut down or control sexual behaviors, including consumption of pornography, despite social, financial, psychological and academic or vocational problems. Detailed description of CSB symptoms are described in Voon et al. (2014).

It's shocking that the Reply to Gola would dare to compare the virtually nonexistent screening procedure used in the Prause Studies (subjects answered a single-question advertisement) with the exhaustive, expert screening procedures used for Voon et al., 2014:

  1. Internet Sex Screening Test, Delmonico and Miller, 2003
  2. Interviewed by a psychiatrist who used criteria for sexual addiction from the 3 most widely used questionnaires: Carnes et al., 2001; Kafka, 2010; Reid et al., 2012)
  3. Extensive investigator-designed questionnaire on details including age of onset, frequency, duration, attempts to control use, abstinence, patterns of use, treatment and negative consequences.

Incidentally, this process was merely the screening to confirm the existence of porn addiction; Voon et al. didn't stop there. More questionnaires and interviews excluded those with psychiatric conditions, drug or behavioral addictions, OCD or compulsive disorders, and current or past substance abusers. The researchers in the Prause Studies did none of this.

Finally, the Reply to Gola regurgitates the unsupported claim that porn addiction is nothing more than religious shame,

Reply to Gola: "Those who adopt addiction labels have been shown to have a history of socially conservative values and high religiosity (Grubbs, Exline, Pargament, Hook, & Carlisle, 2014)."

The claimed correlation between porn addiction and religiosity was addressed above and thoroughly debunked in this extensive analysis of the Joshua Grubbs material.


Reply to Gola evades serious flaw in Prause et al., 2015: Unacceptable diversity of subjects

Critiques of Nicole Prause's controversial EEG studies (Steele et al., 2013, Prause et al., 2015) have raised grave concerns about the diverse nature of the "distressed" porn using subjects. The EEG studies included males and females, heterosexuals and non-heterosexuals, yet the researchers showed them all standard, possibly uninteresting, male+female porn. This matters, because it violates standard procedure for addiction studies, in which researchers select homogeneous subjects in terms of age, gender, orientation, even similar IQ's (plus a homogeneous control group) in order to avoid distortions caused by such differences.

In other words, the results of the 2 EEG studies were dependent on the premise that males, females, and non-heterosexuals are no different in their brain responses to sexual images. Yet study after study confirms that males and female have significantly different brain responses to sexual images or films. Gola knew this and mentioned this fatal flaw in a note: 

Mateusz Gola: "It is worthy to notice that the authors present results for male and female participants together, while recent studies shows that sexual images ratings of arousal and valence differs dramatically between genders (see: Wierzba et al., 2015)."

In an evasive maneuver, the Reply to Gola ignores this elephant in the room: Male and female brains respond quite differently to sexual imagery. Instead, the Reply to Gola informs us that both men and women become aroused by sexual imagery, and other irrelevant fun facts:

"Gola claims that data for men and women should not be presented together, because they do not respond to the same sexual stimuli. Actually, men and women’s preferences for sexual stimuli overlap heavily (Janssen, Carpenter, & Graham, 2003). As we described, the images were pretested to equate subjective sexual arousal in both men and women. “Sexual” images from the International Affective Picture System were supplemented, because they are processed as romantic rather than sexual by both men and women (Spiering, Everaerd, & Laan, 2004). More importantly, research has shown that differences in sexual arousal ratings attributed to gender are better understood as attributable to sexual drive (Wehrum et al., 2013). Since sexual desire was a predictor in the study, it was not appropriate to segment the sexual arousal reports by the known confound: gender."

The above response has nothing to do with Mateusz Gola's criticism: When viewing the exact same porn male and female brains exhibit very different brain wave (EEG) and blood flow (fMRI) patterns. For example, this EEG study found that women had far higher EEG readings than men when viewing the same sexual pictures. You can't average together male and female EEG readings, as the Prause Studies did, and end up with anything meaningful. Nor can you compare the brain responses of a mixed group to the brain responses of another mixed group, as the Prause Studies did.

There's a reason why none of the published neurological studies on porn users (except for Prause's) mixed males and females. Every single neurological study involved subjects who were all the same sex and same sexual orientation. Indeed, Prause herself stated in an earlier study (2012) that individuals vary tremendously in their response to sexual images:

"Film stimuli are vulnerable to individual differences in attention to different components of the stimuli (Rupp & Wallen, 2007), preference for specific content (Janssen, Goodrich, Petrocelli, & Bancroft, 2009) or clinical histories making portions of the stimuli aversive (Wouda et al., 1998)."

"Still, individuals will vary tremendously in the visual cues that signal sexual arousal to them (Graham, Sanders, Milhausen, & McBride, 2004)."

A 2013 Prause study stated:

"Many studies using the popular International Affective Picture System (Lang, Bradley, & Cuthbert, 1999) use different stimuli for the men and women in their sample."

Large variations are to be expected with a sexually diverse group of subjects (males, females, non-heterosexuals), rendering comparisons and conclusions of the type made in the Prause Studies unreliable.

A collection of studies confirming that male and female brains respond very differently to the same sexual imagery:

In summary, the Prause Studies suffered from serious methodological flaws that call into question the studies' results and the authors' claims about "falsifying" the porn addiction model:

  1. Subjects were heterogeneous (males, females, non-heterosexuals)
  2. Subjects were not screened for porn addiction, mental disorders, substance use, or drug and behavioral addictions
  3. Questionnaires were not validated for porn addiction or porn use