Decades of studies from respected academic institutions, have demonstrated significant impacts of porn consumption for individuals, relationships, and society. "What’s the Research" aims to shed light on the expanding field of academic resources that showcase porn’s harms in a variety of ways. Below are selected excerpts from published studies on this issue.
The full study can be accessed here.
Can pornography be addictive? An fMRI study of men seeking treatment for problematic pornography use.
Authors: Mateusz, Gola; Małgorzata, Wordecha; Guillaume, Sescousse; Michal, Lew-Starowicz; Bartosz, Kossowski; Marek, Wypych; Scott, Makeig; Marc, Potenza; and Artur, Marchewka.
Published: September 2017
Peer-Reviewed Journal: Neuropsychopharmacology, Vol 42(10), Sep. 2017. pp. 2021-2031.
Background
Pornography consumption has become highly prevalent, in part because of nearly universal Internet availability. Approximately 70% of males and 20% of females aged 18-30 years use pornography weekly (Hald, 2006). Among teenagers, less than 18 years of age, 90% of boys and 60% of girls have used Internet pornography (Sabina et al, 2008), with 12% of children having onset of regular consumption below age 12 (Opinium Research, 2014). For most people, pornography viewing is a form of entertainment, but for some individuals, problematic pornography use (PPU) accompanied by excessive masturbation promotes seeking of treatment (Gola et al, 2016a). Such observations raise multiple scientifically and clinically important questions, including with respect to brain mechanisms related to PPU and their relationships to clinically relevant measures. Given the negative health measures associated with compulsive sexual behavior (CSB) broadly (e.g., childhood sexual trauma and post-traumatic stress disorder (Smith et al, 2014)), more research is needed in order to better understand specific forms of CSB like PPU and develop improved intervention strategies.
The existence and clinical utility of non-substance or behavioral addictions have been debated, with gambling disorder currently being the sole non-substance disorder classified together with substance-use disorders in DSM-5 (American Psychiatric Association, 2013; Holden, 2001). Although a field trial for hypersexual disorder (Kafka, 2010) was conducted, neither this condition or related behaviors such as PPU were included in DSM-5, in part given the relative paucity of data on these behaviors or conditions (Kafka, 2014; Krueger, 2016; Reid et al, 2012). Whether excessive and problematic patterns of sexual behavior are best conceptualized within obsessive-compulsive disorder (OCD), impulse-control-disorder (ICD), behavioral-addiction or other frameworks has been debated (Kafka, 2014; Kor et al, 2013; Kraus et al, 2016). A recent case series reported that low dose (20 mg/day) of paroxetine treatment (found to be successful in treating OCD (Stein et al, 2007)) led to reductions in anxiety and severity of PPU (Gola and Potenza, 2016). Additionally, naltrexone treatment (found to be successful in alcohol-use (Maisel et al, 2013) and gambling disorders (Yip and Potenza, 2014) may be helpful for individuals with PPU (Bostwick and Bucci, 2008; Kraus et al, 2015).
As naltrexone has been proposed to reduce craving through modulating activity in mesolimbic structures (Thompson et al, 2000), the ventral striatum may contribute importantly to compulsive sexual behaviors including PPU. Recent MRI studies of men support this hypothesis. Among non-problematic pornography users, an inverse relationship between right caudate volume and frequency of pornography consumption was observed (Kühn and Gallinat, 2014). Increased blood-oxygen-level-dependent (BOLD) responses in the ventral striatum were observed in response to preferred sexual pictures when compared to non-preferred ones, and this activity positively correlated with scores on the Internet Addiction Test Modified for Cybersex (Brand et al, 2016). Men with CSB (meeting criteria for hypersexual disorder (Kafka, 2010)) as compared to those without
(comparison subjects; CSubs) demonstrated increased striatal reactivity for sexually explicit videos (Voon et al, 2014) and decreased functional connectivity between the ventral striatum and prefrontal cortex (Klucken et al, 2016). These findings suggest similarities between CSB and addictions.
The current study sought to extend prior studies by examining the neural correlates of sexual and non-sexual images in men seeking treatment for PPU and men without PPU. We further sought to relate the brain activations to clinically relevant features of PPU. No prior neuroimaging studies have examined individuals seeking treatment for PPU. Additionally, as it is important to investigate possible common neural mechanisms of addictions, we investigated cue-induced “wanting” of “addiction-related” reward dissociated from “liking” aspects. Most studies using visual sexual stimuli do not allow for determination of whether stimuli may represent cues or rewards (Gola, 2016; Gola et al, 2016c) and very rarely permit comparisons to other incentives, making it difficult to interpret results with respect to the IST (Berridge, 2012; Gola et al, 2016d; Robinson and Berridge, 1993; Robinson et al, 2015).
Methods
Fifty-seven heterosexual males (age range 18-48 years) participated in the fMRI study. These included thirty-one men seeking treatment for PPU (meeting criteria of hypersexual disorder (Kafka,2010)) and without other psychiatric diagnoses and twenty-six CSubs with comparable ages and incomes, also without psychopathology. All subjects were medication-free. All subjects provided written informed consent.
To investigate, we used an incentive delay task (Figure 1) previously used in studies of gambling disorder (Sescousse et al, 2013). This task has three important properties; it: 1) disentangles cue- and reward-related phases related to anticipation and outcome, respectively; 2) allows measurement of neural and behavioral indicators of ‘wanting’ (in a cue phase) and ‘liking’ (in a reward phase); and, 3) provides a possibility to compare “addiction-related” stimuli (in this case erotic pictures) with another potent reward (monetary gains). As individuals with gambling disorder expressed higher ventral striatal responses to monetary as compared to erotic cues in the cue phase (Sescousse et al, 2013), we hypothesized that men with PPU as compared to those without would demonstrate increased ventral striatal responses for erotic but not monetary cues. We further hypothesized that the degree of ventral striatal activation to erotic cues in the men with PPU would correlate positively with severity of PPU, amount of pornography consumed and frequency of masturbation. Finally, according to the IST, we hypothesized that ‘wanting’ in the erotic cue phase would be associated with ‘liking’ in the reward phase in the CSub group but not the PPU group, representing a dissociation between ‘wanting’ and ‘liking’ in PPU.
Results
Our findings suggest that, similar to what is observed in substance and gambling addictions, the neural and behavioral mechanisms associated with the anticipatory processing of cues specifically predicting erotic rewards relate importantly to clinically relevant features of 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.
Our results, in line with the IST (Berridge, 2012; Gola et al, 2016d; Robinson and Berridge, 1993; Robinson et al, 2015), indicate that men seeking treatment for PPU when compared to CSubs show increased ventral striatal reactivity for cues predicting erotic pictures (but not for cues predicting monetary gains). Such increased striatal reactivity for cues predicting erotic content is followed by higher motivation (reflected in shorter RTs) to view erotic rewards (Figure 2d, 2a and 4a). Consistent with the IST (Robinson and Berridge, 1993; Robinson et al, 2015), these results suggest increased ‘wanting’ evoked specifically by an initially neutral cue predictive for erotic rewards. Also as predicted by the IST, a neural indicator of ‘wanting’ (BOLD response in the ventral striatum) is dissociated from measures of ‘liking’ among PPU men but not CSubs, and this was reflected in three-way interactions between incentives (monetary versus erotic), group (CSubs versus PPU), and experimental phase (cue versus reward). In other words, subjects who seek treatment for PPU expressed higher motivational behavior for pornography cues predictive of erotic content. This motivated behavior (‘wanting’, probably related to the expectation of highly rewarding value of pornography) is dissociated from actual ‘liking’: PPU subjects did not differ from CSubs in BOLD response for erotic pictures (reward phase) or hedonic values ratings (Figure 2c and 2e). Moreover, the differential striatal reactivity to erotic versus monetary cues (but not rewards) was related not only to indicators of motivated behaviors during the study, but also to the severity of CSB, amount of pornography consumption and frequency of masturbation reported during the 2 months preceding fMRI.
This pattern of increased cue-related ‘wanting’ dissociated from reward-related ‘liking’ resembles findings in addictions (Robinson et al, 2015); (Sescousse et al, 2013). Specific cues (predictive for addiction-related rewards) evoke activations of brain-reward systems associated with striatal responses (Flagel et al, 2011; Oei et al, 2012; Robinson and Berridge, 1993; Smith et al, 2011) and motivations to approach rewards, but experienced hedonic value (Berridge, 2012; Robinson et al, 2015) or striatal response for reward (Flagel et al, 2011) are not proportional to ones evoked by the preceding cue.
These findings are consistent with an impaired mechanism of updating cue-related predictions about expected values of erotic stimuli, similar to mechanisms proposed for substance-use disorders (Parvaz et al, 2015; Tanabe et al, 2013), although this possibility warrants direct investigation. Given the role of the ventral striatum in reward anticipation (Balodis and Potenza, 2015), initially neutral stimuli (akin to cues introduced in our experimental procedure) may become for men with PPU powerful incentives under the circumstances of pairing them with erotic images. Our results show that individuals with PPU are much more sensitive (then CSubs) for cues signaling erotic rewards and the magnitude of the expected erotic reward further modulates the ventral striatal reactivity in men with PPU, which does not happen among CSubs.