Neurobiology of Compulsive Sexual Behavior: Emerging Science (2016)
COMMENTS: While this paper is only a brief summation, it contains a few key observations. For example, it states that both Prause et al., 2015 and Kuhn & Gallinat, 2014 report a similar finding: greater porn use correlating with greater habituation to porn. Both studies reported lower brain activation in response to brief exposure to photos of vanilla porn. In the following excerpt "Lower late positive-potential" refers to the EEG findings of Prause et al.:
"In contrast, studies in healthy individuals suggest a role for enhanced habituation with excessive use of pornography. In healthy men, increased time spent watching pornography correlated with lower left putaminal activity to pornographic pictures (Kühn and Gallinat, 2014). Lower late positive-potential activity to pornographic pictures was observed in subjects with problematic pornography use."
Why is this important? Lead author Nicole Prause claimed that her single EEG study debunked "porn addiction". This is the second peer-reviewed paper to reject Prause's interpretations. Here's the first paper.
Neuropsychopharmacology 41, 385-386 (January 2016) | doi:10.1038/npp.2015.300
Shane W Kraus 1, 2, Valerie Voon 3, and Marc N Potenza 2, 4
1 VISN 1 Mental Illness Research Education and Clinical Centers, VA Connecticut Healthcare System, West Haven, CT, USA; 2 Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA;
3 Department of Psychiatry, University of Cambridge, Cambridge, UK;
4 Department of Neurobiology, Child Study Center and CASA Columbia, Yale University School of Medicine, New Haven, CT, USA
Compulsive sexual behavior (CSB) is characterized by craving, impulsivity, social/occupational impairment, and psychiatric comorbidity. Prevalence of CSB is estimated around 3–6%, with a male predominance. Although not included in DSM-5, CSB can be diagnosed in ICD-10 as an impulse control disorder. However, debate exists about CSB’s classification (eg, as an impulsive-compulsive disorder, a feature of hypersexual disorder, an addiction, or along a continuum of normative sexual behavior).
Preliminary evidence suggests that dopamine may contribute to CSB. In Parkinson’s disease (PD), dopamine replacement therapies (Levo-dopa, dopamine agonists) have been associated with CSB and other impulse control disorders (Weintraub et al, 2010). A small number of case studies using naltrexone support its effectiveness at reducing urges and behaviors associated with CSB (Raymond et al, 2010), consistent with the possible opioidergic modification of mesolimbic dopamine function in reducing CSB. Currently, larger, adequately powered, neurochemical investigations and medication trials are needed to further understand CSB.
Incentive motivational processes relate to sexual cue reactivity. CSB vs non-CSB men had greater sex-cuerelated activation of the anterior cingulate, ventral striatum, and amygdala (Voon et al, 2014). In CSB subjects, functional connectivity of this network associated with cue-related sexual desire, thus resonating with findings in drug addictions (Voon et al, 2014). CSB men further show enhanced attentional bias to pornographic cues, implicating early attentional orienting responses as in addictions (Mechelmans et al, 2014). In CSB vs non-CSB PD patients, exposure to pornographic cues increased activation in the ventral striatum, cingulate and orbitofrontal cortex, linking also to sexual desire (Politis et al, 2013). A small diffusion-tensor imaging study implicates prefrontal abnormalities in CSB vs non-CSB men (Miner et al, 2009).
In contrast, studies in healthy individuals suggest a role for enhanced habituation with excessive use of pornography. In healthy men, increased time spent watching pornography correlated with lower left putaminal activity to pornographic pictures (Kühn and Gallinat, 2014). Lower late positive- potential activity to pornographic pictures was observed in subjects with problematic pornography use. These findings, while contrasting, are not incompatible. Habituation to picture cues relative to video cues may be enhanced in healthy individuals with excessive use; whereas, CSB subjects with more severe/pathological use may have enhanced cue reactivity.
Although recent neuroimaging studies have suggested some possible neurobiological mechanisms of CSB, these results should be treated as tentative given methodological limitations (eg, small sample sizes, cross-sectional designs, solely male subjects, and so on). Current gaps in research exist complicating definitive determination whether CSB is best considered as an addiction or not. Additional research is needed to understand how neurobiological features relate to clinically relevant measures like treatment outcomes for CSB. Classifying CSB as a ‘behavioral addiction’ would have significant implications for policy, prevention and treatment efforts; however, at this time, research is in its infancy. 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.
- Kühn S, Gallinat J (2014). Brain structure and functional connectivity associated with pornography consumption: the brain on porn. JAMA Psychiatry 71: 827–834.
- Mechelmans DJ, Irvine M, Banca P, Porter L, Mitchell S, Mole TB et al (2014). Enhanced attentional bias towards sexually explicit cues in individuals with and without compulsive sexual behaviours. PloS One 9: e105476.
- Miner MH, Raymond N, Mueller BA, Lloyd M, Lim KO (2009). Preliminary investigation of the impulsive and neuroanatomical characteristics of compulsive sexual behavior. Psychiatry Res 174: 146–151.
- Politis M, Loane C, Wu K, O’Sullivan SS, Woodhead Z, Kiferle L et al (2013). Neural response to visual sexual cues in dopamine treatment-linked hypersexuality in Parkinson’s disease. Brain 136: 400–411.
- Raymond NC, Grant JE, Coleman E (2010). Augmentation with naltrexone to treat compulsive sexual behavior: a case series. Ann Clin Psychiatry 22: 55–62.
- Voon V, Mole TB, Banca P, Porter L, Morris L, Mitchell S et al (2014). Neural correlates of sexual cue reactivity in individuals with and without compulsive sexual behaviours. PloS One 9: e102419.
- Weintraub D, Koester J, Potenza MN, Siderowf AD, Stacy M, Voon V et al (2010). Impulse control disorders in Parkinson disease: a cross-sectional study of 3090 patients. Arch Neurol 67: 589–595. Neuropsychopharmacology Reviews (2016) 41, 385–386; doi:10.1038/npp.2015.300