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-cue-related 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.

FUNDING AND DISCLOSURE

This study was funded by support from the Department of Veterans Affairs, VISN 1 Mental Illness Research Education and Clinical Center, the National Center for Responsible Gaming, and CASAColumbia. MNP has received financial support or compensation for the following: has acted as consultant and/or advisor for Somaxon, Boehringer Ingelheim, Lundbeck, Ironwood, Shire, INSYS, and RiverMend Health; has received research support from the National Institutes of Health, Veterans Administration, Mohegan Sun Casino, the National Center for Responsible Gaming, Forest Laboratories, Ortho-McNeil, Oy-Contral Pharma/Biotie Therapies, GlaxoSmithKline, and Psyadon Pharmaceuticals; has participated in surveys, mailings or telephone consultations related to drug addiction, impulse-control disorders, and other health topics; has consulted for gambling and legal entities on issues related to impulse-control disorders; provided clinical care in the Connecticut Department of Mental Health and Addiction Services Problem Gambling Services Program; has performed grant reviews for the National Institutes of Health and other agencies; has been an editor for journal sections and journals; has given academic lectures in grand rounds, CME events, and other clinical and scientific venues; and has generated books or book chapters for publishers of mental health texts. The remaining authors declare no conflict of interest.