Kuiper, L.B. & Coolen, L.M.
https://doi.org/10.1007/s11930-018-0157-2
Preclinical and Psychophysiology (F Guarraci and L Marson, Section Editors)
Abstract
Purpose of Review
Compulsive sexual behavior (CSB) is widely regarded as a “behavioral addiction,” and is a major threat to quality of life and both physical and mental health. However, CSB has been slow to be recognized clinically as a diagnosable disorder. CSB is co-morbid with affective disorders as well as substance use disorders, and recent neuroimaging studies have demonstrated shared or overlapping neural pathologies disorders, especially in brain regions controlling motivational salience and inhibitory control.
Recent Findings
Clinical neuroimaging studies are reviewed that have identified structural and/or function changes in prefrontal cortex, amygdala, striatum, and thalamus in individuals suffering from CSB. A preclinical model to study the neural underpinnings of CSB in male rats is discussed consisting of a conditioned aversion procedure to examine seeking of sexual behavior despite known negative consequences. Using this preclinical model, a role of the medial prefrontal cortex was identified, including neural plasticity during comorbidity of CSB and psychostimulant abuse.
Summary
This review summarizes recent human behavioral and neuroimaging studies, in addition to preclinical models that can be used to study the underlying neurobiology of CSB.
Keywords – Compulsive sexual behavior, Hypersexuality, Addiction, Prefrontal cortex, Limbic system, Sexual behavior
Because CSB shares characteristics with other compulsive disorders, namely, drug addiction, comparisons of findings in CSB, and drug-addicted subjects, may be valuable to identify common neural pathologies mediating comorbidity of these disorders. Indeed, many studies have shown similar patterns of neural activity and connectivity within limbic structures that are involved in both CSB and chronic drug use [87–89]. For example, in cocaine-addicted patients, overlapping brain regions are activated by both cocaine and sex cues, including the ventral tegmental area, amygdala, nucleus accumbens, orbitofrontal cortex, and insular cortex [90]. In a recent fMRI study by Moeller and colleagues, individuals with cocaine use disorder chose to view cocaine-related images more often than healthy controls, a choice that correlated with neural activity in dorsal anterior cingulate cortex and ventral tegmental area [91],which are areas consistently found to be activated by erotic stimuli [92]. Interestingly, this study found that greater activity in lateral orbitofrontal cortex, which has also been shown to be activated by viewing sexually explicit images [93], correlated with lower choice for viewing cocaine-related images, possibly indicative of activity related to an aversive response [91].
In conclusion, this review summarized the behavioral and neuroimaging studies on human CSB and comorbidity with other disorders, including substance abuse. Together, these studies indicate that CSB is associated with functional alterations in dorsal anterior cingulate and prefrontal cortex, amygdala, striatum, and thalamus, in addition to decreased connectivity between amygdala and prefrontal cortex. Moreover, a preclinical model for CSB in male rats was described, including new evidence of neural alterations in mPFC and OFC that are correlated with loss of inhibitory control of sexual behavior. This preclinical model offers a unique opportunity to test key hypotheses to identify predispositions and underlying causes of CSB and comorbidity with other disorders
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