In 2022 WHO included Compulsive Sexual Behavior Disorder (CSBD) in the 11th edition of the International Classification of Disorders. The majority of people meeting CSBD criteria seek treatment for problematic pornography use (PPU). There is a lack of consensus on how to conceptualize PPU. Therefore, in the series of 3 studies we have examined structural (VBM, DTI) and functional (fMRI) brain similarities and differences between 82 individuals with PPU, 28 with Alcohol Use Disorder (AUD), 22 with Gambling Disorder (GD), Obsessive Compulsive Disorder (OCD) and 76 healthy control (HC) subjects. In the 4th study, we assessed brain activity (fMRI) before and after 5-month pharmacological treatment (randomized clinical trial with paroxetine, naltrexone and placebo) in a group of additional 72 individuals with PPU.

Results uncovered similarities between PPU, AUD and GD in lower prefrontal cortex (PC) volume (VBM) when compared to HC and showed negative relation between anterior cingulate cortex (ACC) volume and severity of symptoms. Results of DTI are not conclusive and suggest that PPU shares similarities both with OCD and AUD. Results of fMRI assessed during the incentive delay task with monetary and erotic trials uncovered increased cue-reactivity (specific for erotic but not monetary cues) in ventral striatum (VS) and orbitofrontal cortex (OFC) among PPU subjects and suggest incentive sensitization in this group. VS sensitization was positively related to clinical symptoms. Results of our randomized clinical trial show that both active arms of treatment (compared to placebo) resulted in decreased VS sensitization and symptoms improvement after the treatment. 

Our results suggest that PPU may share similar structural vulnerabilities (e.g. decreased VBM in PC and ACC) to AUD and GD, and is related to incentive sensitization for erotic cues. Functional alteration in VS and OFC may play a causal role in PPU and can be partially reversed with pharmacological treatment.