The investigation of mechanisms underlying addictive behaviors: a case-control study.

: The contradictory nature of behavioral addictions has sustained a nondefinitive debate regarding their construct validity. The current study aims at exploring mechanisms underlying two distinct classes of behaviors-behavioral addictions characterized by core alterations in reward processing systems (ARPS) and behaviors with a main function of maladaptive coping. This case-control study included 99 treatment-seeking individuals with a primary diagnosis of alcohol use disorder (male:  = 68; female:  = 31) and 74 healthy control (HC) subjects (male:  = 38; female:  = 36). The severity of maladaptive behaviors was measured through the Shorter PROMIS Questionnaire (SPQ). Latent mechanisms were assessed by the Disinhibition Domain of the Personality Inventory for DSM-5 (PID-5-DI) and the Acceptance and Action Questionnaire-II (AAQ-II). : The clinical group showed higher severity of behavioral addictions than HC. This difference was not replicated for the other class of maladaptive behaviors, except for compulsive buying. Ordinal regression analysis showed that the clinical group significantly predicted SPQ scores reflecting ARPS, SPQ shopping and starving subscales. This was not replicated for the overall SPQ score capturing maladaptive coping and binge eating behaviors. Controlling for PID-5-DI and AAQ-II scores, which were significantly associated to SPQ subscales, effects of the aforementioned clinical group were not significant. The study highlighted distinct and common mechanisms underlying different classes of maladaptive behaviors. Results supported future neuroscience research for clarifying the role of ARPS in compulsive sex and buying in order to consider them as addictive disorders.