Hypersexual Behavior Inventory for Men Who Have Sex with Men: Bifactor Validation, IRT Diagnostics, and Clinical Cutoffs

<b>Background:</b> Compulsive Sexual Behavior Disorder is highly prevalent among men who have sex with men (MSM) and is associated with adverse health outcomes, yet validated assessment tools for this population are critically lacking. This research aimed to adapt the Hypersexual Behavior Inventory (HBI) among Portuguese MSM (<i>N</i> = 1116 across four studies). <b>Method and Results:</b> Following translation and adaptation (Study 1a/1b), Exploratory Factor Analysis suggested a two-factor structure of the instrument (Study 2). Moreover, Item Response Theory showed strong item discrimination and convergent/divergent validity. Confirmatory Factor Analysis (Study 3) favored a bifactor structure-one general hypersexuality factor plus two facets (Control/Consequences and Coping). Criterion validity was evident from positive associations with depression, anxiety, and stress. Finally, ROC analyses (Study 4) demonstrated excellent discrimination and established clinical cutoffs. <b>Conclusions</b>: Overall, the HBI emerges as a reliable, culturally attuned tool for early risk identification in MSM and for informing tailored psychosocial interventions in health settings.