RESUMEN
BACKGROUND AND OBJECTIVES: Reasons for compulsive hair pulling are heterogeneous and not fully understood. Given that many people who experience compulsive hair pulling do not respond to treatment, identifying subgroups can inform potential mechanisms and treatment design. METHODS: We sought to identify empirical subgroups among participants in an online treatment program for trichotillomania (N = 1728). A latent class analysis was used to identify patterns of emotions associated with compulsive hair-pulling episodes. RESULTS: Six classes of participants were found which reflected three predominant themes. One theme reflected expected patterns, where emotional changes were seen following pulling. Two other themes were more surprising, where one reflected high overall emotional activation that did not show consistent change in response to pulling, and another showed low emotional activation overall. These results suggest that there are multiple types of hair-pulling and a sizeable group of people may benefit from treatment adjustments. LIMITATIONS: Participants did not receive semi-structured diagnostic assessment. A majority of participants were Caucasian, and future research would benefit from increased participant diversity. Emotions associated with compulsive hair-pulling were measured across an entire treatment program, but the relationship between specific intervention components and change in specific emotions was not systematically collected. CONCLUSIONS: While previous research has addressed overall phenomenology and comorbidity, the present study is the first to identify empirical subgroups of people who experience compulsive hair-pulling at the level of individual pulling episodes. Identified participant classes had distinguishing features that can aid in personalizing treatment to individual symptom presentations.