Predictors of treatment response and relapse for comprehensive behavioral treatment of trichotillomania

Previous research on treatment of trichotillomania (TTM) has shown need for improvement in treatment response and relapse, variance in which may be due to the wide variation of hair-pulling triggers and behaviors in those with TTM. The comprehensive behavioral (ComB) model of treatment, designed to identify and address each individual's hair-pulling modalities, may address these concerns but has not been well-studied. The present study is a secondary analysis of a randomized controlled trial of ComB for TTM (Carlson et al., 2021) using immediate intervention and waitlist conditions, with three-month follow-up. We investigated age, disorder history, pulling style, and baseline severity as predictors of treatment response and age, disorder history, and post-treatment hair-pulling abstinence as predictors of relapse following treatment using stepwise linear regression. Older age significantly predicted lower TTM severity following treatment, the opposite direction as predicted. Lower pre-treatment severity significantly predicted lower severity of TTM at the three-month follow-up. Future research should investigate age as a possible predictor of treatment response and continue to investigate post-treatment hair-pulling abstinence and pre-treatment severity as predictors of maintenance of treatment response.