Predicting response to and relapse after treatment of trichotillomania with the Comprehensive Behavioral model (ComB)

Prior studies of behavior therapy for trichotillomania (TTM) have shown that response is variable, and relapse after treatment discontinuation is common. Little information is available concerning prognostic factors capable of predicting individual differences in response or maintenance of improvement. The present study is a secondary analysis of a randomized controlled trial (N = 36) of the Comprehensive Behavioral (ComB) model of treatment for TTM (Carlson et al., 2021). We investigated age, disorder history, pre-treatment symptom severity, longest prior period of abstinence from pulling, and Emotion and Intention hair pulling styles as predictors of initial response. We studied age, disorder history, pre-treatment symptom severity, longest prior period of abstinence from pulling, and post-treatment symptom severity or hair-pulling abstinence as predictors of relapse following treatment. Older age significantly predicted lower TTM severity following treatment. Lower pre-treatment severity significantly predicted lower severity of TTM at the 3-month follow-up.