Comprehensive Behavioral (ComB) Treatment of Trichotillomania: A Randomized Clinical Trial

Objective: This study is the first controlled trial of comprehensive behavioral (ComB) treatment of trichotillomania (TTM). ComB provides individualized treatment based on factors triggering and maintaining hair pulling.

Method: Participants (N = 36) were adults (M = 34.08 years old, SD = 12.26) meeting DSM5 criteria for TTM. A majority were female (80%) and Caucasian (75%), whereas 17% were African American and 19% Hispanic/Latinx. In a parallel-group design, participants were randomly assigned to (a) Immediate ComB (12 sessions) or (b) Minimal Attention Control (MAC), followed by delayed ComB after week 12. Follow-up continued through week 38. Primary outcomes were self-report (Massachusetts General Hospital Hair pulling Scale; MGH-HPS) and interviewer-rated (NIMH-Trichotillomania Impact Scale and Trichotillomania Severity Scale; TIS/TSS) TTM symptom severity, as well as diagnosis (Trichotillomania Diagnostic Interview).

Results: Immediate efficacy of ComB (vs. MAC) was statistically significant (p = .03) for self-reported symptoms, with an effect size d = -.78, but not significant for interviewer-rated symptoms or diagnostic status. Immediate ComB was significantly more likely than MAC (27% vs. 0%) to lead to complete abstinence from hair pulling at week 12. Follow-ups showed good maintenance of effects.

Conclusions: Efficacy of ComB was established for self-reported symptoms. Future research is needed to establish whether the lack of more widespread effects stems from limitations of the model or to a need for more extensive therapist training, as secondary analyses suggested stronger results among therapists with more TTM experience.