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

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.

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).

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.

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.