This study sought to investigate the effectiveness of group treatment for trichotillomania (TTM) in ordinary clinical settings. Treatment consisted of a combination of habit reversal training (HRT) and acceptance and commitment treatment (ACT). Both short- and long-term effects were explored, as well as individual change trajectories.
The sample consist of fifty-three patients with TTM. Treatment outcomes were evaluated at post-treatment and at one-year follow-up using self-report questionnaires (Massachusetts General Hospital Hair Pulling Scale, MGH-HS), structured clinical interviews (National Institute of Mental Health Trichotillomania Severity Scale, NIMH-TSS), and the Clinical Global Impression scale for TTM (CGI-TTM).
Analyses by mixed models for repeated measurements yielded a statistically significant effect of time (p<.001) for all outcome measures. There were large effect sizes, ranging from 1.76 to 2.33 at post-treatment and from 1.03 to 1.43 at one-year follow-up. Nearly 90% of patients scored below the diagnostic threshold at post-treatment on the CGI-TTM, and slightly more than 60% remained so at one-year follow-up. There were large and statistically significant differences in the change profiles across the patients from post-treatment to one year follow-up.
ACT-enhanced behavior therapy in a group format seems efficient for reducing symptoms of trichotillomania.