Working memory training in adults with trichotillomania: A 5-week, single-blind, randomized controlled study

Abstract

ObjectiveThis randomized controlled study investigated the effect of the Cogmed Working Memory Training (CWMT) program on hair-pulling severity and working memory in trichotillomania (TTM). Methods36 adults with TTM were assigned to CWMT or active control (25 sessions, 5 weeks). Data from intention-to-treat [ITT] (CWMT: N = 21; control: N = 15) and per-protocol (CWMT: N = 16; control: N = 13) samples were analyzed. The primary and secondary outcomes were the totals on the Massachusetts General Hospital Hair-Pulling Scale (MGH-HPS) and the Digit Span (Backward) subtest of the Wechsler Adult Intelligence Scale. Assessments occurred at baseline, at 5 weeks, and 3 months post-training. A mixed-model repeated measures ANOVA was done, with the interaction of group x time as primary effect of investigation. ResultsRegarding hair-pulling severity, the interaction effect of group x time was not significant (p = 0.27). Regarding working memory, there was a significant group × time interaction in favour of CWMT (p = 0.03), with improvement in working memory from baseline to 5 weeks (p < 0.001, LS mean difference −1.98). ConclusionsCWMT is not superior to active control in reducing hair-pulling. Working memory improved significantly over the short term with CWMT. The findings are a novel contribution to work on cognitive training effects on problematic repetitive behaviours.