Sleep functioning in adults with trichotillomania (hair-pulling disorder), excoriation (skin-picking) disorder, and a non-affected comparison sample

•Sleep problems were greater in TTM and ExD relative to a non-affected group, after controlling for internalizing symptoms.•Pulling and picking severity were not associated with sleep problems after controlling for internalizing symptoms.•Picking during sleep was associated with increased picking severity, internalizing symptoms, and sleep disturbance.•Findings may enhance assessment and intervention for TTM and ExD.

The present study assessed sleep functioning in Trichotillomania (TTM; Hair-Pulling Disorder) and Excoriation (Skin-Picking) Disorder (ExD), and a non-affected comparison group, and examined the prevalence and correlates of bedtime and sleep-related hair pulling and skin picking. Participants were adult internet survey respondents, who met diagnostic criteria for TTM (N=259), ExD (N=182), or did not meet criteria for these disorders (N=148). Individuals with TTM and ExD endorsed significantly greater sleep disturbance relative to the comparison group, even after controlling for internalizing (anxiety and depression) symptoms. Hair pulling and skin picking severity were not significantly correlated with sleep disturbance after controlling for internalizing symptoms. Pulling and picking during sleep occurred at rates of 13% and 27%, respectively. Picking severity, anxiety and depressive symptoms, and sleep disturbance were significantly increased in those who engaged in picking during sleep relative to those who did not endorse this behavior. No significant differences were found between those endorsing pulling during sleep and those not endorsing this on demographic, clinical, or sleep variables. The present study highlights the potential role of sleep disturbance in TTM and ExD, and the need for further research in this area.