Sleep in obsessive-compulsive and related disorders: a selective review and synthesis.

Despite growing interest in the link between sleep disturbance and psychopathology, much remains unknown regarding obsessive-compulsive and related disorders (OCRDs). The present review integrates contemporary research on the relations between sleep and OCRDs, including hoarding disorder, trichotillomania, and excoriation disorder in order to inform future programmatic research. Findings indicate a robust link between sleep disturbance and OCD; however, the impact of sleep on OCD treatment outcome is unclear. Extant work on sleep disturbance in hoarding disorder indicates a relationship independent of comorbidities. In contrast, observed links between trichotillomania, excoriation disorder, and sleep may be due to mood and anxiety symptoms. These findings suggest that sleep disturbance may indicate a more similar pathophysiology between OCD and hoarding relative to trichotillomania and excoriation disorder. However, given limited research in this area, these findings should be interpreted with caution. Additional research is needed to characterize sleep in etiology, maintenance, and treatment of OCRDs.