Obsessive compulsive symptoms and sleep difficulties: Exploring the unique relationship between insomnia and obsessions

Background: Sleep complaints have been linked with Obsessive Compulsive Disorder (OCD), though there is a dearth of research exploring the association between a range of disturbed sleep indicators and obsessive compulsive symptoms (OCS). Two separate studies were conducted to rigorously investigate this relationship in further detail, considering a number of different sleep indices and also the heterogeneous nature of OCS. Methods: Study 1 (n = 167) examined the relationship between OCS and the gold standard self-report assessments for delayed bedtime, sleep quality, nightmares, and insomnia symptoms. Study 2 (n = 352) replicated the primary findings from Study 1 in an independent sample and with an alternative measure of OCD, which takes into account the different OCS dimensions. Results: Results revealed a significant, independent link between obsessions and insomnia symptoms, but not between insomnia and compulsions. When examining the different OCS dimensions, insomnia was again found to bear a specific relationship to obsessions, above and beyond that with the other dimensions. Although depression is often highly comorbid with both OCD and sleep disturbances, depressive symptoms did not explain the OCS-sleep relationship in either study, suggesting a unique association between obsessions and insomnia. Conclusions: Findings indicate that high levels of intrusive thoughts exhibit a specific association with insomnia symptoms-one that is not observed with other OCS. Future research may help elucidate the mechanisms and causal nature of this relationship.