The role of eveningness in obsessive-compulsive symptoms: Cross-sectional and prospective approaches

Background: Eveningness may be defined as the tendency to be most active and alert during the evening. Previous research has linked eveningness with maladaptive psychological outcomes, and recent evidence has highlighted circadian dysregulation as a novel factor in psychopathology, including obsessive-compulsive disorder (OCD). However, limited research has examined the unique relationship between eveningness and OC symptoms. Two studies were conducted to thoroughly examine the links between eveningness and OC symptoms, while also considering the role of depression symptoms and sleep-related factors. Methods: Using a cross-sectional approach, Study 1 examined the association between eveningness and OC symptoms when controlling for depression symptoms. Study 2 then employed a prospective approach to examine the extent to which the relationship between eveningness and change in OC symptoms over 4 months is mediated by change in sleep disturbance and total sleep time when controlling for depression symptoms. Results: Results indicated that depression better accounts for the cross-sectional association between eveningness and OC symptoms. However, eveningness was found to be a more robust prospective predictor of change in OC symptoms in Study 2. Furthermore, sleep disturbance, but not total sleep time, partially mediated the relationship between eveningness and OC symptoms. Limitations: Single-method self-report approach, unselected sample, and lack of experimental manipulation. Conclusions:These findings suggest that eveningness may contribute to the development of OC symptoms over time, in part due to its effect on sleep disturbance. Future research examining the role of circadian dysregulation in OCD may uncover novel physiological mechanisms.