Co-occurring depression and obsessive-compulsive disorder: A dimensional network approach

Background: Depressive and obsessive-compulsive (OCD) symptoms often co-occur and a number of possible explanations for this co-occurrence have been explored, including shared biological and psychosocial risk factors. Network approaches have offered a novel hypothesis for the link between depression and OCD: functional interrelationships across the symptoms of these conditions. The few network studies in this area have relied largely on item, rather than process-level constructs, and have not examined relationships dimensionally. Methods: Network analytic methods were applied to data from 463 treatment-seeking adults with OCD. Patients completed self-report measures of OCD and depression. Factor analysis was used to derive processes (i.e., nodes) to include in the network. Networks were computed, and centrality, bridge, and stability statistics examined. Results: Networks showed positive relations among specific OCD and depressive symptoms. Obsessions (particularly repugnant thoughts), negative affectivity, and cognitive-somatic changes (e.g., difficulty concentrating) were central to the network. Unique relations were observed between symmetry OCD symptoms and cognitive-somatic changes. No direct link between harm-related OCD symptoms and depression was observed. Conclusions: Our results bring together prior findings, suggesting that both negative affective and psychomotor changes are important to consider in examining the relationship between OCD and depression. Increased consideration of heterogeneity in the content of OCD symptoms is key to improving clinical conceptualizations, particularly when considering the co-occurrence of OCD with other disorders.