Altered brain functional network topology in Obsessive-Compulsive Disorder: A comparison of patients with varying severity of depressive symptoms and the impact on psychosocial functioning

Obsessive-compulsive disorder (OCD) is associated with psychosocial impairment, which can be exacerbated by depressive symptoms. In this study, we employed graph theory analysis to investigate the association among neuroimaging, clinical features, and psychosocial functioning in OCD patients, with a specific focus on the differential impact of depressive symptoms. 216 OCD patients were divided into two subgroups based on depressive symptoms. Resting-state functional MRI data were acquired from a subset of 106 OCD patients along with 77 matched healthy controls (HCs). We analyzed the topological characteristics of the entail brain and the cognition-related subnetworks and performed Pearson correlation analyses to further explore the relationship with psychosocial functioning. OCD patients with more severe depressive symptoms exhibited greater impairment across all dimensions of psychosocial functioning. Graph theory analysis revealed more pronounced reductions in network efficiency within the entail brain, the default mode network (DMN), and the cingulo-opercular network (CON) among patients with non or mild depressive symptoms. Lower nodal efficiency and degree centrality of the right superior temporal gyrus (STG) were found in OCD patients and these variables were positively correlated with psychosocial functioning impairment. This study revealed that the presence of depressive symptoms generally exacerbated psychosocial functioning impairments in OCD patients. Abnormalities in the functional integration of the whole brain, the DMN, and the CON in OCD patients may comprise the basis of cognitive deficits, while dysfunction of the right STG may affect the psychosocial functioning through its role in emotion, intention perception, and insight.