Influence of Comorbid Obsessive-Compulsive Symptoms on Subjective Cognitive Symptoms in Patients with Major Depressive Disorder

Abstract Background : Many clinical studies have shown that patients with major depressive disorder (MDD) or obsessive-compulsive disorder (OCD) display evident cognitive deficits. However, little is known about the impact of these disorders on cognitive symptoms. Methods: This cross-sectional study was conducted with a convenience sampling method to distribute QR codes as an outpatient service. The Patient Health Questionnaire-9 (PHQ-9) assessed for depressive symptoms, and those with a total score ≥ 5 were selected for the analysis. A total of 218 outpatients with MDD were included. The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) was used for OCS. MDD patients with a Y-BOCS score ≥ 6 were classified as MDD with comorbid OCS (MDDOC). The Perceived Deficits Questionnaire-Depression (PDQ-D-5) was used to evaluate subjective cognitive symptoms. A multivariate analysis of covariance and regression models was performed to estimate the effects of OCS on cognitive symptoms. Results: There was no significant difference in cognitive symptoms between MDD alone and MDDOC patients ( p ＞0.05). In the MDDOC subgroup, both the Y-BOCS score and the subdomain (obsession/compulsion) had significant correlations with the PDQ-5 score (r=0.510, 0.504, 0.428, all p ＜0.01, respectively). Further hierarchical regression analyses showed that OCS or the OCS subdomain (compulsion/obsession) contributed to cognitive symptoms (all p ﹤0.05), even when controlling for depression severity ( p ＜0.001; p =0.032; p =0.012, respectively). Moreover,mediation anallysis indicated the ralation between PHQ-9 and subjective cognitive sympton was mediated by OCS. Conclusions: Our findings suggest there is no significant difference in cognitive symptoms between the MDD alone and the MDDOC groups. However, OCS or OCS subdomain may contribute to subjective cognitive symptoms in MDDOC patients. Notably, when controlling for the severity of depression, comorbid OCS aggravated cognition impairment in the MDDOC group.