Role of comorbid depressive symptoms on the cognitive deficits in obsessive compulsive disorder

Background: Obsessive compulsive disorder (OCD) is a chronic distressing condition that is marked with impairment in daily functioning including social, family, and occupational areas of life. Depression is the most common comorbidity among patients with OCD. The presence of co-occurring depressive symptoms adds to the burden of the OCD. Previous studies with neuropsychological testing reveals a pattern of cognitive deficits among patients with OCD. Few studies have also shown that the cognitive deficits in OCD are mediated by comorbid depressive symptoms.

Objective: The objective of this study was to assess whether the comorbid depressive symptoms have any role on the cognitive deficits in OCD.

Methodology: Forty patients diagnosed with OCD with an elevated rating in Beck Depression Inventory (BDI) and 20 normal controls were chosen for the study. The forty patients were split according to the severity scores of BDI as per one group consisting of patients with only mild depression and other group consisting of patients with moderate and severe depression. Yale-Brown Obsessive Compulsive Scale has been administered to assess the severity and symptoms of the disorder. Digit Vigilance Test and Triads Test have been administered to assess attention; Comprehensive Trial Making Test (CTMT) and Rey Complex Figure Test have been administered to assess attention, executive function, and memory.

Results: OCD patients have significantly performed poor than the normal controls. On further analysis, OCD patients with moderate and severe depressive features have performed poor than the patients with mild depressive features on the tests administered for attention, executive function, and memory. On assessing the role of comorbid depressive features on cognitive deficits, having mild depressive features were not found to be significantly correlated to the cognitive deficits, whereas patients having moderate and severe depressive features were found to be significantly correlated to the cognitive deficits among OCD patients.

Conclusion: The findings suggest that the higher level of depressive symptoms is associated with cognitive deficits in OCD patients. It can be suggested that the comorbid moderate-to-severe depressive symptoms play an important role in the cognitive deficits found among the OCD patients.