Depression accounts for executive function deficits in obsessive-compulsive disorder

Objective: To examine the relative impact of depression on executive functi on deficits in obsessive-compulsive disorder (OCD). Background: Existing da ta suggest that OCD is associated with basal ganglia and orbital frontal dy sfunction, and neurobehavioral abnormalities that are putatively associated with these regions have been demonstrated in OCD. Nonetheless, few studies have accounted for the effects of depression, which is a common concurrent symptom among those with OCD. Method: A broad battery of neuropsychologica l tests, including measures of executive function and sensory-motor functio n, was administered to 20 adults with OCD and 31 control subjects. To asses s depressive severity, participants were administered the depression scale from the Minnesota Multiphasic Personality Inventory. Results: Data were an alyzed using a regression model in two steps. In step one, patient group wa s entered, and patients with OCD demonstrated a pattern of executive functi on and sensory-motor deficits, similar to those shown in previous research. In step two, self-reported depressive symptom severity was entered as a pr edictor. As a consequence, depression accounted for some executive function deficits, whereas presence of OCD only predicted performance on measures o f sensory-motor function. Conclusions: These data suggest that abnormalitie s involving executive function in OCD are related to co-morbid depressive s everity. However, sensory-motor deficits seem to be more consistent with ba sal ganglia/orbital frontal dysfunction in OCD.