Impact of comorbid depressive symptoms on neuropsychological performance in obsessive-compulsive disorder

There is indirect evidence from previous research that several executive di sturbances in obsessive-compulsive disorder (OCD) are mediated by comorbid depressive symptoms. For the present study, the authors investigated whethe r OCD patients with elevated Hamilton Rating Scale for Depression (HRSD; M. Hamilton, 1967) scores would exhibit deficits in tasks sensitive to the me dial and dorsolateral frontal cortex as well as other executive tasks. The 36 OCD patients were split along the median according to their HRSD scores and compared with matched control subjects. Patients with high HRSD scores performed significantly worse than control subjects and patients with low H RSD scores on the Wisconsin Card Sorting Test (J. Loong, 1990), the Trail-M aking Test (TMT, Part B; R. M. Reitan, 1992), and the TMT difference score. Moreover, patients with high HRSD scores exhibited deficits on a (creative ) verbal fluency task. It is suggested that comorbid depressive symptoms ma y have artificially inflated some executive deficit scores in previous stud ies.