Evidence for a deficit in volitional action generation in patients with obsessive-compulsive disorder.

Obsessive-compulsive disorder (OCD) patients show deficits in tasks of executive functioning like the antisaccade (AS) task. These deficits suggest problems in response inhibition or volitional saccade generation. Thirty patients (15 nonmedicated) and 30 healthy subjects performed antisaccades and simple volitional saccades (SVS), that is, centrally cued saccades. In SVS, two aspects of volitional saccade generation were disentangled: response selection and initiation. Latencies of OCD patients were increased in volitional saccades independent of response selection demands. AS performance did not differ. Across groups, latencies in AS were faster than in SVS. Medicated patients did not differ from nonmedicated patients. In sum, response initiation is deficient in OCD patients, which may reflect a general problem in volitional action generation. This deficit did not affect antisaccade performance, possibly due to a lower volitional demand in that task.