Impaired response inhibition in obsessive compulsive disorder

Objective. - The present study investigates different three inhibitory control functions in patients with obsessive-compulsive disorder (OCD). Selective motor response inhibition was tested in a GO/NO-GO paradigm, the inhibition of a triggered motor response in a STOP paradigm and the ability to inhibit cognitive interference in a motor STROOP paradigm. Methods. - 27 patients who met DSM-IV criteria for CCD and 25 age, handedness and IQ-matched healthy control subjects were tested in the GO/NO-GO, STOP and motor STROOP tasks. Results. - OCD patients performed significantly worse than controls in the selective inhibition of their motor responses (GO/NO-GO) and in the inhibition of cognitive interference (STROOP), and also showed worse performance in suppressing previously triggered motor responses (STOP). Conclusion. - Patients with OCD are impaired in motor and cognitive inhibitory mechanisms. The findings are consistent with psychobiological and neuropsychological models of OCD suggesting impairment of frontostriatal circuitries that mediate functions of inhibitory control. (c) 2006 Elsevier Masson SAS. All rights reserved.