[Pathophysiological bases of obsessive-compulsive disorder and therapeutic implications]

Obsessive-compulsive disorder (OCD), relatively common anxiety disorder (2-3% of the general population), is characterized by persistent, intrusive and unpleasant thoughts, impulses or images and recurrent, time-consuming behaviours that are performed in a ritualistic fashion according to rigid rules and aimed at reducing anxiety and distress caused by obsessions. Significant progress in neuroscience over the last two decades has contributed to improve our knowledge about structure-function relations. Experimental neurophysiology in laboratory animals in parallel with advances in functional neuroimagery in humans, have provided precious information on the pathophysiological bases of OCD. From phenomenological considerations, several processes have been thought as disrupted in OCD, including monitoring of error detection, and emotional and motivational functions. Therefore, it has been postulated that the frontal-subcortical circuits originating in the orbito-frontal and the anterior cingulate cortices respectively, play a major role in the production of obsessive-compulsive symptoms because of their participation in the mediation of all these processes cited above. Such a pathophysiological approach of OCD is of special importance in the development of new strategies for treating OCD such as deep brain stimulation for instance, an innovative non-lesion neurosurgical procedure, which has recently been introduced in the management of severe, chronic forms of OCD resistant to conventional treatments.