[Clinical aspects of obsessive-compulsive disorder]

Obsessive-compulsive disorder is a frequent and chronic disorder accompanied by a marked distress and dysfunction. It is characterised by intrusive thoughts or images (obsessions) which increase anxiety, and by repetitive and ritualistic actions (compulsions) which decrease anxiety. Obsessive-compulsive disorder is frequently complicated by major depressive disorder or other psychiatrics disorders. Unfortunately, it is frequently underdiagnosed and undertreated despite the efficacity of treatments by selective serotonine reuptake inhibitors associated with behavioural and cognitive therapy. Diagnosis of this disorder is easy but needs a good knowledge of symptoms because of the clinical heterogeneity.