[Sleep disorders and psychiatry. Keys for trans-nosological symptomatology, genetic epidemiology and dynamic pathogenesis].

Sleep studies in psychiatry collect various disorders in the category of "dysomnia", and sleep EEG studies today can be routinely performed using appropriate autonomous devices. Three major needs emerge from a broad approach of the topic: a transnosological view on symptomatology--dysomnia gets its meaning from the context, a genetic epidemiology--dysomnia appears as a risk factor for psychiatric disorders and a marker of depressive vulnerability, and as a dynamic pathogeny. A wide consensus arises in the field of polysomnographic studies claiming a clear distinction between two opposite sleep EEG basic disturbances: the non specific increase of wake during the sleep process, seen in anxiety disorders, primary insomnia and several activation situations and related to a sleep-wake instability, and the specific endogenous pattern seen in depression which suggests a super-sleep syndrome. Sleep EEG studies can provide additional information on the biological basis of the disorders, both as diagnostic criteria extension and as therapeutic intervention aid.