[Endophenotypes of the biorhythms and the sleep in depression]

Chronobiological markers of depression display a biological desynchronization which participates in the pathogenesis of depression. Mood disorders and clock genes have shown significant associations suggesting a possible pathogenetic link between them, providing a privileged base for exploring biorhythmic endophenotypes. They would be useful indicators of vulnerability mechanisms, giving rise to new therapies and prevention programs. Two ways of research are of interest: the study of the genetic determinants of cholinergic hypersensitivity generating REM sleep pressure in depression, and the analysis of clinical response to sleep deprivation suggesting an exploration of links between genomic function of arousal and mood regulation. To date, the empirical principle of behavioral stimulus control reaches the level of the available eco-instrumental synchronization procedures.