[Sleep disorders and neuroendocrine regulation in depression].

In a series of investigations we explored 24 hour neuroendocrine profiles as well as sleep patterns in a sample of monozygotic and dizygotic normal twins as well as in a group of depressed and schizophrenic patients. Our results indicate that genetic factors influence some sleep variables, mainly the slow wave sleep. They also indicate that a disorder of circadian time-keeping (a phase advance of the biological clock) characterizes some forms of affective illness.