[Depression and sleep (author's transl)]

Sleep is affected in depression; insomnia is common, sleep of normal duration and hypersomnia less common. All-night studies have shown changes of the two types of sleep. Deep non-REM sleep is abolished during the course of the illness and sometimes also after remission. Paradoxical sleep, which may be reduced or increased in duration, starts sooner after the onset of sleep. According to Kupfler, ease of production of that sleep is specific to primary depression, unipolar or bipolar. A possible relationship between paradoxical sleep and certain types of depression is suggested by the fact that the tricyclic and MAOI antidepressant drugs and lithium reduce or suppress that sleep. Finally, deprivation of paradoxical sleep by repeated waking during the night has been put forward as a form of treatment. Despite the heterogeneous nature of depression, findings at present which show paradoxical sleep pressure provide a pathophysiological basis for the biological problems posed.