The treatment of sleep disorders in depressives depends basically on the nature of the underlying affective disorder (endogenous, organic, psychogenic or constitutional depression). Therapeutic approaches may be categorized in: 1) psychological, 2) somatic and 3) pharmacological ones. The former include psychotherapies and behavioral treatments which are useful in psychogenic and constitutional depressions with sleep-onset insomnia but may also be supportive in endogenous depressions. The basic therapeutic factor common to all is anxiety reduction. Somatic therapies, such as ECT, total, partial and REM-sleep deprivation, sleep schedule shifts and bright light (BL) are utilized mostly in endogenous depressions. Sleep laboratory findings and different hypotheses concerning the mode of action of these alternative treatment methods are reviewed. Somnopolygraphic, psychometric, and neuroendocrinological data of our comparative trial with BL and partial sleep deprivation in normals and patients are discussed. The similarity of changes after BL, antidepressants and lithium points to a chronobiological factor in the pathogenesis and treatment of affective disorders. Electrosleep is still controversial, hydro-, ergo- and physical therapy are supportive therapies and as such indicated in all depressions. Exercise, fatigue and nutritional factors may influence sleep. Psychopharmacological treatment has to be regarded as the most important therapeutic approach for sleep disorders in depressives. Antidepressants are the drugs of choice for most patients. Based on their effects on sleep-induction, -maintenance, and -architecture and REM measures, one may differentiate at least two subtypes: sedative antidepressants of the amitriptyline type and nonsedative antidepressants of the desipra-mine type. Bedtime infusions of antidepressants may have sleep promoting properties, which was objectivated by an EEG spectral analysis during infusion and subsequently by all night sleep studies. Measures indicative of therapeutic outcome are still controversial. Tranquilizers, hypnotics, neuroleptics and serotonin precursors are utilized if the antidepressants alone do not ameliorate insomnia. However, as evidence of a shared diathesis of origin of depressive and anxiety disorders is building up, benzodiazepines are increasingly prescribed as monotherapy too. Finally, sleep laboratory data concerning the hypnotic properties of a pharmacological 80 mg dosis of melatonin are demonstrated.