During the winter, bright light must be supplied with electric lights. Automatic timers with lights positioned over the head of the bed can help. If the intensity of the lights is sufficient, therapy can be effective even if the patient's eyes are closed or covered by bedding. Hypnotics, especially the short-acting compounds, may aid entrainment to an earlier bedtime and sleep onset time. There is considerable uncertainty, however, about the required duration of therapy and whether or not maintenance therapy is required.
Results are variable.
There has been considerable interest recently in melatonin as a treatment for circadian rhythm disorders because it appears to be an important component of the physiology of the circadian timing system. Peak production of melatonin occurs in the pineal gland during the dark phase and is suppressed during the light phase. Recent studies have demonstrated that exogenous melatonin, administered orally, may be useful in treating DSPS and other circadian sleep disorders. Administration of melatonin during the early evening may enhance the phase-shifting effect of early morning bright light and, in some individuals, directly produces drowsiness and earlier sleep onset. There are no clinical studies of efficacy and long-term safety of melatonin.