PSORALENS IN ASSOCIATION WITH SEASONAL AFFECTIVE-DISORDER

The pathogenesis of seasonal affective disorder (SAD) has been attribu ted to abnormal melatonin metabolism. Perorally administered psoralens increase the daytime levels of melatonin via the competitive inhibiti on of hepatic melatonin metabolism. Some findings among SAD patients a re parallel to those observed after the administration of a psoralen i n healthy subjects. It is hypothesized that there may be a circulating psoralen-like substance which affects SAD patients under a low level of illumination. Exposure to bright light during the daylight period w ould normalize the abnormal effect independently of the season.