Photoreceptor System for Melatonin Regulation and Phototherapy

Light is the primary stimulus for regulating circadian rhythms, seasonal cycles, and neuroendocrine responses in many species including humans. During the past 20 years, studies have tested the use of light for treating fall and winter depression (Seasonal Affective Disorder or SAD), non-seasonal depression, sleep disorders, menstrual dysfunction, and eating disorders. In addition, investigators are exploring the use of light for reentraining human circadian physiology relative to the challenge of shift work or intercontinental air travel.