Seasonal affective disorder and season-dependent abnormalities of melatonin suppression by light.
Twelve patients with seasonal affective disorder (SAD) and eleven normal controls were exposed to 2000 lux and 300 lux of artificial full-spectrum light on consecutive nights during the winter. Suppression of melatonin secretion under the two light intensities was measured and the difference between their effects was taken as a measure of light sensitivity. The test was repeated in summer in both groups, when the SAD subjects were well. The SAD but not the normal group showed a significant seasonal variation in sensitivity to light. There was evidence of supersensitivity in the winter but also of subsensitivity to light in the summer.
Thompson
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C
Department of Psychiatry, University of Southamptom, Royal South Hants Hospital, UK.
Stinson
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D
Smith
A
A
D000328:Adult; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008027:Light / Q000009:adverse effects*; D008297:Male; D008550:Melatonin / Q000097:blood / Q000378:metabolism*; D008875:Middle Aged; D019964:Mood Disorders / Q000097:blood / Q000209:etiology / Q000628:therapy*; D010507:Periodicity; D010789:Phototherapy; D016032:Randomized Controlled Trials as Topic; D012621:Seasons; D013493:Suprachiasmatic Nucleus / Q000378:metabolism; D013997:Time Factors
D008550:Melatonin