The authors treated winter depression in 13 patients with typical
seasonal affective disorder by extending the length of winter days with
bright and dim light in the morning and evening in a balanced-order
crossover study. Bright light had a marked antidepressant effect, whereas
the dim light did not. This response could not be attributed to sleep
deprivation. Subsequent pilot studies indicated that bright evening light
alone is probably also effective. Several patients were able to maintain
the antidepressant response throughout the winter months by continuing
daily light treatments.
Abstract Teaser