T. Partonen, EFFECTS OF MORNING LIGHT TREATMENT ON SUBJECTIVE SLEEPINESS AND MOOD IN WINTER DEPRESSION, Journal of affective disorders, 30(2), 1994, pp. 99-108
The effects of morning light treatment on mood, subjective sleepiness
and body temperature were investigated with 13 outpatients with winter
depression and 13 healthy controls. Bright light for 1 h daily for 2
weeks resulted in a significant reduction in depression ratings and ev
ening subjective sleepiness in the patients compared with the healthy
controls. Even a short 15-min exposure to light daily produced these c
hanges.