Dim versus bright red (light-emitting diode) light in the treatment of seasonal affective disorder.
Forty-three subjects with seasonal affective disorder were randomly assigned to receive 2 weeks of treatment with either bright- (mean 4106 lx) or dim-light (mean 96 lx) therapy, using red light-emitting diode light sources, in a head-mounted unit. Defining response as a 50% reduction in the 21-item Hamilton Depression Rating Scale score to a post-treatment score of less than 8, there was no significant difference in response rate between patients receiving bright light (67%) as compared with patients receiving dim light (68%). Possible explanations for the similar response rate to 2 very different illuminances of red light are discussed.
Levitt
A J
AJ
Department of Psychiatry, University of Toronto, Ontario, Canada.
Joffe
R T
RT
King
E
E
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010789:Phototherapy / Q000379:methods*; D016574:Seasonal Affective Disorder / Q000628:therapy*