Seasonal Affective Disorder and Light Therapy

Seasonal affective disorder (SAD) is a multidimensional disorder, manifested in individual patterns. As applied to SAD, a proliferation of studies of this disorder, of its response to light, and of its psychological and psychophysiological correlates leads to a view of SAD as multidimensional, manifested in individual patterns that have both common elements and also highly divergent aspects. The importance of light as a corrective treatment with results superior to placebo has been established, and standards for the safe and effective practice of light therapy have been propounded. Meanwhile, research continues on strategies for optimizing the effectiveness of light timing, intensity, and spectrum for SAD and related circadian disorders.