Year: 2001 Source: Journal of Affective Disorders, v.63, no.1-3, (March 2001), p.123-132 SIEC No: 20011320

The clinical characteristics of 3 seasonal groups & their response to light therapy were compared. 558 patients were assessed. A subset of 192 patients were treatment with an open, 2-week trial of light therapy. The rates of some melancholic symptoms, anxiety, panic, suicidal ideation, & family history of mood disorder were lowest in the subsyndromal seasonal affective disorder group. The clinical response rates to light therapy were highest in subsyndromal group. Results are consistent with a dual vulnerability hypothesis that considers these groups to result from the interaction of separate factors for seasonality & depression. (67 refs.)