February 22, 2013

The purpose of the study was to determine if bright light therapy improved suprachiasmatic nucleus functioning through decreased depression scores, better sleep efficiency, and decreased urinary cortisol excretion in elderly patients with non-seasonal major depressive disorder. A double blind study of 89 elderly patients was conducted in which 42 received bright light therapy and 47 were part of the placebo group over a course of 3 three weeks. Data was collected before treatment began (T0), after the three weeks of therapy (T1), and three weeks after therapy ceased (T2). The results showed that depression scores and urinary cortisol levels improved in the bright light therapy group significantly more than the placebo group at T1 and T2 (p<.05). Sleep efficiency was significantly increased in from T0 to T1 in the treatment group compared to the placebo (P=.01). At T2 there was no longer a significant difference in sleep efficiency between groups (P=.61). Bright light therapy is a viable alternative to patients with major depressive disorder who do not tolerate antidepressant treatment.