A meta-analysis of bright light therapy commissioned by the American Psychiatric Association found it to be more effective than placebo--usually dim light--for both seasonal affective disorder and for nonseasonal depression, with effect sizes similar to those for conventional antidepressants.
A meta-analysis of bright light therapy commissioned by the American Psychiatric Association found a significant reduction in depression symptom severity associated with bright light treatment. Benefit was found for both seasonal affective disorder and for nonseasonal depression, with effect sizes similar to those for conventional antidepressants.