Seasonal affective disorder (SAD)

Seasonal affective disorder is a mood disorder in which symptoms of depression occur mostly in the winter months.

The episodes of depression may be atypical.

Bright light therapy:

• reduces the severity of depressive symptoms more than placebo for seasonal affective disorder
• reduces the severity of depressive symptoms more than placebo for non-seasonal depression. However bright light therapy as an adjunct to standard pharmacotherapy does not differ from placebo for non-seasonal depression

Dawn stimulation:

• reduces symptom severity for seasonal effective disorder

Reference:

1. Golden RN et al. The efficacy of light therapy in the treatment of mood disorders: a review and meta-analysis of the evidence. Am J Psychiatry 2005; 162: 656-62.