Comparing ultraviolet and non-ultraviolet light therapy for seasonal depression

Bright light therapy with ultraviolet (UV) spectrum significantly reduced depression scores in patients with seasonal affective disorder (SAD).

• Treatment with dim light (500 lux) showed no significant antidepressant effects, as indicated by various depression scales.
• Light therapy using bright, full-spectrum light (2500 lux) that included UV reduced depression scores on the Hamilton Rating Scale for Depression (HAM-D), Beck Depression Inventory (BDI), and atypical depressive symptom score.
• In contrast, bright light therapy without UV exposure only significantly reduced atypical depressive symptoms.
• These findings imply that the presence of UV in light therapy may influence treatment outcomes for different depressive symptoms associated with SAD.

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