Bipolar Depression Benefits From Midday Bright Light Therapy

HealthDay News — Midday bright light therapy may be effective for treating bipolar depression, according to a study published online in The American Journal of Psychiatry.

Dorothy K. Sit, MD, from Northwestern University in Chicago, and colleagues randomly assigned participants (depressed adults with bipolar I or II disorder who were receiving stable dosages of antimanic medication) to treatment with either 7000-lux bright white light or 50-lux dim red placebo light (23 participants in each group). They received daily treatment at midday for 6 weeks, and symptoms were assessed weekly.

The researchers found that the group treated with bright white light experienced a significantly higher remission rate than the placebo light group (68.2% vs 22.2%; adjusted odds ratio, 12.6) during weeks 4 to 6. 

The bright white light group also had significantly lower depression scores at the endpoint visit. There were no mood polarity switches. Sleep quality improved and was similar in both groups.

“The data from this study provide robust evidence that supports the efficacy of midday bright light therapy for bipolar depression,” conclude the authors.

Reference

Sit DK, McGowan J, Wiltrout C, et al. Adjunctive bright light therapy for bipolar depression: a randomized double-blind placebo-controlled trial [published online October 3, 2017]. Am J Psychiatry. doi:10.1176/appi.ajp.2017.16101200