Effect of Bright Light Therapy on Perinatal Depression: A Systematic Review and Meta-Analysis: Effet de la luminothérapie sur la dépression périnatale: une revue systématique et une méta-analyse.

Objective: This study represents the inaugural attempt to systematically review and analyse the efficacy of bright light therapy on depression among women experiencing major depressive disorder or depressive symptoms during the perinatal period, encompassing its efficacy on depression scores, remission rates, and response rates.

Methods: We searched 10 databases for randomized controlled trials examining bright light therapy's efficacy on perinatal depression up to January 2024. Data extraction was performed independently by 2 investigators. The Cochrane Handbook guidelines appraised the study quality, and the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach assessed evidence certainty.

Results: We incorporated 6 studies, encompassing 151 participants. When contrasted with dim light therapy, bright light therapy did not significantly alter depression scores (standard mean difference = -0.29, 95% confidence interval [CI], -0.62 to 0.04, P = 0.08, I² = 34%) or response rates (risk ratio [RR] = 1.56, 95% CI, 0.98 to 2.49, P = 0.06, I² = 0%) in women experiencing perinatal depression. Conversely, bright light therapy was associated with a substantial increase in remission rates (RR = 2.63, 95% CI, 1.29 to 5.38, P = 0.008, I² = 2%).

Conclusion: Bright light therapy did not show efficacy in treating perinatal depression in terms of depression scores and response rates. However, regarding the remission rate, bright light did show efficacy compared to control conditions. Due to the limited sample size in the included studies, type II err or may occur. To obtain more conclusive evidence, future studies must employ larger sample sizes.