Efficacy of bright light therapy improves outcomes of perinatal depression: A systematic review and meta-analysis of randomized controlled trials.

The efficacy of bright light therapy (BLT) in the context of perinatal depression remains underexplored. This meta-analysis aimed to systematically assess the effectiveness of BLT among perinatal depression. A comprehensive literature search was performed across several databases, including the Cochrane Central Register of Controlled Trials, PubMed, Embase, CNKI and the clinical trials registry platform, covering the period from the inception of each database up to January 2024. The Cochrane Collaboration's bias assessment tool was employed to evaluate the quality of the included studies. Review Manager 5.3 Software was utilized to conduct the meta-analysis. Six trials, encompassed a total of 167 participants diagnosed with perinatal depression were incorporated quantitative analysis, all of those have been published in English, with no restriction on publication year, and used BLT and dim light therapy (DLT) as intervention. The relative risk (RR) of BLT compared to DLT for perinatal depression is 1.46 (fixed effects model, p = 0.04, 95 % CI = [1.02, 2.10]), indicating a significant improvement in depression outcomes compared to DLT groups. The heterogeneity test yielded an I2 value of 41 % (p = 0.13), indicated a low degree of heterogeneity. Considering the small sample size, we conducted a sensitivity analysis, found RR increased to 2.33 (fixed effects model, p = 0.001, CI = 1.39-3.92). Cochrane Risk of Bias Tool showed only a single study was deemed high quality. This study indicates a beneficial impact of BLT on perinatal depression, subgroup analysis finds no significant mediation effects of different parameters after sensitivity analyses. It is recommended that future studies with larger samples be conducted to explore the effects of BLT on perinatal depression.