Light therapy in non-seasonal depression: An update meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 32622169 · doi:10.1016/j.psychres.2020.113247
What was done
Authors searched PubMed, Web of Science, Chinese National Knowledge Infrastructure, and Chinese Biomedical Database through February 2020 for randomized controlled trials (RCTs) evaluating light therapy in non-seasonal depression. The primary outcome was the pooled post-trial standardized mean difference in depression scores with 95% confidence intervals versus comparative treatments.
What was found
A total of 23 RCTs with 1,120 participants were included. Light therapy was significantly more effective than comparative treatments, demonstrating a mild to moderate reduction in depressive symptoms. Subgroup analyses did not identify factors explaining the significant heterogeneity observed. Exact effect sizes, confidence intervals, and p-values were not reported in the abstract.
Why it matters
This review provides aggregate clinical evidence that the therapeutic application of light therapy extends beyond seasonal affective disorder to non-seasonal depressive disorders.
Limits
The overall quality of evidence was rated as low by the authors. Significant heterogeneity across trials remained unexplained, and the abstract omitted specific quantitative effect estimates, light delivery parameters, control group definitions, and adverse event profiles.
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