Light therapy for older patients with non-seasonal depression: A systematic review and meta-analysis

Background: Light therapy has become an increasingly common treatment for adults with depression, yet the role of light therapy for non-seasonal depression among older adults remains unclear. Objective: This meta-analysis sought to evaluate the effectiveness of light therapy among older patients with nonseasonal depression. Methods: We searched the Cochrane Central Register of Controlled Trials, PubMed, Embase, Web of Science, CNKI and CBM from the inception of each database to May 2017. Two researchers conducted the literature screening, data extraction, and methodological quality assessment independently. We used the Cochrane Collaboration's bias assessment tool to evaluate the risk of bias for included studies, and Review Manager 5.2.3 Software for the meta-analysis. Results: Six trials with a total of 359 patients were included, and five studies were assessed as being of low risk for bias. We evaluated the effect of light therapy on depression by the reduction of depressive symptoms (SMD = 0.45; 95% CI= [0.14, 0.75]). The subgroup analysis did not find significant moderating effects of depression with intervention intensity, light type, measuring scale or intervention duration. Limitations: Most of the study samples were not representative of the larger population of adults and therefore caution should be used when interpreting the findings. Conclusions: Light therapy has a positive effect on geriatric non-seasonal depression. Studies with larger sample sizes are needed to confirm the curative effect of light therapy in the future.