Neuropsychiatric Disease and Treatment (Nov 2018)
Efficacy of light therapy on nonseasonal depression among elderly adults: a systematic review and meta-analysis
Abstract
Chun-Hung Chang,1,2 Chieh-Yu Liu,3 Shaw-Ji Chen,4,5 Hsin-Chi Tsai6,7 1Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan; 2Department of Psychiatry & Brain Disease Research Center, China Medical University Hospital, Taichung, Taiwan; 3Biostatistical Consulting Laboratory, Department of Speech Language Pathology and Audiology, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan; 4Department of Psychiatry, Mackay Memorial Hospital Taitung Branch, Taitung, Taiwan; 5Department of Medicine, Mackay Medical College, New Taipei, Taiwan; 6Department of Psychiatry, Tzu-Chi General Hospital, Hualien City, Taiwan; 7Department of Psychiatry, School of Medicine, Tzu-Chi University, Hualien City, Taiwan Objective: The aim of this study was to examine the effectiveness of light therapy in the treatment of geriatric depression. Methods: A systematic review and meta-analysis were carried out. Data sources for the literature search were PubMed, Cochrane Collaboration’s Central Register of Controlled Clinical Trials, Cochrane Systematic Reviews, and ClinicalTrials.gov. Controlled trials of light therapy on older patients with nonseasonal depression and depression rating scales were eligible. Studies were pooled using a random-effect model for comparisons with light therapy. We used effect size (ES), which expresses changes in depression severity, in each selected meta-analysis to calculate the standardized mean difference on the basis of Hedges’ adjusted g; positive values indicated that the depression severity improved after light therapy. All results were presented with 95% CIs. Statistical heterogeneity was explored through visual inspection of funnel plots and the I2 statistic. Moderators of effects were explored using meta-regression. Results: We identified eight trials involving 395 participants that met the inclusion criteria. Light therapy was significantly more effective than comparative treatments, including placebo or dim light, with an ES of 0.422 (95% CI: 0.174–0.709, P=0.001). In addition, six of the eight trials used bright (white) light, resulting in significantly reduced severity of geriatric depression (N=273, ES: 0.460, 95% CI: 0.085–0.836, P=0.016). Furthermore, pale blue light therapy reduced the severity of geriatric depression (N=89, ES: 0.464, 95% CI: 0.046–0.882, P=0.030). Conclusion: Our results highlighted the significant efficacy of light therapy in the treatment of geriatric depression. Additional well-designed, controlled studies are necessary to adopt standard parameters, adequate group sizes, and randomized assignment to evaluate more thoroughly the efficacy of light therapy for treating geriatric depression. Keywords: depression, elderly adults, light therapy
