Bright Light Therapy Effective for Depressive Disorders, May Improve Treatment Response Time
Bright light therapy (BLT) may be an effective adjunctive treatment for non-seasonal depressive disorders and improve response time for the initial treatment, according to results from a recent systematic review and meta-analysis published in JAMA Psychiatry.
Authors searched the MEDLINE, Embase, and Cochrane databases for randomized clinical trials (RCTs) investigating BLT effects in patients with non-seasonal depression. RCTs comparing BLT and dim red light versus antidepressant monotherapy alone, published between January 1, 2000, and March 25, 2024, were considered for inclusion. Differences between patients treated with and without BLT were examined using the Mantel-Haenszel method, and heterogeneity was assessed using I2 statistics.
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In total, 11 trials with data from 858 patients were included, of which 75.6% were female. Statistically significant better remission and response rates were found in the BLT group (remission: 40.7% vs 23.5%; odds ratio [OR], 2.42; 95% CI, 1.50-3.91; P <.001; I2 = 21%; response: 60.4% vs 38.6%; OR, 2.34; 95% CI, 1.46-3.75; P <.001; I2 = 41%). With BLT, subgroup analysis based on follow-up times also showed better remission (<4 weeks: 27.4% vs 9.2%; OR, 3.59; 95% CI, 1.45-8.88; P = .005; I2 = 0% and >4 weeks: 46.6% vs 29.1%; OR, 2.18; 95% CI, 1.19-4.00; P = .01; I2 = 47%) and response (<4 weeks: 55.6% vs 27.4%; OR, 3.65; 95% CI, 1.81-7.33; P <.001; I2 = 35% and >4 weeks: 63.0% vs 44.9%; OR, 1.79; 95% CI, 1.01-3.17; P = .04; I2 = 32%) rates.
Authors indicated a few limitations of the study. There were some differences in mean follow-up time in the included studies— the available data prohibited researchers from separately analyzing each included depressive disorder, each study defined remission rate and response to treatment using different parameters, and one study had an important discontinuation of participants during follow-up time,
“Conducting trials in a multicentric manner around the globe would help determine whether seasonal differences regarding photoperiod daylight time impact or do not impact the outcomes of BLT treatment for nonseasonal depressive disorders,” authors concluded. “Enrollment of various grades of MDD in trials assessing BLT effects could complement statistical analysis by providing sufficient data to compare subgroups according to MDD severity. Further research is also indicated to explore imaging studies for elucidation of the intricate mechanism of action of light in mood regulation.”
