Bright Light Therapy Not Superior to Placebo for Inpatient Depression Treatment
Bright light therapy alongside treatment-as-usual for adolescent inpatients with depression did not demonstrate superiority over placebo red light therapy, according to recent double-blind, placebo-controlled randomized parallel-group trial results published in JAMA Psychiatry.
“The significant reduction in depressive symptoms observed in both the bright light therapy and placebo red light groups, and the fact that more than 60% of patients were classified as remitted or responsive underscore the effectiveness of the intensive inpatient treatment setting,” authors noted. “However, an additional effect of bright light therapy was not demonstrated.”
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The study was conducted between March 2018 and November 2020 among inpatients aged 12 to 18 with major depressive disorder (MDD) across 4 university hospitals in Germany. Follow-up was completed in May 2021. Of the 248 eligible participants, 227 were randomized to receive either morning bright light therapy (116 participants) or placebo red light therapy (111 participants), alongside multimodal inpatient treatment as usual, with 151 participants completing the study. The primary outcome measured was the change in Beck Depression Inventory-II (BDI-II) score from baseline to post-treatment in the intention-to-treat sample, with interventions comprising up to 20 sessions over 4 weeks.
In the intention-to-treat analyses involving 224 patients (192 girls and 32 boys; mean age, 15.5 years), the baseline mean BDI-II score was 37.3, showing a significant reduction after 4 weeks (post-assessment) by a mean of -7.5 (95% CI, -9.0 to -6.0; Hedges g = 0.71). Notably, bright light therapy did not significantly affect this change, indicating no significant group × time effect. The study experienced a loss to follow-up of 31% (n = 69) at 16 weeks and 49% (n = 110) at 28 weeks, with 10 serious adverse events reported throughout the trial, deemed unrelated to the light treatment under study.
The evaluation of salivary melatonin samples was hindered by dropouts, and the absence of a control group receiving only treatment as usual complicates isolating the effects of bright light therapy or light-based treatment rituals from inpatient treatment alone. Additionally, the lower representation of participants from non-European regions (5%) compared to the catchment areas (approximately 20%) may limit the generalizability of the study's outcomes.
“To further our understanding and improve treatment outcomes, future research should examine the efficacy of bright light therapy in less intensive treatment contexts and target patients with varying severity of depression and comorbidities,” authors concluded.