Adjunctive bright light treatment with gradual advance in unipolar major depressive disorder with evening chronotype. - GreenMedInfo Summary
Adjunctive bright light treatment with gradual advance in unipolar major depressive disorder with evening chronotype - A randomized controlled trial.
Psychol Med. 2022 06 ;52(8):1448-1457. Epub 2020 Sep 14. PMID: 32924897
Joey Wy Chan
BACKGROUND: Unipolar non-seasonal depressed patients with concomitant evening chronotype were associated with poor clinical outcomes and higher non-remission rate. This study aims to examine the efficacy of adjunctive bright light therapy with gradual timing advance in a randomized, assessor and prescriber-blinded controlled trial.
METHOD: Participants were randomly allocated to receive 5 weeks of either bright white light therapy (BLT) or dim red light (DRL) with the same advancement protocol. Participants were followed up till 5 months after treatment. Primary outcomes included (i) remission rate and (ii) the severity of depression. The analysis was conducted using Kaplan-Meier survival analysis, Cox proportional hazard analysis and linear mixed models.
RESULTS: A total of 93 participants (46.4± 11.7 years old, 80% female) were randomized. The cumulative remission rate for the BLT and the DRL groups was 67.4% and 46.7%, respectively. Time to remission was shorter for the BLT group relative to the DRL group (log-rank test= 0.024). Cox proportional hazard survival analysis showed that patients in the BLT group had a higher probability of achieving remission relative to patients in the DRL group [hazard ratio = 1.9 (95% CI = 1.1- 3.4),= 0.026]. Further sensitivity analysis demonstrated greater improvement in 17-Hamilton Depression Score (group× time interaction,= 0.04) in the BLT group for those who were adherent to light therapy.
CONCLUSIONS: The use of bright light therapy with gradual advance protocol is an effective adjunctive treatment resulting in quicker and a higher rate of remission of depression in patients with non-seasonal unipolar depression and evening-chronotype.