Efficacy of a portable BLT device on sleep and depressive symptoms in major depressive disorder: A double-blind...

Major depressive disorder (MDD) is a leading cause of disability worldwide and is often associated with anxiety and sleep disturbances. About one-third of patients do not achieve adequate response to pharmacological treatments, underscoring the need for adjunctive non-pharmacological therapies. Bright light therapy (BLT) has shown efficacy in MDD, but conventional devices require patients to remain stationary, limiting adherence. Portable BLT devices may improve convenience and daily integration. This study assessed the efficacy of a portable BLT device on mood, anxiety, and sleep over 8 weeks.

LUMIDEP was a double-blind, placebo-controlled trial. Adults with MDD were randomized to receive active portable BLT or a visually identical placebo. Final analyses included 18 patients (BLT n = 6; placebo n = 12). Patients underwent 30-min daily sessions for 8 weeks while continuing pharmacological treatments. Depressive symptoms were assessed using the Montgomery-Åsberg Depression Rating Scale (MADRS), anxiety with the Hamilton Anxiety Scale (HAM-A), and sleep with the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS).

Baseline PSQI scores were higher in the BLT group. After 8 weeks, PSQI scores improved within the BLT group, while remaining stable in the placebo group, resulting in no significant between-group difference. No significant differences were observed between groups in HAM-A or MADRS.

Portable BLT appeared to improve sleep quality but did not significantly reduce depressive or anxiety symptoms. Interpretation is limited by group differences, treatment heterogeneity, and small sample size. Larger, stratified trials are warranted to clarify the efficacy of portable BLT in MDD.