Objective: Bright light therapy (BLT) has recently come into increasing focus in the treatment of adolescent depression, whereby light glasses today appear to be more feasible than light therapy boxes. This study investigated the feasibility and efficacy of 4 weeks of BLT with light glasses. It also analyzed whether a treatment duration of 4 weeks of BLT yields larger effects than the 2 weeks of BLT investigated in previous studies.
Methods: This first open-label, single-arm, prospective clinical trial pursued a naturalistic approach: 39 inpatients aged 12-18 years with moderate or severe depression received 4 weeks of morning BLT with light glasses in addition to usual treatment. Depressive symptoms, sleep problems, circadian phase, and the clinical global impression were assessed at several timepoints. In a second analysis, the data of the present study were compared to those from a previous pilot trial.
Results: Depressive symptoms, sleep problems, and the global clinical impression improved significantly after BLT with light glasses, whereas the circadian phase did not change over time. Light glasses showed similarly positive effects on sleep parameters and depressive symptoms as light boxes. Contrary to expectation, prolonging BLT to 4 weeks did not yield larger effects on depressive symptoms and sleep complaints compared to 2 weeks of intervention.
Conclusions: Light glasses seem to be a feasible and highly acceptable method for the treatment of adolescent depression. Further randomized controlled trials are needed to obtain sufficient evidence regarding the efficacy of BLT as an add-on intervention to psychological and pharmacological approaches for adolescent depression.
Keywords: adolescents; bright light therapy; depression; light glasses; sleep.