Adjunctive Bright Light Therapy in Adolescents With Depression and Eveningness

This randomized, placebo-controlled, assessor-blinded trial aims to evaluate the efficacy of bright light therapy (BLT) as a treatment for adolescents with depression and evening chronotype. Eligible participants will be randomized to receive either BLT or dim red light (placebo) daily for 8 weeks. Depression severity, sleep parameters, and circadian markers will be assessed at baseline, during treatment, post-treatment, and at follow-up visits.

Inclusion criteria

• Chinese, aged 12-19 years old;
• Written informed assent/consent of participation into the study is given by the participant and his/her parent or guardian (for those aged under 18), respectively;
• Having a DSM-5 diagnosis of unipolar non-seasonal depression as confirmed by the Chinese version of the Kiddie-Schedule for Affective Disorders and Schizophrenia (K-SADS) psychiatric interview, DSM-5 Seasonal specifier, AND having a score on Children's Depression Rating Scale (CDRS-R) at least 40;
• Being classified as evening chronotype according to the score on the reduced Horne-Östberg Morning-Eveningness Questionnaire (rMEQ), i.e. <12.

Exclusion criteria

• A current diagnosis of substance abuse or dependence; a current or past history of manic or hypomanic episode, schizophrenia spectrum disorders, organic mental disorders, or intellectual disabilities;
• Having a clinically significant suicidality (presence of suicidal ideation with a plan or an attempt) as assessed by K-SADS;
• Having been enrolled in any other clinical trial investigational products within one month at the entry of the study;
• Initiation of or change in antidepressant medication within past 4 weeks;
• Having been or is currently receiving any structured psychotherapy;
• With hearing or speech deficit;
• Night shift worker;
• Trans-meridian flight across at least two time zones in the past 3 months and during the study;
• Presence of an eye disease, e.g., retinal blindness, severe cataract, glaucoma.