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.

• Bright light therapy (Device): Exposure to blue-enriched white light for 15-30 minutes a day for 8 weeks
• Dim red light (Device): Exposure to dim red light for 15-30 minutes a day for 8 weeks.

Primary outcomes

• Change of depressive symptoms [Soon after the intervention]: Change in the score of the Children's Depression Rating Scale (CDRS-R), which ranges from 17-113, higher score indicates higher severity of depression.

Secondary outcomes

• Change of other clinical symptoms [Soon after the intervention]: Change in Beck Depression Inventory (BDI) score, which ranges from 0-63, higher score indicates greater depression severity.
• Change of other clinical symptoms [Soon after the intervention]: Change in Pittsburgh Sleep Quality Index (PSQI) score, which ranges from 0-21, higher score indicates poorer sleep quality.
• Change of other clinical symptoms [Soon after the intervention]: Change in Behavior Rating Inventory of Executive Function (BRIEF2) score, which will be transformed into T scores (range = 35 to ≥ 90) for interpretion, higher score indicates higher executive functioning.
• Change of other clinical symptoms [Soon after the intervention]: Change in KIDCSREEN-27 score, which ranges from 30-135, higher score indicates better life quality and social support.

Sex: All, ages: 12 Years to 19 Years

Inclusion Criteria:

1. Chinese, aged 12-19 years old;
2. 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;
3. 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;
4. Being classified as evening chronotype according to the score on the reduced Horne-Östberg Morning-Eveningness Questionnaire (rMEQ), i.e. <12.

Exclusion Criteria:

1. 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;
2. Having a clinically significant suicidality (presence of suicidal ideation with a plan or an attempt) as assessed by K-SADS;
3. Having been enrolled in any other clinical trial investigational products within one month at the entry of the study;
4. Initiation of or change in antidepressant medication within past 4 weeks;
5. Having been or is currently receiving any structured psychotherapy;
6. With hearing or speech deficit;
7. Night shift worker;
8. Trans-meridian flight across at least two time zones in the past 3 months and during the study;
9. Presence of an eye disease, e.g., retinal blindness, severe cataract, glaucoma.