The Efficacy and Feasibility of Bright Light Therapy in Adolescents With Depressive Disorder

Major Depressive Disorder (MDD) is a chronic disease characterized by a high prevalence, low cure rate, and significant disability. Globally, depression is recognized as the leading cause of illness and disability among children and adolescents aged 10 to 19 years. Bright light therapy has been established as an effective treatment for seasonal affective disorder and has demonstrated considerable efficacy in adult patients with major depressive disorder. However, its application in adolescent patients with major depressive disorder remains largely unexplored. The aim of this clinical trial is to evaluate the efficacy and feasibility of bright light therapy in adolescents with major depressive disorder and to explore the potential neural mechanisms by which bright light therapy enhances emotional and cognitive function in this population. This is a multicenter, randomized, controlled, double-blind study. It will involve adolescents aged 13 to 17 who are either untreated or have been stable on medication for at least one week. Adolescents with major depressive disorder will be randomly assigned to one of three groups: a high-intensity bright light intervention group, a low-intensity bright light intervention group, and a control group receiving dark red light. Each group will undergo four weeks of light exposure, six days per week, for 40 minutes daily between 7:00 and 9:30 AM. During the light exposure period, follow-up assessments will be conducted every weekend, and participants will be followed for two weeks after the completion of light exposure.

Additionally, the study will include healthy adolescent controls and collect functional Near-Infrared Spectroscopy (fNIRS) data from both the adolescent participants with major depressive disorder and the healthy controls at baseline. The fNIRS data will also be collected from the adolescent participants with major depressive disorder at the end of the intervention, in order to investigate the potential neural mechanisms by which light therapy alleviates depressive symptoms in adolescents.


Eligibility Criteria:
1. Adolescents with Major Depressive Disorder

   Inclusion Criteria:all of the following conditions were met for inclusion:
   * Meet the diagnostic criteria for depressive episodes in the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) (either first or recurrent), and be clearly diagnosed by two physicians using MINI-kid 2.0;

     * Age 13 to 17 years, right-handed, and gender-neutral; ③Not currently on medication; or have been stabilized on the original medication regimen for at least 1 week; ④ Hamilton Depression Scale (HAMD-17) score ≥14 at baseline; ⑤ Years of education ≥ 5 years and can cooperate in completing the scale assessment;

       * Subjects volunteered to participate in the study, and both subjects and guardians signed an informed consent form.

   Exclusion Criteria: excluded if any of the following conditions are met:
   * A history of previous or current episodes of other psychiatric disorders, such as (schizophrenia, autism spectrum disorders, and schizoaffective disorders, etc.);

     * Previous history of drug or substance abuse or dependence;

       * Total score of ≥ 8 on the Young's Mania Scale as assessed by the investigator for the subject;

         ④ Have received, or are currently receiving, or have planned to receive in the last month, other systemic interventions other than medication in the 6 months prior to enrollment, e.g., systemic psychotherapy (1 to 2 times per month for more than 6 months), physical therapy other than phototherapy, or exercise therapy;

         ⑤ Those who are medically unstable, or unable to cooperate in completing the study; those who are currently at serious risk of suicide as assessed by the investigator (HAMD-17 entry 3 score ≥ 3);
         * Comorbid serious physical illnesses such as severe liver function abnormalities, hyper/hypothyroidism and abnormal thyroid function, encephalitis, head trauma or coma, epilepsy, loss of consciousness, diabetes mellitus, renal failure, etc.; or those whose clinical laboratory findings at the time of enrollment are, in the opinion of the investigator, significantly out of the reference range and of clinical significance; ⑦ Comorbid visual pathway diseases (retinal detachment, optic nerve atrophy, macular degeneration, etc.), systemic diseases that have an impact on the retina, high myopia (myopia of 600 degrees and above); or those who are using photosensitizers, drugs with potential photosensitizing effects (e.g., chlorpromazine, tricyclic antidepressant, chrysothema, etc.); ⑧ According to the opinion of the research group, those who are not suitable for other conditions of this study.
2. Adolescent Health Controls

   Criteria for inclusion: All of the following conditions were met for inclusion:
   * Age 13-17 years old, right-handed, gender is not limited;

     * Years of education ≥ 5 years, can cooperate with the completion of the scale assessment; ③Subjects volunteered to participate in the study, and both subjects and guardians signed an informed consent form.

   Exclusion Criteria: excluded if any of the following conditions are met:

   ①Previous or current suffering from any mental illness (e.g., schizophrenia, loneliness spectrum disorders, anxiety disorders and schizoaffective disorders, etc.), or a history of drug or substance abuse or dependence;

   ② First-degree relatives with a family history of mental illness;

   ③Comorbid serious physical illnesses such as severe liver function abnormalities, hyper/hypothyroidism and thyroid function abnormalities, encephalitis, head trauma or coma, epilepsy, loss of consciousness, diabetes mellitus, renal failure, etc.; or those whose clinical laboratory findings at the time of enrollment were considered by the investigator to be significantly out of the reference range and of clinical significance;

   ④ Those with other conditions that, according to the opinion of the study group, are not suitable for this study.