Efficacy and Safety of Transcranial Alternating Current Stimulation (tACS) Combined With Stable Medication in Adolescents With Depression

The total number of participants successfully enrolled in this study will be recorded to assess recruitment feasibility. The goal is to recruit 30 participants (15 in each of the two groups) over a 2-year period.

This outcome measure will assess participants' adherence to the 20 sessions of transcranial alternating current stimulation. Adherence is defined as completing all 20 sessions. Adherence is calculated by dividing the number of participants who met this criterion by the total number of participants.

This outcome measure will assess the proportion of participants still enrolled in the study at the 16-week follow-up assessment. Retention rate is calculated as the number of participants who completed the 16-Week assessment divided by the number of participants enrolled at baseline.

Preliminary clinical efficacy will be assessed by change in the Children's Depression Rating Scale-Revised (CDRS-R) total score from baseline. CDRS-R is a clinician-rated scale used to assess the severity of depressive symptoms in children and adolescents. It consists of 17 items, and the total score ranges from 17 to 113. Higher scores indicate more severe depressive symptoms. Changes in CDRS-R total score from baseline will be assessed at the end of treatment and at follow-up visits. Response rate of depressive symptoms will be defined as a ≥50% reduction in CDRS-R total score from baseline, and remission rate of depressive symptoms will be defined as a CDRS-R total score ≤28.

Adverse events, abbreviated as AEs, and serious adverse events, abbreviated as SAEs, will be assessed to evaluate the safety and tolerability of the intervention. An AE is defined as any unfavorable medical occurrence in a participant during the study period, regardless of whether it is considered related to the intervention. An SAE is defined as any adverse event that results in death, is life-threatening, requires hospitalization or prolongation of hospitalization, results in persistent or significant disability/incapacity, or is otherwise considered medically significant. The number and proportion of participants experiencing at least one AE or SAE will be recorded throughout the study period. The severity, outcome, and relationship to the intervention will also be documented.

The Beck Depression Inventory-II, abbreviated as BDI-II, is a 21-item self-report scale used to measure the severity of depressive symptoms. Each item is scored from 0 to 3, and the total score ranges from 0 to 63. Higher scores indicate more severe depressive symptoms. Changes in BDI-II total score from baseline will be assessed at the end of treatment and at follow-up visits.

The Hamilton Anxiety Rating Scale, abbreviated as HAMA, is a clinician-rated scale used to assess the severity of anxiety symptoms. It consists of 14 items covering both psychic anxiety and somatic anxiety symptoms. Each item is scored from 0 to 4, and the total score ranges from 0 to 56. Higher scores indicate more severe anxiety symptoms. Changes in HAMA total score from baseline will be assessed at the end of treatment and at follow-up visits.

The Screen for Child Anxiety Related Emotional Disorders, abbreviated as SCARED, is a self-report scale used to assess anxiety symptoms in children and adolescents. The total score ranges from 0 to 82, with higher scores indicating more severe anxiety symptoms. The change in SCARED total score from baseline will be calculated at each post-baseline assessment time point.

The Columbia-Suicide Severity Rating Scale, abbreviated as C-SSRS, is a clinician-administered scale used to assess suicidal ideation and suicidal behavior. The C-SSRS Suicidal Ideation Severity Score ranges from 0 to 5, where 0 indicates no suicidal ideation and higher scores indicate more severe suicidal ideation. The change in C-SSRS Suicidal Ideation Severity Score from baseline will be calculated at each post-baseline assessment time point.

The Pittsburgh Sleep Quality Index, abbreviated as PSQI, is a self-report questionnaire used to assess sleep quality and sleep disturbances over the past month. The 19 self-rated items are used to generate seven component scores, including subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Each component score ranges from 0 to 3, and the global PSQI score ranges from 0 to 21. Higher scores indicate poorer sleep quality. Changes in the global PSQI score from baseline will be assessed at the end of treatment and at follow-up visits.

The Pediatric Quality of Life Inventory Version 4.0 Generic Core Scales, abbreviated as PedsQL 4.0, is a standardized questionnaire used to assess health-related quality of life in children and adolescents. It consists of 23 items covering four domains: physical functioning, emotional functioning, social functioning, and school functioning. Raw item scores are reverse-scored and linearly transformed to a 0 to 100 scale, with 0=100, 1=75, 2=50, 3=25, and 4=0. The total scale score is calculated as the mean of all answered items, with higher scores indicating better health-related quality of life. Changes in PedsQL 4.0 total score from baseline will be assessed at the end of treatment and at follow-up visits.

The Clinical Global Impression-Severity scale, abbreviated as CGI-S, is a clinician-rated scale used to assess the overall severity of illness at the time of evaluation. It is rated on a 7-point scale, ranging from 1 = normal, not at all ill to 7 = among the most extremely ill patients. Higher scores indicate greater illness severity. Changes in CGI-S score from baseline will be assessed at the end of treatment and at follow-up visits.

The Clinical Global Impression-Improvement scale, abbreviated as CGI-I, is a clinician-rated scale used to assess the overall change in a participant's clinical condition compared with baseline. It is rated on a 7-point scale, ranging from 1 = very much improved to 7 = very much worse. Lower scores indicate greater clinical improvement. CGI-I scores will be assessed at the end of treatment and at follow-up visits.

The Ruminative Responses Scale, abbreviated as RRS, is a self-report scale used to assess the tendency to engage in ruminative thinking in response to depressed mood. The full version consists of 22 items, and each item is rated on a 4-point scale, ranging from 1 to 4. The total score ranges from 22 to 88. Higher scores indicate greater levels of rumination. Changes in RRS total score from baseline will be assessed at the end of treatment and at follow-up visits.