SBG, grounded in Satir's Iceberg Theory, aims to enhance self-awareness and communication by exploring participants' deeper emotions and beliefs. Sessions include emotional sharing, communication skills training, and role-play exercises. The program spans 15 weekly sessions (2 hours each): 10 for adolescents and 3 involving both adolescents and their parents. Activities focus on practicing communication stances, reflection, and group discussion to foster personal growth and improved relationships. The inclusion of parents is designed to help teens build supportive, resilient connections.

The Hamilton Anxiety Scale (HAM-A) comprises 14 items. Each item is scored on a scale of 0 (not present) to 4 (severe), with a total score range of 0-56, where <17 indicates mild severity, 18-24 indicates mild to moderate severity, and 25-30 indicates moderate to severe severity.

Clinical Global Impressions-Severity (CGI-S) is a standardized assessment tool used by clinicians to rate illness severity, monitor changes over time, and evaluate medication efficacy. It is rated on a seven-point scale: 1=normal, not at all ill; 2=borderline mentally ill; 3=mildly ill; 4=moderately ill; 5=markedly ill; 6=severely ill; 7=among the most extremely ill patients.

The Clinical Global Impression-Improvement (CGI-I) is a 7-point scale that measures the extent to which the patient's illness has improved or worsened relative to baseline at the start of treatment. It is rated on a scale from 1 to 7: 1 = very much improved since the beginning of treatment; 2 = much improved; 3 = minimally improved; 4 = no change from baseline (the start of treatment); 5 = minimally worse; 6 = much worse; 7 = very much worse since the start of treatment.

It is a self-report 7-item scale to measure the severity of anxiety and has been validated in Chinese adolescent populations. The total scores of the GAD-7 range from 0 to 21, with the higher scores indicating higher severity of anxiety disorders. For the cutoff points of the GAD-7 scores, in general, the scores of 5, 10, and 15 match categorization of none/normal (0-4), mild anxiety (5-9), moderate anxiety (10-14), and severe anxiety (15-21), respectively.

The number of DSM-5 diagnoses is assessed using the Mandarin version of the Schedule for Affective Disorders and Schizophrenia for School-Age Children - Epidemiologic version (K-SADS-E), modified to align with DSM-5 criteria.

It aims to evaluate emotional and behavioral challenges in children and adolescents, covering four problem areas: emotional symptoms, conduct issues, hyperactivity/inattention, and peer relationship difficulties. All items are rated on a three-point scale (0=not true, 1=somewhat true, and 2=certainly true). Five positively worded items from different SDQ difficulty scales are reverse-coded. High scores on the difficulties scales indicate a high degree of difficulty; a high score on the prosocial scale indicates a high degree of prosocial behavior.

The 10-item Positive and Negative Affect Schedule for Children/Parents (PANAS-C/P) is used to assess positive and negative emotional states in youth, based on self-report or parent-report of recent emotional experiences. The measure yields two subscale scores: Positive Affect (range 10-50; higher scores indicate greater positive affect) and Negative Affect (range 10-50; lower scores indicate less negative affect).

The Perceived Stress Scale (PSS) is a self-reported measure used to assess the degree to which individuals appraise situations in their lives as stressful. Each item is rated on a 5-point Likert scale (0 = never to 4 = very often). Total scores range from 0 to 40, with higher scores indicating greater perceived stress. Scores of 0-13 indicate low stress, 14-26 indicate moderate stress, and 27-40 indicate high perceived stress.

The WHOQOL-BREF assesses quality of life across physical, psychological, social, and environmental domains. Each item is rated on a 1-5 scale. Domain scores are transformed to a 0-100 scale, with higher scores indicating better quality of life. Interpretation is based on comparisons across domains, changes over time, and reference to population norms; lower scores (e.g., below the 30th percentile) may indicate areas requiring clinical attention.

The Adult Self-Report is a self-report instrument assessing behavioral, emotional, and social functioning over the past 6 months. Items are rated on a 3-point scale (0 = not true, 1 = somewhat true, 2 = very true). A Total Problems score is calculated by summing all problem items, with higher scores indicating greater overall difficulties.

It includes 10 items that describe daily events related to students' academic pressure. Each item is rated on a 5-point Likert scale ranging from 1 = never to 5 = always. The items are averaged to calculate scale scores; the higher the average score, the higher the level of self-reported academic pressure.

The Stressful Life Events Scale assesses the occurrence of stressful life events. In this study, only eight items related to controllable negative events are included. Each item is rated as 0 = no, 1 = yes, and a Total Score is calculated by summing all items, ranging from 0 to 8, with higher scores indicating a greater number of stressful life events.

The Treatment History Questionnaire assesses the types and amounts of previous medical and psychological treatments received. Items include self-reported hospital admissions, days in hospital, emergency department visits, medications, and outpatient psychosocial treatments. Each item is rated 0 = no, 1 = yes, and a Total Score is calculated by summing all items, with higher scores indicating greater use of treatment resources.

The Emotion Regulation Questionnaire for Children and Adolescents is a 10-item self-report measure assessing emotion regulation strategies, including cognitive reappraisal and emotion suppression. Items are rated on a 5-point Likert scale (1 = strongly disagree to 5 = strongly agree). Subscale scores range from 6-30 for cognitive reappraisal and 4-20 for emotion suppression. Higher scores indicate greater emotion dysregulation.

The DTS-SF is a modification of the DTS and contains the highest-loading item from each subscale, forming a single DT factor. As with the DTS, items are rated on a 5-point Likert scale (1 = strongly agree, 5 = strongly disagree), with lower scores indicating poorer ability to withstand and tolerate distress.

The Dialectical Behavior Therapy Skills Use Scale is a 38-item self-report measure assessing the frequency of DBT skills use over the past month. Participants rate how often they used specific skills when facing stressors on a 4-point scale (0 = never to 3 = regularly). A Total Score (range: 0-114) is calculated by summing item scores, with higher scores indicating more frequent use of DBT skills.

The Mindful Attention Awareness Scale is a 15-item self-report measure assessing mindfulness across cognitive, emotional, physical, interpersonal, and general domains. Items are rated on a 6-point scale (1 = almost always to 6 = almost never), reverse-scored, and averaged to yield a total score. Higher scores indicate greater mindfulness.

It is a 12-item self-report instrument used to measure youths' perceptions of the atmosphere in therapy groups. It contains 12 items rated on a 7-point Likert scale, indicating the extent of agreement, ranging from "not at all" (0) to "extremely" (6).

It is widely used to measure therapeutic alliance in research with adolescent populations. The higher the score, the better the therapeutic alliance. Items are rated on a 4-point Likert scale ranging from 1 (Strongly Disagree) to 4 (Strongly Agree) and summed to create a single Total score with a maximum of 48.

The ADBT-SLES is a 12-item questionnaire assessing adolescents' perceived helpfulness of DBT group skills, rated on a 5-point Likert scale (1 = not helpful at all, 5 = extremely helpful). It also includes four open-ended questions exploring participants' learning experiences in the group.

It consists of eight questions (quality of service, kind of service, whether needs were met, likelihood to recommend to a friend, amount of help received, handling of problems, overall satisfaction, and likelihood to return), each rated on a 4-point Likert scale (1-4). Total scores range from 8 to 32, with higher scores indicating greater satisfaction.

This 4-item, content-specific scale is completed by patients after each session using a 5-point Likert scale (1 = very unsatisfied to 5 = excellent). Total scores range from 4 to 20, with higher scores indicating better session evaluation. It is designed to facilitate collaborative adjustments to therapy, including the therapeutic alliance, session content, and relevance.

It contains 6 questions (i.e., reason for drop-out, date of drop-out, number of sessions attended, person who initiated the stop of treatment) to gather information about drop-outs, which is filled in by adolescents.