Background: Adolescent emotional distress (anxiety and depressive symptoms) is rising globally. The detection rate of depression risk among Chinese middle and high school students reaches 24.6%, with anxiety risk at 18.1%. These conditions show high comorbidity, high recurrence, and high disability rates, seriously affecting adolescents' academic performance, social relationships, and quality of life. Mindfulness-Based Interventions (MBIs) have shown significant effects in children and adolescent populations; meta-analyses indicate a moderate effect size on adolescent internalizing problems (Hedges' g = 0.47). Group-based adolescent mindfulness interventions are feasible, as the group format improves efficiency, reduces costs, and provides social support. However, existing research still has limitations in cultural adaptation and systematic intervention design. The MIED (Mindfulness Intervention for Emotional Distress) systematic theory was developed by researcher Liu Xinghua based on MBSR/UP. Its core theory is the "Diamond Model" of emotional distress, identifying four core maintenance mechanisms: engagement in life, distress tolerance regulation, emotional behavior regulation, and cognitive flexibility enhancement. Adult studies on MIED have shown significant improvements in emotional distress symptoms, but no specialized research has been conducted in adolescent populations.

Methods: This study is a feasibility exploratory study employing a single-group pre-post design, planning to recruit 24-30 adolescents aged 12-18 years with emotional distress, to undergo an 8-week MIED adolescent mindfulness intervention group. Data will be collected at multiple time points: baseline, after session 4, after session 8, and at 1-month follow-up.

Objectives: The primary objective is to evaluate the feasibility of the MIED-based adolescent mindfulness intervention group (recruitment feasibility, retention feasibility, implementation feasibility, acceptability, and safety). The secondary objective is to preliminarily assess the intervention's effectiveness on outcomes such as anxiety, depression, and stress, estimate effect sizes, and provide methodological preparation for subsequent large-scale randomized controlled trials (RCTs).