Participants in this group will receive the emotional regulation skills training (ERST) intervention.

Participants in this group will not receive the intervention initially and will be placed on a waitlist. They will receive the same emotional regulation skills training (ERST) intervention after the experimental group has completed the program.

This intervention is inspired by and incorporates elements of Dialectical Behavior Therapy (DBT). It consists of eight weekly group sessions, each lasting approximately 1.5 to 2 hours, held on school premises. Each group includes 8 to 10 adolescents. The sessions are facilitated by two psychologists and/or senior psychology students who have been specifically trained to deliver the intervention.

The sessions focus on developing various emotional regulation skills, which participants are encouraged to practice both during and between sessions. Some of the key skills covered include Mindfulness, Wise Mind, and Problem-Solving, among others.

Emotional dysregulation is measured using the "Difficulty in Emotion Regulation Scale" (DERS-E). This self-report questionnaire is administered to participants at baseline (Day 0), at the end of the intervention (Month 2), and three months later for follow-up (Month 3).

Psychological functioning screening is assessed using the "Strengths and Difficulties Questionnaire" (SDQ) (self-report version), which measures emotional and behavioral difficulties. The minimum value for the general difficulty scale is 0, and the maximum value is 40, where higher scores indicate worse psychological functioning.

This questionnaire is administered to participants at baseline (Day 0), at the end of the intervention (Month 2), and three months later for follow-up (Month 3).

Anxiety Symptoms are assessed using the "Generalized Anxiety Disorder 7" (GAD-7), which measures the presence and severity of anxiety symptoms. The minimum value for the scale is 0, and the maximum value is 21, where higher scores indicate worse anxiety symptoms.

This questionnaires is administered to participants at baseline (Day 0), at the end of the intervention (Month 2), and three months later for follow-up (Month 3).

A blinded teacher assessment will be conducted at baseline (Day 0), at the end of the intervention (Month 2) to evaluate symptom levels in both groups, using the "Strengths and Difficulties Questionnaire: Teacher-rated" (SDQ). The minimum value for the general difficulty scale is 0, and the maximum value is 40, where higher scores indicate worse psychological functioning.