First, the guardian of the participant will read the informed consent. After the guardian signs the informed consent, the participant will complete the demographic, emotional and cognitive pre-assessment. The participant will then receive a group cognitive behavioral intervention for 40 minutes each day in the following 3 days. The intervention will take place in school classrooms in a format similar to offline school classes. The therapists are one senior undergraduate and one first-year PhD student from the School of Psychological and Cognitive Sciences who have received sufficient training. The intervention based on the theory of children's cognitive behavioral therapy, with a self-compiled manual. The three sessions are aimed at emotional awareness and management, thoughts recognition, and coping. Each session will be accompanied by the presence of the head teachers.

For DA group, the procedures of informed consent, pre assessments, cognitive behavior group intervention, and follow-up assessments will be the same as those for WA. After completing the group intervention, the participants in DA will be required to complete the GNT drawing in accordance with the guidelines at a fixed time each day, under the guidance and supervision of the school teachers, and to complete two short mood tests and the post-painting assessments in the following 3 days. Each drawing session will last for 20-30 minutes.

School-based CBT intervention: a 3-day, 40-minute per day cognitive behavioral intervention. The intervention will take place in a school classroom in a format similar to offline classroom lectures and classroom interactions. The intervention will lead by one undergraduate student from the School of Psychological and Cognitive Sciences and one first-year doctoral student with training in clinical psychology. The content of the intervention was based on the theory of cognitive behavioral therapy for children, with a complete self-developed intervention manual, and three interventions targeting emotional awareness and management, thought recognition, and problem coping, respectively.

Child anxiety and depression symptoms measured by RCADS-25.

The Child PTSD Symptom Scale for DSM-5 (CPSS-5) for adolescents and children (scores from 0 to 4, and total scores vary from 0 to 80). A higher score represents worse PTSD symptoms.

A 30-item Emotion awareness questionnaire measures emotion awareness on a 3-point Likert scale (1 to 3, and total scores vary from 30 to 90). A higher score represents better emotion awareness.