Objectives: ：This study aims to confirm the effectiveness of a school-based very-short-term dialectical be-havior therapy-skills training (DBT-ST) program for preventing self-harm among children and adolescents, considering factors such as age, sex, self-harm history, and methods of program implementation. Methods: ：The study was conducted from September 2021 to December 2023, targeting 1,012 elementary and middle school students in the Chungcheong region. Changes in responses to the Depressed Mood Questionnaire(RDQ), the Difficulties in Emotion Regulation Scale-16 (DERS-16), ‘future self-harm possibility’ scores wereanalyzed and compared before and after the program, based on age, sex, self-harm history, and methods of program implementation. Results: ：Overall, participants showed a decrease in the ‘rumination(RDQ) scale’ (t=10.49, p<0.001), ‘reversescored distraction (RDQ)’ (t=10.67, p<0.001) and the total DERS-16 (t=5.56, p<0.001) as well as a decrease in ‘future self-harm possibility’ score (t=4.26, p<0.001). Both elementary and middle school students showed decrease in ’rumination (RDQ)’ and distraction (RDQ), but only middle school students showed a decrease in theDERS-16 and most sub-scales. Regardless of sex, self-harm history, or methods of program implementation, adecrease in ’rumination (RDQ)’, distraction (RDQ) and the total DERS-16 scale and most sub-scales decreased. Conclusions ：Our program appears to be effective as a primary prevention program for preventing self-harm among children and adolescents in a school setting.

Objectives: ：This study aims to confirm the effectiveness of a school-based very-short-term dialectical be-havior therapy-skills training (DBT-ST) program for preventing self-harm among children and adolescents, considering factors such as age, sex, self-harm history, and methods of program implementation. Methods: ：The study was conducted from September 2021 to December 2023, targeting 1,012 elementary and middle school students in the Chungcheong region. Changes in responses to the Depressed Mood Questionnaire(RDQ), the Difficulties in Emotion Regulation Scale-16 (DERS-16), ‘future self-harm possibility’ scores wereanalyzed and compared before and after the program, based on age, sex, self-harm history, and methods of program implementation. Results: ：Overall, participants showed a decrease in the ‘rumination(RDQ) scale’ (t=10.49, p<0.001), ‘reversescored distraction (RDQ)’ (t=10.67, p<0.001) and the total DERS-16 (t=5.56, p<0.001) as well as a decrease in ‘future self-harm possibility’ score (t=4.26, p<0.001). Both elementary and middle school students showed decrease in ’rumination (RDQ)’ and distraction (RDQ), but only middle school students showed a decrease in theDERS-16 and most sub-scales. Regardless of sex, self-harm history, or methods of program implementation, adecrease in ’rumination (RDQ)’, distraction (RDQ) and the total DERS-16 scale and most sub-scales decreased. Conclusions ：Our program appears to be effective as a primary prevention program for preventing self-harm among children and adolescents in a school setting.

Objectives: ：This study aims to confirm the effectiveness of a school-based very-short-term dialectical be-havior therapy-skills training (DBT-ST) program for preventing self-harm among children and adolescents, considering factors such as age, sex, self-harm history, and methods of program implementation. Methods: ：The study was conducted from September 2021 to December 2023, targeting 1,012 elementary and middle school students in the Chungcheong region. Changes in responses to the Depressed Mood Questionnaire(RDQ), the Difficulties in Emotion Regulation Scale-16 (DERS-16), ‘future self-harm possibility’ scores wereanalyzed and compared before and after the program, based on age, sex, self-harm history, and methods of program implementation. Results: ：Overall, participants showed a decrease in the ‘rumination(RDQ) scale’ (t=10.49, p<0.001), ‘reversescored distraction (RDQ)’ (t=10.67, p<0.001) and the total DERS-16 (t=5.56, p<0.001) as well as a decrease in ‘future self-harm possibility’ score (t=4.26, p<0.001). Both elementary and middle school students showed decrease in ’rumination (RDQ)’ and distraction (RDQ), but only middle school students showed a decrease in theDERS-16 and most sub-scales. Regardless of sex, self-harm history, or methods of program implementation, adecrease in ’rumination (RDQ)’, distraction (RDQ) and the total DERS-16 scale and most sub-scales decreased. Conclusions ：Our program appears to be effective as a primary prevention program for preventing self-harm among children and adolescents in a school setting.

Objectives: ：This study aims to confirm the effectiveness of a school-based very-short-term dialectical be-havior therapy-skills training (DBT-ST) program for preventing self-harm among children and adolescents, considering factors such as age, sex, self-harm history, and methods of program implementation. Methods: ：The study was conducted from September 2021 to December 2023, targeting 1,012 elementary and middle school students in the Chungcheong region. Changes in responses to the Depressed Mood Questionnaire(RDQ), the Difficulties in Emotion Regulation Scale-16 (DERS-16), ‘future self-harm possibility’ scores wereanalyzed and compared before and after the program, based on age, sex, self-harm history, and methods of program implementation. Results: ：Overall, participants showed a decrease in the ‘rumination(RDQ) scale’ (t=10.49, p<0.001), ‘reversescored distraction (RDQ)’ (t=10.67, p<0.001) and the total DERS-16 (t=5.56, p<0.001) as well as a decrease in ‘future self-harm possibility’ score (t=4.26, p<0.001). Both elementary and middle school students showed decrease in ’rumination (RDQ)’ and distraction (RDQ), but only middle school students showed a decrease in theDERS-16 and most sub-scales. Regardless of sex, self-harm history, or methods of program implementation, adecrease in ’rumination (RDQ)’, distraction (RDQ) and the total DERS-16 scale and most sub-scales decreased. Conclusions ：Our program appears to be effective as a primary prevention program for preventing self-harm among children and adolescents in a school setting.

Objectives: ：This study aims to confirm the effectiveness of a school-based very-short-term dialectical be-havior therapy-skills training (DBT-ST) program for preventing self-harm among children and adolescents, considering factors such as age, sex, self-harm history, and methods of program implementation. Methods: ：The study was conducted from September 2021 to December 2023, targeting 1,012 elementary and middle school students in the Chungcheong region. Changes in responses to the Depressed Mood Questionnaire(RDQ), the Difficulties in Emotion Regulation Scale-16 (DERS-16), ‘future self-harm possibility’ scores wereanalyzed and compared before and after the program, based on age, sex, self-harm history, and methods of program implementation. Results: ：Overall, participants showed a decrease in the ‘rumination(RDQ) scale’ (t=10.49, p<0.001), ‘reversescored distraction (RDQ)’ (t=10.67, p<0.001) and the total DERS-16 (t=5.56, p<0.001) as well as a decrease in ‘future self-harm possibility’ score (t=4.26, p<0.001). Both elementary and middle school students showed decrease in ’rumination (RDQ)’ and distraction (RDQ), but only middle school students showed a decrease in theDERS-16 and most sub-scales. Regardless of sex, self-harm history, or methods of program implementation, adecrease in ’rumination (RDQ)’, distraction (RDQ) and the total DERS-16 scale and most sub-scales decreased. Conclusions ：Our program appears to be effective as a primary prevention program for preventing self-harm among children and adolescents in a school setting.