Shahroud University of Medical siences Shahroud Journal of Medical Sciences 2423-6594 12 4 2026 08 09 The Effectiveness of Group Counseling Based on Metacognitive Therapy on Reducing Aggression and Improving Psychological Well-Being of Adolescent Girls Who are Children of Divorce 38 43 eng Akbar Ebrahimi Orang Assistant Professor, Department of Psychology and Counseling, Farhangian University, Tehran, Iran. ebrahimiorang@cfu.ac.ir Sana Azimzadeh Master's student, Department of Psychology, Ahar Branch, Islamic Azad University, Ahar, Iran. . Azimzadeh_Saa1n@yahoo.com 2025 06 24 2026 01 19 Background: It seems that divorce is not just an event in the lives of parents and children, but rather a transformation that causes humans to enter a new realm of life, a realm that can have irreparable consequences for children, and its effects can even be observed and examined in later stages of life. The purpose of this study was to determine the effectiveness of group counseling based on metacognitive therapy in reducing aggression and improving the psychological well-being of divorced teenage girls. Methods: This study was a quasi-experimental study with a pre-test-post-test design with a control group. The statistical population included all divorced female high school students in the border city of Parsabad, Moghan, who were selected from high school schools in the academic year 2023-2024 through a convenience sampling method. In the next stage, 40 students with high scores on the aggression questionnaire and low scores on the psychological well-being questionnaire were selected and randomly assigned to the experimental and control groups. The experimental group was trained in metacognitive therapy based on the Wells method for 16 sessions. The research tools included the Bass and Perry aggression questionnaire and the Riff psychological well-being questionnaire. To analyze the data and test the hypotheses, multivariate inferential statistics and analysis of covariance were used, and the data were analyzed using SPSS version 22 software. Results: The results showed that group counseling based on metacognitive therapy had a significant effect on reducing aggression (F=87.51) and improving psychological well-being (F=61.27) of adolescents. According to the findings, the effect coefficient of metacognitive therapy training was 48.3 and 43.2 percent on aggression and psychological well-being of adolescent girls who were children of divorce in the border city of Parsabad, respectively (P-value<0.05). Conclusions: Therefore, it is emphasized that the use of educational and therapeutic centers based on the results of this research in the field of controlling aggression and improving the psychological well-being of students using the metacognitive therapy method.