Today, the role of emotion regulation in mental illness and learning and functional abilities of adolescent students has been confirmed and is an important basis for the emergence of emotional and behavioral disorders during adolescence. Therefore, this study aimed to determine the effectiveness of mindfulness-based group therapy on cognitive emotion regulation in female adolescents.

In this study, a pre-test-post-test design with a control group was used along with a two-month follow-up. Among these students, 30 (15 in the experimental group and 15 in the control group) were selected by cluster sampling and randomly assigned to the experimental and control groups. The instrument used in this study was the Cognitive Emotion Regulation Questionnaire by Granfski, Craig and Spenhaun (2001). The students in the experimental group received eight sessions of mind-awareness training and the control group did not receive any intervention.

The results of analysis of covariance and repeated measures showed that mindfulness-based group therapy is effective on cognitive emotion regulation in female adolescents and this effect has been stable in the follow-up test.

The results showed that mindfulness therapy increased positive cognitive-emotional regulation and decreased negative cognitive-emotional regulation; Based on the research findings, counselors and psychologists are recommended to use mindfulness-based group therapy as an effective method to increase positive emotional regulation in female adolescents.