خلاصة:
Objective: This study tended to compare the effectiveness of mindfulness-based cognitive therapy and metacognitive therapy and combination of these two therapies on procrastination and bullying behavior of adolescent girls. Method: The design of this study was quasi-experimental with pretest-posttest with a control group. The instruments included procrastination assessment scale for students of Solomon and Rothblum (1984) and cyberbullying and online aggression survey of Patchin and Hinduja (2011) and the children's acceptance and mindfulness measure, meta-cognitions questionnaire for adolescents. The sample consisted of 60 subjects whose procrastination and bullying scores were higher than 2 the average. The subjects were divided into three test groups and one control group. Results: results of analysis of variance showed that metacognitive therapy, mindfulness-based therapy and metacognitive + mindfulness therapy were effective in reducing procrastination and bullying behavior of students. There is a significant difference between pretest, posttest and follow-up scores of the test and control groups. Conclusion: results of the follow-up test confirmed stability of the changes.