The aim of this research was to investigate the effectiveness of rumination-focused cognitive behavioral therapy on interpretation bias in adolescent girls with depressive disorder. The study community included all female adolescents studying in the age range of 15 to 18 years in Ramshir City in 2023-2024. From the aforementioned population, a sample of 350 people was selected using Sample available and completed the Beck Depression Inventory, of which 28 people scored above the cutoff point (score higher than 25). Then, this group underwent a diagnostic interview and completed the Amir et al. (1998) Interpretation Bias Questionnaire as a pre-test. Both groups were randomly assigned into two experimental groups and a control group. The present research design was a semi-experimental pre-test-post-test type with a control group. The experimental group underwent rumination-focused cognitive behavioral therapy, but the control group did not receive any intervention. The results showed that rumination-focused cognitive behavioral therapy was effective in reducing interpretation bias in adolescent girls with depressive disorder. According to the findings of the present study, it can be concluded that rumination-focused cognitive behavioral therapy can be used as an effective method to help improve the conditions of adolescent girls with depressive disorder.
