Introduction: The emotional schema model emphasises on mind rumination and other emotional schemas in depression. This study aimed to determine the effectiveness of Emotional Schema Therapy (EST) on severity of depression and rumination in people with major depression disorder.

Methods: This was a randomized controlled trial study using pre-test and post-test-follow up with the control group. Among all patients with major depressive disorder visited in Imam Hossein hospital and Rahyar clinic of Tehran, 32 patients were selected through inclusion or exclusion criteria and convenience sampling then they were randomly assigned into two equal groups; experimental (16 persons) and control (16 persons). Experimental group experienced 14 weeks of emotional schema therapy, while the control grouprecieved no treatment intervention. Revised Beck depression inventory (BDI-II) and ruminative response scale (RRS) were used in base lines, post-test and follow up as the assessment instruments. Data were analyzed by mixed analysis of variance via SPSS₁₉ software.

Results: The results of this research showed that the means of depression and rumination in the experimental group were reduced significantly in comparison with the control group in post-test and follow up (P<0.05).

Conclusion: The study findings proposed that Emotional Schema Therapy can be used as an effective intervention in order to reduce the depression and mind rumination in people with major depressive disorder.