effectiveness of metacognitive therapy in reducing psychological and metacognitive factors in patients with major depressive disorder in a military hospital

purpose: to investigate the effectiveness of metacognitive therapy in patients with major depressive disorder. the population of this study included all patients admitted to the army hospital no. 520 diagnosed with major depressive disorder from which 30 individuals were selected by using random sampling into experimental and control groups (n = 15 experimental and n = 15 control). materials and methods: the research method was a quasi-experimental design in which pretest andpost-test with control group design was used. the instrument consists of metacognitive therapy, beck depression inventory (bdi-ii) and the metacognition questionnaire (mcq-30). data were analyzed with inferential statistics methods including t-test for independent groups and analysis of covariance. results: results in this study showed that meta-cognitive therapy reduces emotional symptoms (sadness, frustration, guilt, self-loathing, crying, restlessness, social withdrawal and irritability), cognitive symptoms (pessimism, expectation of failure, feeling of punishment, self-accusation, suicidal thoughts, indecisiveness, worthlessness, and difficulty in concentration), physical symptoms (disability, change in sleep patterns, fatigue, change in appetite and sexual interest) and metacognitive beliefs. conclusion: this study showed that metacognitive therapy is an effective method in reducing symptoms of major depressive disorder and should be considered within the treatment of the aforementioned disorder.