Mahboubeh Sabaghi - Department of Psychiatry, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
Gita Sadighi - Department of Psychiatry, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
Mohammad Reza Khodaei Ardakani - Department of Psychiatry, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
Bahman Dieji - Department of Psychiatry, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
Mehdi Nowrouzi - Department of Statistics, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
Maryam Aghaye Rashti - Department of Statistics, Shahid Beheshti University, Tehran, Iran.
Sasan Zandi Esfahan - Department of Nursing and Midwifery, Najafabad Branch, Islamic Azad University, Isfahan, Iran.

Objectives: The effect of metformin on weight changes and some metabolic parameters in patients with schizophrenia and schizoaffective disorder was investigated in this study. Methods: As a randomized double-blind controlled clinical trial, this study was performed from ۲۰۱۸ to ۲۰۱۹. A total of ۶۶ obese patients (BMI≥۲۷) with schizophrenia and schizoaffective disorder, hospitalized in the departments of Razi Psychiatric Hospital, entered the study; then, they were randomly divided into intervention and control groups after completing the informed consent form. The patients received metformin or placebo for ۱۲ weeks. The dose of metformin was gradually increased and in case of a patient’s tolerance, was prescribed up to ۵۰۰ mg twice daily. During the study, all patients received their previous therapies. The variables included BMI, weight, waist circumference, lipid profile, and fasting blood glucose, which were studied at the beginning of the study and at weeks ۴, ۸, and, ۱۲. The data were analyzed, using a post hoc test by SPSS software. Results: The results showed a significant decrease in weight (۳.۵ kg) and BMI (۱.۳۰) at the end of the week ۱۲, and there was a significant reduction in waist circumference (۵.۹ cm) at the end of the week ۸ compared to the placebo group (P<۰.۰۵). Moreover, metformin had no significant effect on fasting blood glucose and lipid profile in comparison with the placebo group. Discussion: Based on the findings of this study, by reducing the weight, waist circumference, and BMI, metformin can have a significant role in decreasing the complications of obesity and metabolic disorders in patients with schizophrenia and schizoaffective disorder. Therefore, given that the complications of metformin are low and transient, it can be recommended as a safe and tolerable drug in obese patients with schizophrenia and schizoaffective disorder.

Schizophrenia, Schizoaffective disorder, Obesity, Metformin, Antipsychotics