Fifty-eight patients who received metformin and 58 who received placebo completed 16 weeks of treatment. Mean change in body weight was −3.0 kg for the metformin group and −1.0 kg for the placebo group. Metformin also demonstrated a significant between-group advantage for body mass index, triglyceride level, and hemoglobin A1c level. Metformin-associated side effects were mostly gastrointestinal and generally transient.
“Metformin was modestly effective in reducing weight and other risk factors for cardiovascular disease in clinically stable, overweight outpatients with chronic schizophrenia or schizoaffective disorder over 16 weeks,” the researchers concluded. “A significant time-by-treatment interaction suggests that benefits of metformin may continue to accrue with longer treatment.”
For more on the subject of psychosis and weight gain, see Psychiatric News here.