Metformin for the prevention of clozapine-induced weight gain: A retrospective naturalistic cohort study.

In this large retrospective naturalistic cohort study, co-prescription of clozapine and metformin was associated with less weight gain and related metabolic dysfunction at 6 and 12 months after initiation versus clozapine alone. These findings provide evidence for the effectiveness of metformin in preventing clozapine-induced weight gain; larger randomized controlled trials are needed to confirm these results.