Key clinical point: Patients with polycystic ovary syndrome (PCOS) are at an increased risk of incident schizophrenia; treatment with metformin has protective effect against incident schizophrenia.

Major finding: Patients with PCOS had an increased risk of incident schizophrenia compared with non-PCOS control participants (0.49 vs. 0.09 per 1,000 person-years; hazard ratio [HR], 6.93; P less than .05). Metformin treatment had a protective effect against incident schizophrenia (HR, 0.16; P less than .05).

Study details: A Taiwanese population-based cohort study of 7,146 patients with PCOS and 28,580 matched non-PCOS controls.

Disclosures: The study was supported, in part, by the Taiwan Ministry of Health and Welfare Clinical Trial Center; MOST Clinical Trial Consortium for Stroke, Taiwan; Tseng-Lien Lin Foundation, Taichung, Taiwan. The authors declared no conflicts of interest.