A study by researchers at Columbia University Mailman School of Public Health and the New York State Psychiatric Institute in collaboration with the Kaiser Permanente Division of Research reports an association between smoking during pregnancy and increased risk for developing bipolar disorder (BD) in adult children. The paper evaluated offspring from a large cohort of pregnant women who participated in the Child Health and Development Study (CHDS) from 1959-1966. The study was based on 79 cases and 654 comparison subjects. Maternal smoking during pregnancy was associated with a twofold increased risk of BD in their offspring. Findings are published in the American Journal of Psychiatry.