Children whose mothers smoked during pregnancy are at increased risk for psychotic symptoms by age 12, according to a longitudinal study in the British Journal of Psychiatry.

Researchers gathered information on women’s use of tobacco, alcohol, and cannabis during pregnancy and then evaluated their offspring for psychotic symptoms 12 years later. Of nearly 6400 children assessed, about 12% had suspected or definite psychotic symptoms.

In adjusted analyses, maternal smoking was associated with increased risk for psychotic symptoms in offspring, with a dose-response effect (odds ratio for trend, 1.2). A link between alcohol use and psychotic symptoms was limited to mothers who consumed more than 21 units a week. Cannabis use was not associated with symptoms.

The authors say their findings are “consistent with accumulating evidence from animal models of adverse effects on brain development from in utero nicotine exposure.”

Spurce: British Journal of Psychiatry