Prenatal exposure to some antidepressants is linked to a modest increased risk of autism spectrum disorder, U.S. researchers say. Lisa A. Croen of Kaiser Permanente Northern California in Oakland, Calif., and colleagues examined medical records for children from the Childhood Autism Perinatal Study conducted by Kaiser Permanente Medical Care Program in Northern California. The study involved 298 children with autism spectrum disorder and their mothers, and 1,507 control children and their mothers. Twenty mothers of children in the autism group, 6.7 percent, and 50 mothers of children in the control group, 3.3 percent, had at least one prescription for an antidepressant in the year prior to the birth of the child involved in the study. Of the 20 case mothers who were prescribed antidepressants, 65 percent were prescribed selective serotonin reuptake inhibitors only, 10 percent were prescribed a selective serotonin reuptake inhibitor in combination with another antidepressant and 25 percent were prescribed one or more non-selective serotonin reuptake inhibitor antidepressants only. Of the 50 control mothers who were prescribed an antidepressant, 50 percent were prescribed selective serotonin reuptake inhibitors only, 18 percent were prescribed an selective serotonin reuptake inhibitor in combination with another antidepressant and 32 percent were prescribed one or more non-selective serotonin reuptake inhibitors antidepressants only. The study, published in Online First in the Archives of General Psychiatry, found mothers of children with autism spectrum disorder were twice as likely as others to have at least one antidepressant prescription in the year prior to delivery.