Autism is a pervasive developmental disorder characterized by abnormalities in social interaction, communication, and behavior (repetitive/perseverative behaviors). The cause is unknown and treatments limited.
Two recent epidemiological studies have shown a doubling to tripling incidence of autism spectrum disorder (ASD) in children born to women who took antidepressants during pregnancy. One of the studies found that the largest risk was from selective serotonin reuptake inhibitors (SSRIs), the largest group of antidepressants. Unfortunately, studies of this type cannot determine which antidepressant(s) may be causing ASD or if non-SSRI antidepressants are similarly associated with ASD risk. Nor can human studies determine the molecular mechanisms of how antidepressants alter the developing brain to increase the risk of ASD. We are testing the effects of two SSRI and one non-SSRI antidepressant given during brain development in laboratory rats (from implantation to the end of neurogenesis) to assess how the drugs affect brain development, neurotransmitters, receptors, and ASD-like behavior. So far we find that SSRI antidepressants cause compulsive behavior, reduced responses to sudden loud tones (indicative of a sensorimotor gating abnormality), and learning and memory impairment in the offspring whereas non-SSRIs do not. This may have implications for those taking antidepressants during pregnancy. If verified in human studies, this could lead to changes to prescribing recommendations for those who are or may become pregnant.