A new Saint Louis University study of nearly a decade of health records finds that the recent rise in autism spectrum disorder (ASD) diagnoses is being driven largely by girls and women, who are being identified at significantly higher rates than in years past, often years later than boys and men. The JAMA Network study, led by Erick Messias, M.D., Ph.D., chair and professor of Psychiatry and Behavioral Neuroscience at Saint Louis University School of Medicine, analyzed electronic health records for 171,134 patients across a large Midwestern healthcare system from 2016 to 2024. It is among the first to track sex-specific autism diagnosis trends across childhood, adolescence and adulthood within the same health system, before and after the COVID-19 pandemic.