Family History of Mental and Neurological Disorders and Risk of Autism

Key Points Question Is family history of mental and neurological disorders associated with risk of autism spectrum disorders, and does this vary with vs without intellectual disability? Findings In this population-based cohort study of 567 436 Swedish participants, positive family history was associated with increased risk of autism spectrum disorders. Autism spectrum disorders with intellectual disability exhibited a weaker familial association with other mental disorder diagnoses but a stronger familial association with some neurological diagnoses as compared with autism spectrum disorders without intellectual disability. Meaning This study suggests that family history of mental and neurological disorders is associated with autism risk, and the familial component of autism etiology may differ by presence or absence of co-occurring intellectual disability.