This study examined lifetime medical and psychiatric morbidity reported by caregivers of 2917 autistic adults participating in the US research cohort SPARK. Participants were 78.4% male, 47.3% had intellectual disability, and 32.1% had persistent language impairments. Childhood language disorders (59.7%), speech/articulation problems (32.8%), sleep (39.4%) and eating problems (29.4%), motor delays (22.8%) and history of seizure (15.5%) were the most frequently reported clinical features. Over two thirds (67.2%) had been diagnosed with at least one psychiatric disorder (anxiety disorders: 41.1%; ADHD: 38.7%). Compared to verbally fluent participants, those with language impairments had lower frequencies of almost all psychiatric disorders. Female sex and older age were associated with higher medical and psychiatric morbidity.
Keywords: Adult; Autism; Autism spectrum disorder; Intellectual disabilities; Medical; Psychiatric; SPARK; Sex.