Autism severity aggregates with family psychiatric history in a community-based autism sample

The purpose of this study was to examine family psychiatric history in individuals with autism spectrum disorder (ASD) and its association with clinical presentation. Participants were 798 individuals with a clinical diagnosis of ASD, confirmed by the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2), enrolled in Rhode Island Consortium for Autism Research and Treatment, a statewide research registry. Prior research suggests a specific behavioral phenotype in individuals with ASD who have family members with psychiatric diagnoses, including higher IQ and less severe language impairment. However, studies have not specifically investigated autism severity. We hypothesized that increased psychiatric family history would be associated with increased autism severity symptoms. Results show a strong association of increased burden of first-degree family psychiatric history with higher autism symptom severity as measured by Social Responsiveness Scale, Second Edition (SRS-2), but not with ADOS-2 severity scores, IQ, or adaptive functioning. These findings support the importance of investigating the contribution of psychiatric family history toward clinical ASD presentation. LAY SUMMARY: This study explored how family psychiatric history is related to clinical presentation of Autism Spectrum Disorder (ASD). Higher amounts of first-degree family psychiatric history was associated with higher autism symptom severity as measured by the Social Responsiveness Scale, Second Edition (SRS-2). The contribution of psychiatric family history requires ongoing investigation.