A quarterly publication of the Autism Research Institute

The Autism Research Review International is quarterly publication of the Autism Research Institute

Winter, 2020 | Number 1, Volume 34

Large-scale study: co-existing conditions are very common in ASD; girls receive diagnoses significantly later than boys

A large-scale study shows that girls with autism spectrum disorders (ASD) typically receive a diagnosis much later than boys, and that individuals with ASD have high rates of co-occurring disorders. 

Carolyn McCormick and colleagues analyzed data from the first 1,000 participants in the Rhode Island Consortium for Autism Research and Treatment (RI-CART). The researchers found that girls with ASD are diagnosed on average nearly 1.5 years later than boys. The researchers speculate that this is because girls with ASD tend to have more advanced language skills compared to boys. 

Study coauthor Eric Morrow comments, “The major treatment that has some efficacy in autism is early diagnosis and getting the children into intensive services, including behavioral therapy. So if we’re identifying girls later, that may delay their treatment.” 

In addition, the researchers found that individuals with ASD frequently have comorbid conditions. Nearly half of the participants had another neurodevelopmental disorder such as attention-deficit/hyperactivity disorder (ADHD) or intellectual disability. In addition, 44.1 percent had a psychiatric disorder, 42.7 percent had a neurological condition such as epilepsy, migraines, or tics, and 92.5 percent reported at least one general medical condition. 

The researchers conclude, “Psychiatric and medical comorbidities in ASD constitute a substantial burden and warrant adequate attention as part of overall treatment.”


“Autism heterogeneity in a densely sampled U.S. population,” Carolyn E. B. McCormick, Brian C. Kavanaugh, Danielle Sipsock, Giulia Righi, Lindsay M. Oberman, Daniel Moreno De Luca, Ece D. Gamsiz Uzun, Carrie R. Best, Beth A. Jerskey, Joanne G. Quinn, Susan B. Jewel, Pei-Chi Wu, Recbecca L. McLean, Todd P. Levine, Hasmik Tokadjian, Kayla A. Perkins, Elaine B. Clarke, Brittany Dunn, Alan H. Gerber, Elena J. Tenenbaum, Thomas F. Anders, Stephen J. Sheinkopf, and Eric M. Morrow, Autism Research, January 20, 2020 (epub prior to print publication). Address: Eric Morrow, [email protected], or Stephen Sheinkopf, [email protected]


“Autism study finds later diagnoses for girls, high rates of co-occurring disorders,” news release, Kerry Benson, Brown University, January 21, 2020.