News Release

Age at autism diagnosis differs between boys, girls

Study shows females also have different symptoms than males, possibly contributing to later identification, under-identification

Peer-Reviewed Publication

American Academy of Pediatrics

SAN DIEGO - Girls are diagnosed with autism spectrum disorder (ASD) later than boys, possibly because females exhibit less severe symptoms, according to a study to be presented Tuesday, April 28 at the Pediatric Academic Societies (PAS) annual meeting in San Diego.

To study gender differences in age at diagnosis and compare symptom severity between boys and girls, researchers at the Kennedy Krieger Institute in Baltimore, Md., analyzed data from the Institute's Interactive Autism Network. This online registry includes almost 50,000 individuals and family members affected by ASD who work with researchers to better understand the nature of the disorder. In the registry, age of first diagnosis was available for 9,932 children, and 5,103 had completed the Social Responsiveness Scale, which identifies the presence and severity of social impairment.

In the data review, researchers found girls were diagnosed with pervasive developmental disorder, an ASD impacting the development of many basic skills, at a mean age of 4 years compared to 3.8 years for boys. This also was the case with girls diagnosed with Asperger's syndrome; girls were diagnosed at a mean age of 7.6 years for the condition, which affects language and behavioral development, vs. 7.1 years for boys.

In addition, they found girls struggled more with social cognition -- the ability to interpret social cues. Meanwhile, boys had more severe mannerisms such as repetitive behaviors like hand flapping, as well as highly restricted interests. Older boys, ages 10-15, also had more difficulties with the ability to recognize social cues and use language in social situations.

"This and other studies suggest that girls with ASD, as well as perhaps older women with this disorder, differ from males in key symptoms and behaviors, particularly around social interactions," said Paul Lipkin, MD, FAAP, study author and director of the Interactive Autism Network at Kennedy Krieger. "We must determine if the less recognizable symptoms in girls are leading not only to delayed diagnosis, but also under-identification of the condition."

Researchers also saw an increase in the proportion of girls who were diagnosed with ASD in 2010-2013 when compared to 2006-2009. Dr. Lipkin, a neurodevelopmental pediatrician who also serves as director of medical informatics at Kennedy Krieger, believes this increase may be due to growing public awareness and that screening methods and treatment strategies may need to be modified to meet the needs of each gender.

Dr. Lipkin will present "Gender Differences in Diagnosis and Social Characteristics of Children with Autism (ASD) from a U.S. Registry" from 10-10:15 a.m. PT on Tuesday, April 28. To view the study abstract, go to


This study was supported by a grant from Johns Hopkins Medicine International (SYSU-JHU Pilot Grant Program on Clinical and Translational Research).

About the Interactive Autism Network (IAN)

Launched in 2007, the IAN Project connects individuals on the autism spectrum and their families with researchers nationwide to accelerate the pace of autism research and aid advocacy efforts for improved services and resources. Housed at the Kennedy Krieger Institute in Baltimore, Md., this innovative online initiative has nearly 50,000 participants who contribute information to create the largest pool of autism data in the world. For more information or to join the search for answers, visit

About Kennedy Krieger Institute

Internationally recognized for improving the lives of children and adolescents with disorders and injuries of the brain, spinal cord and musculoskeletal system, the Kennedy Krieger Institute in Baltimore, Md., serves more than 20,000 individuals each year through inpatient and outpatient clinics, home and community services and school-based programs. Kennedy Krieger provides a wide range of services for children with developmental concerns mild to severe, and is home to a team of investigators who are contributing to the understanding of how disorders develop while pioneering new interventions and earlier diagnosis. For more information on the Kennedy Krieger Institute, visit

The Pediatric Academic Societies (PAS) are four individual pediatric organizations that co-sponsor the PAS Annual Meeting - the American Pediatric Society, the Society for Pediatric Research, the Academic Pediatric Association, and the American Academy of Pediatrics. Members of these organizations are pediatricians and other health care providers who are practicing in the research, academic and clinical arenas. The four sponsoring organizations are leaders in the advancement of pediatric research and child advocacy within pediatrics, and all share a common mission of fostering the health and well-being of children worldwide. For more information, visit Follow news of the PAS meeting on Twitter at @PASmeeting and Facebook at Use hashtag #PASMEETING.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.