Autism is being diagnosed earlier in young children, especially in boys, according to a major new analysis of medical records published on Tuesday.
Conducted by Epic Research -- the data and analytics arm of the electronic health record software company, Epic Systems -- the analysis also found that many girls still face years-long delays in receiving a diagnosis and an increasing share of women are not diagnosed until adulthood.
This raises concerns about missed opportunities for early support, Dr. Catherine Lord, the George Tarjan Distinguished Professor of Psychiatry and Education in the David Geffen School of Medicine at UCLA, told ABC News.
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"There is evidence that girls are often diagnosed later than boys, and particularly girls with milder symptoms are missed entirely," Lord, who was not involved in the analysis, said. "When you add in adults seeking a diagnosis later in life -- often more women than men -- it pushes the average age of diagnosis for females even higher."
The study reviewed records from more than 338,000 patients who received their first autism spectrum disorder diagnosis between 2015 and 2024, using aggregated electronic health record data from hospitals and clinics nationwide to study health care trends. While not peer-reviewed, Epic Research's work is vetted internally by the company's clinical and research experts.
The median age at diagnosis for all children fell from age 7 in 2015 to age 6 in 2024, the analysis suggested. For boys, the median age dropped from age 7 to age 5, with nearly half diagnosed before age 5 in 2024.
Girls showed no similar shift, the analysis found. Their median age of diagnosis remained at about age 8, and only about one-third were diagnosed before age 5. The disparity persisted into adulthood, with one in four women first diagnosed at age 19 or older, compared with about one in eight men, the analysis found.
Although the median age for diagnosis dropped, the average age remained at about 10.5 years old, likely implying that some people were being diagnosed much later, potentially into adulthood.
Early detection matters because therapies, school accommodations, and interventions -- often involving speech-language pathologists, occupational therapists and developmental pediatricians -- are most effective when started early in life, Lord explained.
"The biggest time of change particularly in developing language, is in the early years," Lord said. "Interventions can speed up learning and help prevent later anxiety and depression by making life easier for autistic kids and their families."
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Early signs of autism can include limited eye contact, not responding to their name, delayed speech, repetitive behaviors such as hand-flapping or lining up objects, intense or unusual interests, and distress over changes in routine, according to the Centers for Disease Control and Prevention (CDC) ,
In girls, these signs may be harder to notice or focused on socially typical topics, which can delay recognition.
For families facing barriers to diagnosis, Lord recommended seeking evaluations through schools, contacting state-run early intervention programs for children under age three. She also recommended relying on credible sources such as the CDC, Autism Speaks and the Autism Science Foundation for more information.
"There's much more hope now for autism," she said. "Not to 'cure' it, but to support people, figure out their strengths, and help them find their place in the world."
Christian S. Monsalve, MD is a functional psychiatry fellow and a member of the ABC News Medical Unit.
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