TOPLINE

Diagnoses of autism spectrum disorder (ASD) in US adults and children rose from 2020 to 2024, driven predominantly by a significant 19% annual increase in female patients, a new cohort study showed. However, ASD incidence during that time period remained stable or declined in male patients.

METHODOLOGY

• A retrospective cohort study used electronic health record data for patients in Illinois, Missouri, Oklahoma, and Wisconsin from 2016 to 2024.
• More than 171,000 participants (mean age, 26.8 years; 63.8% female; 81.5% White) with continuous annual healthcare engagement were included, with more than 40,000 classified as children (age, 0-9 years), more than 21,000 as adolescents (age, 10-18 years), and more than 109,000 as adults (age, 19-50 years).
• The primary outcome was newly recorded diagnoses for ASD or Asperger disorder.
• Temporal trends in annual incidence of newly recorded ASD diagnoses were assessed using models stratified by age group and sex.

TAKEAWAY

• The overall incidence of an ASD diagnosis in the entire study population decreased from 2016 to 2020 (annual percentage change [APC], -6.8) but increased from 2020 to 2024 (APC, 7.1). Among female patients, ASD incidence increased significantly after 2020 (APC, 19.0%), whereas incidence among male patients declined throughout the study period (APC, -3.8%).
• Gender patterns were similar in the pediatric cohort, with a decreasing incidence of ASD in boys (APC, -2.0%) and a rising incidence in girls since 2020 (APC, 17.4%).
• In adolescent girls, ASD incidence increased significantly from 2020 to 2024 (APC, 22.3%), whereas in adolescent boys, it declined from 2016 to 2018 (APC, -29.6%) and remained stable from 2018 to 2024.
• The mean age at ASD diagnosis was significantly lower among male vs female patients (12.3 years vs 15.7 years; P < .001).

IN PRACTICE

“These patterns suggested that increasing ASD prevalence reflected improved identification of historically underrecognized presentations rather than a uniform population-level increase,” the investigators wrote.

“These findings highlight the need for screening strategies that address sex-specific presentations,” they added.

SOURCE

The study was led by Erick Messias, MD, PhD, School of Medicine, Saint Louis University, St. Louis. It was published online on July 22 in JAMA Network Open.

LIMITATIONS

The study was limited by reliance on diagnostic codes, potential overrepresentation of individuals with stable insurance coverage and regular access to care, underrepresentation of those with lower socioeconomic status or fragmented health care use, a predominantly non-Hispanic White population, and a lack of standardized measures of intellectual functioning. Additionally, data were drawn from a single large Midwestern health care system, limiting the generalizability of the findings.

DISCLOSURES

Disclosure information for the study investigators is available in the original study publication.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.