Overview
- Using Swedish national registers, the BMJ study tracked 2.7 million people born between 1985 and 2022, identifying 78,522 autism diagnoses (2.8%) at an average age of 14.3.
- Diagnosis rates peaked for boys at ages 10–14 and for girls at 15–19, revealing a clear adolescent catch-up among females.
- By about age 20, the male-to-female diagnosis ratio approached 1:1 in the cohort, challenging long-cited childhood ratios of 3–4 to 1.
- The authors note limitations, including the inability to control for shared genetics and environment or co-occurring conditions such as ADHD and intellectual disability, and sparse outpatient data before 2001.
- Commentators cite masking and systemic diagnostic bias as likely factors in later recognition for girls, warning of misdiagnosis and mental-health harms and urging better pathways and support for women and girls.