Girls and autism are often missed in childhood

A Swedish study of nearly 2.8 million people over 35 years found boys under 10 were three to four times more likely to be diagnosed with autism than girls, yet by adulthood the diagnostic gap largely disappeared, suggesting many autistic girls are missed in childhood.

A large Swedish study reviewed 35 years of health records for nearly 2.8 million people and found striking age-related differences in autism diagnosis. Boys under 10 were three to four times more likely than girls to receive an autism diagnosis, but that gap largely disappeared by adulthood. Experts say the pattern indicates many autistic girls are not identified in childhood. Researchers and commentators point to differences in how traits present and to camouflaging as reasons those girls are often missed. Key findings: - The study used decades of Swedish health records covering nearly 2.8 million people and compared diagnosis rates by age and sex. - Boys under age 10 were diagnosed with autism three to four times more often than girls; by adulthood the difference was much smaller. - Girls’ autistic traits are often described as milder or different in expression, including better eye contact or communication in some cases, which can make them less visible to clinicians and teachers. - Many girls use camouflaging or masking strategies that help them appear to fit in early on but can break down in adolescence; a 2024 study found teachers often reported fewer autism traits in girls than parents did. - Girls who are not recognized as autistic in childhood are sometimes diagnosed later with other conditions, and one study found an ADHD diagnosis can delay an autism diagnosis by nearly three years on average. Summary: The findings suggest a substantial number of autistic girls are overlooked during childhood, which can delay access to supports and lead to different or later diagnoses. Researchers and commentators call for more study, better diagnostic tools that capture subtler presentations, and greater awareness among clinicians and educators to better understand and identify autistic girls.