Rise in autism diagnoses among girls signals shift in detection and awareness

Recent studies reveal a sharp increase in autism diagnoses among girls and women in the US, prompting changes in recognition, diagnosis practices, and understanding of gender differences in autism presentation.

The sharpest recent rise in US autism diagnoses is now being recorded among girls and women, not boys, according to a Saint Louis University study published in JAMA Network Open in July. The analysis of 171,134 patients in one Midwestern health system found female diagnoses climbing markedly after 2020 across children, adolescents and adults, while new diagnoses among males were flat or falling. Even so, females were still identified an average of 3.4 years later, at 15.7 compared with 12.3 for males.

That shift sits against a broader rise in autism identification. US Centers for Disease Control and Prevention data show about one in 31 children aged eight had been identified with autism in 2022, up from one in 68 in 2010, and boys are still reported as more than three times as likely as girls to be identified. But a large Swedish study reported by The Guardian suggests the gap looks smaller over a lifetime than it does in childhood. Following 2.7 million people born between 1985 and 2020, researchers found 2.8% were diagnosed between ages two and 37, and by age 20 diagnosis rates for males and females were close to equal. In childhood, however, boys were diagnosed almost three years earlier on median, and were three to four times as likely to be identified before age 10.

US health record data point in the same direction. An Epic Research analysis of more than 338,000 first autism diagnoses between 2015 and 2024, reported by ABC News, found the median age at diagnosis for all children fell from seven to six. For boys it dropped from seven to five, with nearly half diagnosed before five by 2024. Girls showed little comparable movement: their median diagnosis age stayed around eight, only about one-third were diagnosed before five, and one in four women were first diagnosed at 19 or older, compared with roughly one in eight men. Catherine Lord of UCLA told ABC that “girls with milder symptoms are missed entirely”.

Part of the reason is that many autistic girls do not fit the profile clinicians were trained to spot. Autism Speaks says girls and women may show better reciprocal conversation, be better at reading and mimicking social cues, and display less obvious repetitive behaviour. Their intense interests can also look conventional rather than unusual: animals, celebrities, dolls or unicorns may draw less concern than the highly specific obsessions more often associated with autistic boys. The Los Angeles Times reported that boys and girls are diagnosed at broadly similar rates until about age three, when children with clearer language or developmental delays are easiest to identify. After that, the gap widens through the school years as girls’ traits are more readily mistaken for shyness, sensitivity or simply fitting in.

That ability to blend in comes at a cost. Autism Speaks describes masking as forcing eye contact, suppressing stimming, rehearsing conversations and hiding special interests. The practice can delay diagnosis and is linked to anxiety, depression, stress and suicidality. The Los Angeles Times reported that autistic girls without intellectual disability are more likely than boys to be diagnosed first with depression or anxiety before autism is recognised, missing the earlier support that might have helped them manage school, friendships and sensory overload.

The human consequences are stark. The Los Angeles Times recently told the story of Ruby Hobbs-Leffler, who died by suicide in 2024 at 15 after receiving an autism diagnosis at 14. Her mother, Jessica Leffler, said of the years her daughter spent trying to pass as typical: “She masked, she masked, she masked.” Leffler has questioned why a girl who had sensory sensitivities, rigid routines and major distress in childhood was treated for individual problems without professionals joining them up sooner.

Campaigners and clinicians say that pattern is not simply about biology but about how autism has been defined and assessed. Writing in response to the Swedish study, Anne Cary argued that the disparity reflected systemic bias in diagnosis rather than a true difference in incidence. Judith Brown of the National Autistic Society said women and girls are more likely to hide what are traditionally treated as autistic traits, while Jolanta Lasota of Ambitious about Autism said they have “slipped under the radar for far too long”. Conor Davidson, former autism champion at the Royal College of Psychiatrists, said signs in girls may not become obvious until adolescence or early adulthood, when social demands become harder to script.

Taken together, the newer studies suggest a more complicated picture than the old shorthand of autism as mainly a condition of boys. Girls are still being identified later and less often in childhood, but recent data indicate that services are beginning to catch up, particularly after the pandemic, as clinicians recognise subtler female presentations. The challenge now is whether that recognition reaches children early enough to prevent years of missed support, mistaken mental health labels and avoidable crisis.