Insights from Two Decades of Statewide Data on the Diagnostic Rates among Autistic Females

A 2024 study by Harrop and colleagues reflects how the landscape of autism diagnosis for females has evolved. Drawing on more than 10,000 diagnostic records from the TEACCH Autism Program in North Carolina, spanning the years 2000 to 2021, the study reveals a steady increase in the proportion of females identified as autistic. Although the male-to-female ratio narrowed over this period, the study found that females are still diagnosed later than males, particularly those without co-occurring intellectual disability. These findings point to both progress and persistent challenges. While diagnostic pathways are becoming more inclusive, late recognition remains a concern, highlighting the ongoing need for approaches that acknowledge the diversity of autistic experience.

More autistic girls and women are being diagnosed, but timely recognition remains an urgent priority.

Reframing Gender in Autism

Autism has long been framed as a predominantly male condition, an idea that has influenced research, clinical practice, and cultural perceptions. Traditional diagnostic criteria and assessment tools were developed based on studies of boys and men, with male-typical traits seen as the gold standard (Loomes et al, 2017, Bargiela et al., 2016; Lai et al., 2022)). As a result, many autistic females were overlooked, misunderstood or mislabelled, and their support needs often unmet. Over the last decade, this narrative has started to shift. Advocates and researchers have drawn attention to the many ways that autism can be expressed, particularly among those whose characteristics do not fit traditional descriptions. Studies suggest that autistic females are more likely to use strategies such as camouflaging or masking in social situations and may develop interests and routines that differ from autistic male presentations (Bargiela et al., 2016; Lai et al., 2017; Hull et al., 2020). It has been suggested that these differences have contributed to delayed or missed diagnoses, and a sense of being misunderstood or unsupported within healthcare and educational systems. The work by Harrop and colleagues builds on this changing understanding, asking whether more autistic females are being recognised today than in the past. It also explores whether changes in diagnostic practice, including the adoption of broader criteria, have influenced who receives an autism diagnosis and at what stage of life.

Embracing the diversity of autistic experiences challenges outdated stereotypes and opens new pathways to support.

What Did the Study Find?

The TEACCH Autism Program, serving the entire state of North Carolina, provided a unique window into diagnostic patterns over two decades. The research team reviewed the records of more than 10,000 people diagnosed between 2000 and 2021. This large, community-based sample included both children and adults and captured a range of lived experiences across gender, age, and intellectual profiles. One of the most striking findings is the clear increased trend in the proportion of females receiving an autism diagnosis. In the early 2000s, the male-to-female diagnostic ratio stood at more than five to one. By 2021, that gap had narrowed, with just over three males diagnosed for every female. This trend is not unique to North Carolina; similar shifts have been reported in other regions, reflecting growing awareness among clinicians, families, and communities. Yet, the study highlights that autistic females are still diagnosed later on average than their male counterparts. This delay was even more pronounced among females without co-occurring intellectual disability, suggesting that more less “classic” presentations may continue to go unrecognised in early childhood. A significant portion of females received their first autism diagnosis in adolescence or even adulthood, a pattern far less common among males. The research also explored the potential impact of changing diagnostic criteria, particularly the transition from DSM-IV to DSM-5 in 2013. Interestingly, the analysis found that the increase in female diagnoses was not simply a result of broader definitions or official guidelines. Rather, it appears that wider societal awareness, enhanced clinical sensitivity, and evolving conceptions of what autism can look like have played a larger role.

Changing diagnostic patterns reflect not only new criteria but deeper shifts in understanding and awareness.

What Do These Findings Mean for Autistic Females and Their Communities?

For many autistic people, early recognition can be transformative, opening the door to support, community, and a positive sense of identity. The narrowing of the gender gap in diagnosis signals an important step toward equity, yet the continued delays for females raise critical questions about how autism is recognised and understood. Harrop and colleagues point to several reasons why autistic females are still less likely to be diagnosed early. One factor is that assessment tools and professional training often remain anchored in male-centric assumptions, leading to missed or mistaken identification. Many autistic girls and women develop ways of navigating social situations, sometimes masking their differences at great personal cost. Others may present with interests or coping strategies that do not fit clinical expectations. In some cases, the presence of co-occurring mental health conditions such as anxiety or ADHD can further obscure the picture, resulting in “diagnostic overshadowing.”

For those who are identified later in life, the journey to diagnosis can be marked by frustration, misunderstanding, and a sense of isolation. However, many late-identified autistic women describe their diagnosis as a moment of clarity and self-acceptance and an opportunity to reframe past experiences and access new forms of support. The study underscores the need for professionals to listen deeply to the voices and stories of autistic females, and to ensure that identification is not limited by outdated models or stereotypes.

Listening to lived experience and challenging assumptions are keys to timely, affirming diagnosis.

Building a More Inclusive Future

The authors of the study are clear that while substantial progress has been made, important work remains. To ensure that all autistic people, regardless of gender, have access to timely, accurate, and affirming diagnosis, multiple steps are needed. Professional training must continue to evolve, by training clinicians to recognise the full spectrum of autistic presentations and to move beyond rigid categories. Assessment tools should be refined and validated to capture diversity across age, gender, and cognitive profile. The perspectives of autistic females and non-binary people should be included at every stage of research, policy, and practice. Their insights are vital for designing supports that are truly responsive to the needs and preferences of those they are meant to serve. Future research should continue to explore the factors that contribute to delayed or missed diagnoses, with particular attention to how intersections of gender, race, and class shape these experiences.

A neurodiversity-affirming future recognises every person’s strengths and challenges.

Conclusions

The last two decades have brought meaningful change in how autism is recognised and diagnosed among females. The narrowing of the diagnostic gender gap reflects both a greater awareness and acceptance, and the persistence of late identification. By committing to ongoing learning, challenging stereotypes, and centering the voices of autistic people themselves, researchers, clinicians, and advocates can help create a better understanding of diversity.

Where next?

This conference, led by Dr. Clare Harrop shares the latest research tracing the developmental pathways of autistic girls and women, from early childhood through to adulthood. As autism diagnoses in females rise and the gender gap continues to narrow, understanding their distinct profiles and experiences has never been more important. Dr Harrop explores current evidence on diagnostic patterns, the phenomenon of late diagnosis, and life experiences that may be uniquely female, highlighting the critical gaps that still remain. Essential for professionals interested in a deeper, more inclusive understanding of autism across the lifespan.

References

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Harrop, C., Tomaszewski, B., Putnam, O., Klein, C., Lamarche, E., & Klinger, L. (2024). Are the diagnostic rates of autistic females increasing? An examination of state-wide trends. Journal of Child Psychology and Psychiatry, 65(7), 973–983. https://doi.org/10.1111/jcpp.13939
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