Why Autism Isn’t Diagnosed in Girls and Women
In recognition of April’s Autism Acceptance Month, we invited BHI Core member Dr. Wayne Fisher to share his perspective on a recent CNN Health article, “Why autism isn’t diagnosed in girls and women”. The article explores growing concerns around the underdiagnosis and misdiagnosis of autism in females—a topic that has sparked increased attention among clinicians and researchers. Dr. Fisher offers an insightful commentary on the scientific findings and implications for both clinical care and future research.
Autism is defined by deficits in social communication and repetitive activities, interests, or behavior. Researchers have historically reported that autism is four times more common in males than females, but more recently, researchers have questioned whether this male-to-female ratio is inflated and whether females with autism are more likely to be misdiagnosed or underdiagnosed relative to males. Professor Gina Rippon has been a leading voice advocating for increased research on females with autism.
Researchers have questioned the reported four-to-one ratio of males to females in autism in part because (a) females diagnosed with autism tend to be identified at a later age than their male peers (Giarelli et al., 2010) and (b) population-based studies that systematically screen all individuals in a defined population tend to find lower male-to-female ratios (M = 3.25) than those that only include participants with a pre-existing clinical diagnosis of autism (M = 4.56; Loomes et al., 2017). Hypotheses regarding the underdiagnosis of females with autism include (a) females may be genetically protected from autism (requiring a greater genetic load than males to produce equivalent symptoms; Hull et al., 2020); (b) females with autism tend to better hide or camouflage their autistic symptoms relative to their male counterparts (e.g., inhibiting repetitive movements, using more gestures; Rynkiewicz et al., 2016); and (c) females with autism may present with a phenotype that differs from males, and the symptoms that are unique to females may not receive sufficient weight because the diagnostic criteria for autism were developed primarily based on males with autism (Hull et al., 2020; Rippon, 2024).
Under and later diagnosis of females with autism has at least two important negative consequences. First, they can result in delayed or denied access to effective intervention. Second, females tend to be underrepresented in autism research, which inhibits progress toward understanding aspects of autism that are unique to females, which in turn may perpetuate the underdiagnosis of females with autism. As such, clinicians should take these findings into consideration when assessing and diagnosing females for autism, and they should pay close attention to the possibility that females may hide or camouflage their autistic symptoms. In addition, for certain research questions, investigators should consider studying female individuals with autism separately from males and including near-equal numbers of males and females so that important sex differences can be assessed and identified.
References
Giarelli, E., Wiggins, L. D., Rice, C. E., Levy, S. E., Kirby, R. S., Pinto-Martin, J., & Mandell, D. (2010). Sex differences in the evaluation and diagnosis of autism spectrum disorders among children. Disability and Health Journal, 3(2), 107-116. https://doi.org/10.1016/j.dhjo.2009.07.001
Hull, L., Petrides, K. V., & Mandy, W. (2020). The female autism phenotype and camouflaging: A narrative review. Review Journal of Autism and Developmental Disorders, 7, 306-317. https://doi.org/10.1007/s40489-020-00197-9
Loomes, R., Hull, L., & Mandy, W. P. L. (2017). What is the male-to-female ratio in autism spectrum disorder? A systematic review and meta-analysis. Journal of the American Academy of Child & Adolescent Psychiatry, 56(6), 466-474. https://doi.org/10.1016/j.jaac.2017.03.013
Rippon, G. (2024). Differently different?: A commentary on the emerging social cognitive neuroscience of female autism. Biology of Sex Differences, 15:49, 1-16. https://doi.org/10.1186/s13293-024-00621-3
Rynkiewicz, A., Schuller, B., Marchi, E., Piana, S., Camurri, A., Lassalle, A.,& Baron-Cohen, S. (2016). An investigation of the ‘female camouflage effect’ in autism using a computerized ADOS-2 and a test of sex/gender differences. Molecular Autism, 7(10), 1-8. https://doi.org/10.1186/s13229-016-0073-0
Wayne W. Fisher, PhD, BCBA-D
Henry Rutgers Endowed Professor of Pediatrics, Robert Wood Johnson Medical School (RWJMS)
Director of Rutgers Center for Autism Research, Education and Services (RUCARES) in the BHI
Chair of BHI Neurodevelopment Focus Area Working Group (FAWG)
