Autism Spectrum Disorder, or ASD, is a neurodevelopmental condition that represents with a variety of clinical characteristics. Some signs could be weaknesses in social skills and communication, restricted interests, repetitive behaviors, etc. The CDC estimates that 1 in every 54 US children has autism. However, not all children, adolescents or adults are diagnosed equally. The male-to-female ratio for ASD diagnoses in the US is widely reported as 4:1 (Green et al., 2019). The disparity widens as intelligence increases, suggesting that females with higher cognitive and language abilities tend to receive diagnoses later or go unidentified completely (Jamison et al., 2017). This ratio is likely a misrepresentation of the true prevalence of ASD across gender, a complex issue underpinned by a number of contributing factors.
The diagnostic gap is, in part, caused by bias towards the detection of male symptoms in existing diagnostic techniques. Meta-analysis studies on how clinicians diagnose ASD show that female patients, on average, have less restricted and repetitive behaviors and interests. These gender discrepancies have created a body of data with drastically greater male representation than female representation, upon which further analysis is performed, perpetuating the diagnostic gap.
There are also differences in the presentation of ASD in male and female persons, observed throughout the lifespan. Childhood and adolescence are two highly sensitive periods for the detection of ASD and are also where these differences in presentation are most observed (Jamison et al., 2017). A 2014 study on the “female phenotype” of ASD found that, beginning in childhood, the speech of females contains more vocabulary words related to emotions when compared to males. Females with ASD are also reported to have restricted interests related to people and animals instead of inanimate objects, common in males (Green et al., 2019). In adolescence, there is a notable gender divergence in the psychiatric comorbidities reported in individuals with ASD. Compared to females, males show heightened rates of externalizing disorders, including possible oppositional tendencies, hyperactivity, and inattention. After the age of 15, females with ASD have “exceptionally high risk” of developing depression and experience elevated rates of internalizing disorders, like anxiety and eating disorders, compared to adolescent males with ASD (Green et al., 2019). On average, females are diagnosed later in life than males. This can mean a lifetime of feeling misunderstood, possibly contributing to this observed pattern.
It is also important to consider the contributions that social constructions of gender make in the diagnostic gap in ASD. Stereotypes and socialization play a role in how parents, educators, and clinicians interpret certain behaviors and recognize them as symptoms of AS
As these factors are identified and discussed in ASD literature, progress is being made to close the diagnostic gap. Recent studies show a trend towards a lower gender ratio and a dissociation of gender from intellectual disability, which suggests that improvements are being made in identifying high-functioning females (Lai et al., 2015). With sensitivity to the differences between male and female presentations, ASD research should focus on identifying all persons on the spectrum and to identify each person’s strength/weakness and grow to be more inclusive in the future.
If you have any questions, please call our office.
Steven P. Greco, PhD, ABN
Board Certified, Neuropsychology
References:
Green, R. M., Travers, A. M., Howe, Y. & McDougle, C. (2019). Women and autism spectrum disorder: Diagnosis and implications for treatment of adolescents and adults. Current Psychiatry Reports, 22, 1-8. DOI: 10.1007/s11920-019-1006-3
Jamison, R., Bishop, S. L., Huerta, M. & Halladay, A. K. (2017). The clinician perspective on sex differences in autism spectrum disorders. Autism, 21(6), 772-784. DOI: 10.1177/1362361216681481
Lai, M., Lombardo, M. V., Auyeung, B., Chakrabarti, B. & Baron-Cohen, S. (2015). Sex/gender differences and autism: Setting the scene for future research. Journal of the American Academy of Child & Adolescent Psychiatry, 54(1), 11-24. DOI: 10.1016/j.jaac.2014.10.003