In the last decade, the global prevalence of autism has almost doubled, reflecting the major improvements in public awareness and understanding of autism spectrum disorders (ASD). Children and Adults are now more likely to be diagnosed, increasing their understanding of themselves and improving their quality of life.

While this has been an amazing achievement, researchers noticed a skewed prevalence in favour of male diagnoses of ASD, with a 4 to 5:1 male-to-female ratio. Why are more men diagnosed as autistic than women? This question must be addressed to relieve women of the burden of not understanding their ASD-related challenges, their struggles with treatment, and the impact these lower identification rates have on their quality of life.

It’s essential to understand the ‘why’ before we can address how to make change. Researchers are currently exploring the sex and gender differences in autism and have suggested different explanations, from biological to sociocultural based differences between the sexes, and are investigating more effective diagnosis methods. In this article, we delve into the latest research and findings, and examine the issues that can arise due to undiagnosed autism in women.

Is the diagnostic criteria tailored towards men?

Since the initial clinical definition of autism, autism has been more prevalent in males than females. A look into this research revealed a largely skewed sample of participants, with more males than females. This suggests that the criteria and tools used today to diagnose ASD are based on research that is under-representing women, making them more geared towards a male bias of ASD symptoms.

Interestingly, research that looked at ASD cases, regardless of a clinical diagnosis, found lower male-to-female ratios of 3:1 or 2.5:1.5. One explanation for this is that there are women who would be diagnosed with ASD if evaluated, but they are being missed due to male bias in the diagnostic criteria and their unique clinical presentations.

Is there a biological explanation for sex-differences in autism?

Researchers have explored several biological based theories on sex-differences in autism, surrounding genetic factors, prenatal hormone exposures, and brain structure differences.

One theory is The Extreme Male Brain theory (EBM). This theory expands on the empathising-systemising theory (E-S) of typical sex differences. The E-S theory suggests that women typically have a drive to empathise with people and their needs, while men have a stronger drive to systemise and build rule-based systems.

The EMB theory explains that people with ASD take on an extreme profile of the typical E-S dimension male, and have a more masculine brain type. Therefore, men would need smaller psychological and physiologic changes to present with ASD than women, making them easier to detect.

While this theory has several points of evidence, it also has its criticisms.

Are ASD women better at social communication?

Research has shown that women with autism can have different clinical presentations that could be more subtle, allowing better social communications, and less intense restrictive and repetitive behaviours. Why is this?

Women are exposed to social and cultural influences from a young age that impact their expression of ASD symptoms. Unlike ASD children with significant developmental delays, those without delays go unnoticed and are raised under the same social norms and expectations as other children. When we are raising girls, we tend to use more social language and discuss emotions more than with boys. We also teach girls more interactive and imaginative play than boys (e.g, kitchen sets and dolls). So, from a young age, women are taught how to be better at social communication which deviates them from “classic” autism symptoms.

This change, however, does not always come naturally to women with ASD, and could impact their mental health as they grow. This is because social demands increase, especially for women, through adolescence and adulthood, outweighing the social support they receive inchildhood.

While male friendships are typically centredaround liking the same activities (e.g, attending sports games, video games), female friendships typically centre around emotional support, and exchanging personal information, requiring a higher-level of social skill. This makes maintaining female relationships much harder for ASD women and has been reported to cause feelings of “otherness.”

To avoid rejection, and to connect with their peers, research has shown that people with ASD tend to use masking techniques to hide features of ASD in social situations. The increased social demands placed on women may explain the increased use of masking in women compared to men. They imitate body-language, speech patterns and suppress their ASD symptoms. Maskingcan be incredibly exhausting and has been associated with higher self-reported symptoms of generalisedanxiety, social anxiety, and depression in men and women.

Research findings on Social Communication sex-differences

Sturrock et al., (2020) found that women with ASD did present deficits in social communication skills, when compared to typical women, but they outperformed men with ASD, and even typical men on some skills such as emotional vocabulary. This suggests there may be some skills preserved by sex.

Cola et al., (2022) found that word choices influence diagnostic assessment. Girls use more “socially-focused” words which corresponded to greater ratings of social communication skills, despite being matched for autism severity with the boys.

Do ASD women have less intense restrictive repetitive behaviours (RRBs)?

RRBs include repetitive motor movements and intense interests in typical or atypical topics (e.g, numbers, flags). Many researchers have stated that ASD women simply have less intense circumscribed interests than ASD men, however, this may not be the case.

Some have suggested that the specific topics of interests vary by sex. ASD women have been reported to have more random circumscribed interests that are not traditionally associated with autism. Other reports propose that women have intense interests in topics that are more in line with their peers and are so considered positive interactions.

How do we move forward?

While the diagnostic criteria may be biased to male ASD expressions, researchers are finding autism symptoms unique to women. For example, while women are more skilled in social situations, they have more difficulty maintaining relationships. Women may also have unique RRBs.

We need to acknowledge that, because of their tendency to be good at masking, and the different sociocultural influences on their development, ASD women do not always fit the autism stereotype.

Since primary ASD research under-represents women, there is a need in to explore female specific symptoms of ASD and broaden the diagnostic criteria to relieve women of the pressures of their ASD-related challenges, and better their mental health.

References

Ochoa-Lubinoff, C., Makol, B. A., & Dillon, E. F. (2023). Autism in women. Neurologic Clinics, 41(2), 381-397. https://doi.org/10.1016/j.ncl.2022.10.006