New research finds strong gender differences in autism

Posted 1 year ago by David McManus
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Image caption: Research suggests that boys are, on average, four times more likely to have autism than girls. (Source: Shutterstock)
Image caption: Research suggests that boys are, on average, four times more likely to have autism than girls. (Source: Shutterstock)

New research reveals that under-detection of ASD in girls may be partly driven by differences in how symptoms appear across genders. In addition, clinicians may have a limited idea of how people express ASD symptoms, based on male detection models.

Key points:

  • Girls with autism spectrum disorders (ASD) tend to be diagnosed later than boys, largely because they can present with different characteristics than those classically related to ASD.
  • However, this may hide the true incidence of autism in girls and women, with some estimates ranging from 7:1 to as low as 2:1 (that is, two boys for every girl with autism). This means that they may not receive the support they need.
  • Autism in girls may lead to: a tendency to impersonate others in social situations to blend in, melting down in private, strong sensory feelings relating to sound and touch.

“Tools currently being used to measure ASD (Autism Spectrum Disorder) traits are based on research based on male participants, meaning that they are not sensitive to how girls present,” says lead researcher Dr Joanna Tsirgiotis, from the College of Education, Psychology and Social Work at Flinders University.

“We need to better understand the unique challenges of girls so that we can improve our diagnostic assessment processes, ensuring they are appropriate for them.”

Dr Tsirgiotis says the research highlights that women with ASD may have less obscure niche interests and fewer repetitive behaviours, and are often highly socially motivated and eager for friendships, unlike what is often assumed about children with autism. Essentially, they’re less introverted, which is a strong indicator for ASD in males, particularly for spectrum disorders such as Asperger’s syndrome.

“This is important because without a diagnosis, they likely will not receive the support that they may need,” says Dr Tsirgiotis.

Researchers analysed profiles of 777 children using two commonly used diagnostic tools measuring ASD traits. This provided insight into how ASD presentations may differ between diagnosed male and female children.

They found that differences between boys and girls identified in this study, both in symptom type and severity, may be less noticeable in girls to referrers, such as parents and teachers, and clinicians tasked with assessment.

“Girls tend to engage in less obviously neurodivergent behaviour and this can add murkiness to the diagnostic picture. If we don’t have a clear idea of ASD in girls, their characteristics can be misinterpreted as anxiety, quirkiness or even as ‘normal’ behaviour,” says Dr Tsirgiotis.

In another study, the Flinders University researchers looked at clinical judgement and decision making, finding that diagnosticians may be much less confident in autism assessment for girls – and they interpret ASD behaviours differently depending on the child’s sex.

“Diagnosticians find it harder to assess girls because their difficulties are often more subtle in social environments, and they lack trust in our current assessment tools and criteria which are less than ideal in reflecting girls’ experience of ASD,” says Dr Tsirgiotis.

The researchers suggest that timely ASD diagnosis requires greater understanding of the unique challenges faced by autistic girls, and that assessing practitioners are aware of more subtle or alternate expressions of neurodiversity, adapting their assessment to what we are learning about autism in girls.

“In these studies, we identified several areas in which females may be more likely to present as typically developing, which may further compound under-detection and mean that the broader constellation of ASD difficulties is overlooked,” says Flinders University’s Professor Robyn Young, a co-author of the research.

“It is therefore critical that diagnosticians, referring clinicians and teachers are educated in these differences so that females’ ASD may be detected in a timely manner.”

The Disability Support Guide to the role gender plays in ASD symptoms and diagnoses expands upon some of the established things to look for in assessment and managing autism.