Autism screening tool may not pick up women with the condition

May 23, 2018 by Rachel Moseley And Julie Kirkby, The Conversation
Credit: Nikodash/Shutterstock.com

Diagnosing autism is expensive and time consuming, so a screening tool is used to filter out those people who are unlikely to be diagnosed as autistic. This is all well and good, but our latest research suggests that a widely used screening tool may be biased towards diagnosing more men than women.

Earlier studies have cast doubt on the ability of one of the leading tools, called Autism-Spectrum Quotient, to accurately identify people with . Our study decided to look at another that hasn't yet been investigated: the Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R), a widely used questionnaire for assessing autism in adults with average or above average intelligence.

We compiled the RAADS-R scores of over 200 people who had a formal diagnosis of autism. We compared scores between autistic men and autistic on four different areas: difficulties with social relationships, difficulties with language, unusual sensory experiences or motor problems, and "circumscribed interests" (a tendency to have very strong, fixed interests).

As there are known sex differences in these areas – for example, with women being better at hiding social and communicative difficulties, and men being more likely to show obvious, and hence easier to detect, circumscribed interests – we wanted to know whether RAADS-R was able to pick up these differences.

Our analysis showed that it didn't: we found no sex differences in RAADS-R scores between autistic men and women in social relatedness, language and circumscribed interests.

A possible explanation for this result is that, since RAADS-R depends on people accurately judging and reporting their own symptoms, sex differences may only emerge when behaviour is diagnosed by an experienced clinician. Previous studies have shown that autistic people often lack insight into their own behaviour and find it difficult to report their own symptoms.

Another likely reason for finding no sex difference in autism traits is that this and most other studies only include autistic people who have received a formal diagnosis through assessment with the very tools and tests we are investigating. As diagnostic and screening tools (including RAADS-R) were developed with male samples, they are most likely to identify autistic women with the most male-like profiles.

Some autistic people are sensitive to certain fabrics. Credit: Purino/Shutterstock.com

This might explain why fewer women tend to be diagnosed. It could be, then, that the screening tests filter out all of the autistic women with more female-like autism traits, and the autistic women with more male-like traits go on to be diagnosed. Or it could be that the underlying sample is biased because the formal diagnostic tools select people with more male-like traits, and the screening merely reflects this underlying bias.

Our results could show that our sample didn't represent a diverse range of autistic women, then. And this is a problem that affects all research on in autism.

As more males than females have received a diagnosis of autism, many of the theories we have about autism are based on these diagnosed cases, and, as a result, may only apply to males. Likewise, as we base our screening tools and diagnostic tools on males who have been diagnosed, we may only pick up women who show male-like symptoms.

We could be missing the women who have very different, more female presentations of autism, but who still show the core features that are central to the diagnosis. These include problems with social interaction, communication and restricted behaviour and interests.

Because screening and diagnostic tests focus on the most common, male manifestations of these core symptoms, females tend to be overlooked. Circumscribed interests in males, for example, are more likely to be based on unusual topics, whereas girls and women may centre their interests on things like celebrities or fashion, only the intensity of the interest sets them apart from non-autistic females.

One clear difference

There was only one prominent sex difference that emerged in our study: autistic women reported more sensory differences and motor problems than autistic men. Sensory and motor symptoms are common in autism. People may be over or under sensitive to sights, sounds, touches, smells and tastes, and are often clumsy and poorly coordinated.

This self-reported finding, that women have more sensory and motor symptoms than men, needs to be investigated more thoroughly. However, it appears to be consistent with a few studies that have found that autistic women do have more sensory and motor symptoms than men.

If these types of symptoms are especially problematic for autistic women, they could be important for providing a diagnosis. Although RAADS-R measures sensory and , they play a very minor role in gold-standard diagnostic tests, such as the Autism Diagnostic Observation Schedule.

The importance of a diagnosis?

Efforts are now underway to develop screening tools that are better at identifying autism in females.

Diagnosis is important for autistic people for many reasons. For example, it is the only way they can access support services, such as dedicated support workers to help them with activities at home or in daily life. They might also receive financial support if they need it. (Unemployment affects most of the autistic population and may in part be due to high levels of mental illness in this group.)

Other people have spoken about how having a diagnosis has helped them understand the struggles they've faced in their lives – that these things weren't their fault. And it has helped them meet other people who accept them for who they are.

Explore further: Better tools needed to diagnose depression in people with autism

Related Stories

Better tools needed to diagnose depression in people with autism

February 16, 2018
Autistic adults are not being effectively diagnosed with depression due to a lack of asessment tools, a new study has found.

Research reveals autism and schizophrenia share common traits

April 24, 2018
New research at Swinburne has revealed a significant overlap in the traits associated with autism and schizophrenia.

Autism is not linked to eating fish in pregnacy

May 21, 2018
A major study examining the fish-eating habits of pregnant women has found that they are not linked to autism or autistic traits in their children.

Girls' social camouflage skills may delay or prevent autism diagnosis

January 4, 2018
On parent-reporting measures, girls with autism seem to struggle more than boys with performing routine tasks like getting up and dressed or making small talk, even when the study group is normalized to meet similar basic ...

How coping mechanisms help autistic people

October 24, 2017
In a recent documentary, naturalist and wildlife presenter, Chris Packham, talked about having Asperger's Syndrome, a form of autism. It was a rare snapshot into the life of an adult with Asperger's – and especially so ...

Masculine features linked to autism

September 26, 2017
We can now log on to our iPhones using 3-D facial scanning, but 3-D scanning also has some very vital medical benefits.

Recommended for you

Tackling bullying could help reduce depression in autistic teens

June 19, 2018
Teenagers with difficulties in social communication, including autism have higher rates of depressive symptoms, especially if they are being bullied.

Link found between neurotransmitter imbalance, brain connectivity in those with autism

June 6, 2018
One in 59 children in the United States lives with a form of autism spectrum disorder, according to the Centers for Disease Control and Prevention. The signs of autism begin in early childhood and can affect individuals differently. ...

Mobile app for autism screening yields useful data

June 1, 2018
A Duke study of an iPhone app to screen young children for signs of autism has found that the app is easy to use, welcomed by caregivers and good at producing reliable scientific data.

Baby teeth give clues to autism's origins, detection

May 30, 2018
A close examination of baby teeth is giving new insight into the roots of autism—and ways to spot it early.

Screening may miss signs of autism, especially in girls: study

May 21, 2018
(HealthDay)—An important checklist used to screen for autism can miss subtle clues in some children, delaying their eventual diagnosis.

Scientists just beginning to understand autistic adults' unique health needs

May 11, 2018
In the 1990s, the prevalence of autism spectrum disorder (ASD) among children rose sharply. These children are now entering adulthood, yet physicians and scientists know very little about the health outcomes they might face. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.