What do we know about autism in women and girls?

At the end of World Autism Awareness Week, today (2 April) marks Autism Awareness Day. Stories about women and girls with ASD have been highlighted in the media over the last few years, including a recent report by the BBC, and this SPICe Spotlight blogpost takes a look at recent research about women and girls with Autism Spectrum Disorder (ASD) in Scotland.

Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a lifelong developmental condition affecting social communication, social interaction and behaviour. The term ‘spectrum disorder’ is used as people on the spectrum experience ASD in different ways and the degree of impairment varies greatly from person to person.

The use of the term ASD has replaced the use of the terms for individual conditions, such as Asperger Syndrome. Difficulties may include verbal and nonverbal communication, repetitive or very specific behaviours or interests, and sensory processing difficulties.

According to a 2012 NHS survey, 1.1% of the UK population are on the autistic spectrum. Taking this as a guide, this would mean that around 58,000 people in Scotland are thought to be on the autistic spectrum.

The Scottish Commission for Learning Disabilities publishes statistics on the number of adults with ASD known to local authorities. In 2017, it reported that 4,755 adults were identified as being on the autism spectrum. This was not broken down by gender.

Diagnosis of ASD

Diagnosis of ASD is based on a clinical assessment of a person’s behaviour along with information about their developmental history using various diagnostic criteria and screening instruments. In Scotland SIGN 145 outlines the best practice in assessment and diagnosis. This is based on the most recent diagnostic criteria for ASD.

Waiting times

Waiting times for diagnosis of ASD are highly variable across Scotland. The Scottish Government commissioned a report by the Autism ACHIEVE Alliance on this issue in 2014. The report found that the average waiting time between being referred and receiving a diagnosis was around 11 months for children. For adults, this waiting time was just over five months. Recommendations from NICE, issued in England, advise a maximum wait time from referral to assessment of around three months.

Women and autism

More men than women are diagnosed with ASD. It is thought that autism, especially in women and girls, has been historically under-diagnosed and /or misdiagnosed. Over the past 30 years, diagnosis of autism has increased by around 25%, but the number of people living with a diagnosis is not as high as the prevalence data would suggest.

Various studies have come up with a ratio of men/women with ASD from 2:1 to 16:1. In 2015, the ratio of men to women diagnosed with ASD, supported by the National Autistic Society (NAS), was approximately 3:1.

It has been generally thought that more men and boys are diagnosed with autism because boys are more likely to inherit the genetic predisposition to the condition. Although this is one explanation, recent research has suggested that other factors may influence the different rates of diagnosis. The National Autistic Society has highlighted some of these theories, including that ASD is caused by the effects of foetal testosterone on brain development leading to more autistic boys than girls.

Women and girls with ASD may present differently and this may not be picked up using the existing assessment tools. These tools were developed based on how men and boys with ASD have presented.

This may have led to under-diagnosis in women and girls. Some theorise that women and girls may be better at camouflaging or masking their difficulties, and traits of autism in girls may be underreported by teachers. This too may lead to later or missed diagnosis.  Anecdotal evidence in the media suggests that many mothers are recognising ASD symptoms in themselves after their children have been diagnosed.

The most recent SIGN guideline SIGN 145 provides information about gender differences and misdiagnosis.

Scottish Government’s Strategy

In the Scottish Strategy for Autism: outcomes and priorities 2018-2021, the Scottish Government commits to continue to support the Scottish Autism and the Scottish Women’s Autism Network (SWAN). This is to promote the Right Click Program for Women and Girls to improve the understanding by professionals and women about autism in females.

The Scottish Strategy for Autism is due to be reviewed in 2021 and an update of progress is due to be reported on in 2020.

SPICe briefings

A briefing published by SPICe in March 2017 explored Autism and provided an overview of the policies, strategies and legalisation guiding care and support for people with ASD.

Sarah Vivers (on placement with SPICe: March 2018)