What’s the difference between autism and Asperger’s disorder?

Swedish climate activist Greta Thunberg describes herself as having Asperger’s while others on the autism spectrum, such as Australian comedian Hannah Gatsby, describe themselves as “autistic”. But what’s the difference?

Today, the previous diagnoses of “Asperger’s disorder” and “autistic disorder” both fall within the diagnosis of autism spectrum disorder, or ASD.

Autism describes a “neurotype” – a person’s thinking and information-processing style. Autism is one of the forms of diversity in human thinking, which comes with strengths and challenges.

When these challenges become overwhelming and impact how a person learns, plays, works or socialises, a diagnosis of autism spectrum disorder is made.

Where do the definitions come from?

The Diagnostic and Statistical Manual of Mental Disorders (DSM) outlines the criteria clinicians use to diagnose mental illnesses and behavioural disorders.

Between 1994 and 2013, autistic disorder and Asperger’s disorder were the two primary diagnoses related to autism in the fourth edition of the manual, the DSM-4.

In 2013, the DSM-5 collapsed both diagnoses into one autism spectrum disorder.

Read more: It's 25 years since we redefined autism – here's what we've learnt

How did we used to think about autism?

The two thinkers behind the DSM-4 diagnostic categories were Baltimore psychiatrist Leo Kanner and Viennese paediatrician Hans Asperger. They described the challenges faced by people who were later diagnosed with autistic disorder and Asperger’s disorder.

Kanner and Asperger observed patterns of behaviour that differed to typical thinkers in the domains of communication, social interaction and flexibility of behaviour and thinking. The variance was associated with challenges in adaptation and distress.

Between the 1940s and 1994, the majority of those diagnosed with autism also had an intellectual disability. Clinicians became focused on the accompanying intellectual disability as a necessary part of autism.

The introduction of Asperger’s disorder shifted this focus and acknowledged the diversity in autism. In the DSM-4 it superficially looked like autistic disorder and Asperger’s disorder were different things, with the Asperger’s criteria stating there could be no intellectual disability or delay in the development of speech.

Today, as a legacy of the recognition of the autism itself, the majority of people diagnosed with autism spectrum disorder – the new term from the DSM-5 – don’t a have an accompanying intellectual disability.

What changed with ‘autism spectrum disorder’?

The move to autism spectrum disorder brought the previously diagnosed autistic disorder and Asperger’s disorder under the one new diagnostic umbrella term.

It made clear that other diagnostic groups – such as intellectual disability – can co-exist with autism, but are separate things.

The other major change was acknowledging communication and social skills are intimately linked and not separable. Rather than separating “impaired communication” and “impaired social skills”, the diagnostic criteria changed to “impaired social communication”.

The introduction of the spectrum in the diagnostic term further clarified that people have varied capabilities in the flexibility of their thinking, behaviour and social communication – and this can change in response to the context the person is in.

Read more: TikTok is teaching the world about autism – but is it empowering autistic people or pigeonholing them?

Why do some people prefer the old terminology?

Some people feel the clinical label of Asperger’s allowed a much more refined understanding of autism. This included recognising the achievements and great societal contributions of people with known or presumed autism.

The contraction “Aspie” played an enormous part in the shift to positive identity formation. In the time up to the release of the DSM-5, Tony Attwood and Carol Gray, two well known thinkers in the area of autism, highlighted the strengths associated with “being Aspie” as something to be proud of. But they also raised awareness of the challenges.

What about identity-based language?

A more recent shift in language has been the reclamation of what was once viewed as a slur – “autistic”. This was a shift from person-first language to identity-based language, from “person with autism spectrum disorder” to “autistic”.

The neurodiversity rights movement describes its aim to push back against a breach of human rights resulting from the wish to cure, or fundamentally change, people with autism.

The movement uses a “social model of disability”. This views disability as arising from societies’ response to individuals and the failure to adjust to enable full participation. The inherent challenges in autism are seen as only a problem if not accommodated through reasonable adjustments.

However the social model contrasts itself against a very outdated medical or clinical model.

Current clinical thinking and practice focuses on targeted supports to reduce distress, promote thriving and enable optimum individual participation in school, work, community and social activities. It doesn’t aim to cure or fundamentally change people with autism.

A diagnosis of autism spectrum disorder signals there are challenges beyond what will be solved by adjustments alone; individual supports are also needed. So it’s important to combine the best of the social model and contemporary clinical model.

Read more: From deficits to a spectrum, thinking around autism has changed. Now there are calls for a 'profound autism' diagnosis