Society’s understanding of autism has changed — and why it matters
If you're starting to explore autism – whether for yourself, your child or someone close to you – it can help to learn how understanding of autism has evolved over time, among the medical world and society as a whole. These changes don’t just affect who receives a diagnosis, but also shape how autism is talked about, understood and supported today.
Two major diagnostic manuals have shaped the way autism is defined: the DSM (Diagnostic and Statistical Manual of Mental Disorders) and the ICD (International Classification of Diseases). Both have undergone major changes in how they identify autism, reflecting shifts in research and thinking. You can read a summary of these at the end of this blog.
Autism is now widely recognised as a neurodevelopmental condition and no longer viewed through the lens of psychosis or mental illness. Autism is a natural and valuable variation in human neurology.
The diagnostic criteria have changed significantly. This means that people who would once have been overlooked – especially women, girls, and those with less obvious traits – are now more likely to be identified.
There has been a move away from the idea that autism is something only found in childhood. Today, autism is understood as a lifelong neurotype, with traits that can become more or less visible at different points in a person’s life.
Autism is understood as a spectrum – where individual needs, strengths and challenges vary widely – rather than being split into subtypes like Asperger’s.
Embracing unique perspectives
The neurodiversity movement highlights the strengths and positive traits that can come with being autistic. These might include deep focus, creativity or a unique approach to problem-solving. Of course, there can be challenges too but this model encourages us to see the whole person, not just a list of difficulties.
By recognising the value of different ways of thinking and processing the world, the question moves from “what’s wrong?” to “what’s different?” and “what’s needed to thrive?”
A person’s environment is important
One of the most important insights in recent years is that many challenges autistic people face don’t necessarily come from autism itself, but from the world around them.
Society is largely built for neurotypical people – with expectations around communication, behaviour and sensory tolerance that can be difficult or even harmful for autistic people. This means the problem often lies not with the person, but with the lack of accommodations and understanding.
It’s a long way from being perfect but there is a better understanding now of how to make environments more inclusive.
Changing research and clinical practice
There are also changes in how autism is approached in research and healthcare. There’s growing interest in studying what contributes to quality of life for autistic people, not just reducing so-called symptoms.
Importantly, the autistic community is increasingly being included as active participants in research rather than being seen as subjects. This co-production model helps ensure that research questions are relevant and respectful, and that support services are shaped by those with lived experience.
But it’s complicated
It’s worth noting that not everyone agrees with every aspect of the shift in thinking. Some families and professionals worry that it downplays the very real challenges that some autistic people face, especially those with high support needs.
But even where there is disagreement, the conversation itself signals a growing recognition that the individual should be at the centre of decisions about how autism is described, studied and supported.
Why this matters
Understanding how autism has been defined and redefined over time isn’t just about history – it’s about recognising how those changes affect real lives today. Many people, especially adults and girls, may have grown up without knowing they were autistic, because earlier diagnostic models were too narrow to include them. Knowing that criteria have broadened and perspectives have changed can help people make sense of their own experiences, and find the support and self-understanding they may have lacked.
It can also change how we relate to others. Whether you're a parent, teacher, clinician, or simply curious, recognising autism as part of the wider fabric of humanity opens the door to more compassionate, informed and inclusive ways of engaging with everyone around us.
Summary of changes to the diagnostic criteria
DSM
DSM-I (1952) and DSM-II (1968): Autism was not recognised as a separate diagnosis and was instead viewed as a form of childhood schizophrenia.
DSM-III (1980): Introduced “Infantile Autism” as a distinct diagnosis, with narrow criteria focused on early onset (before 30 months) and a lack of social responsiveness.
DSM-III-R (1987): Broadened the diagnosis to “Autistic Disorder,” allowing for identification beyond early childhood.
DSM-IV (1994) and DSM-IV-TR (2000): Introduced the concept of Autism Spectrum Disorders (ASD), including Autistic Disorder, Asperger’s Disorder, and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS).
DSM-5 (2013): Merged all autism-related diagnoses into a single umbrella category, “Autism Spectrum Disorder,” with varying levels of support needs. Asperger’s Syndrome and other subcategories were removed.
ICD
ICD-6 (1948) to ICD-8 (1965): Autism was not yet recognised as a distinct condition.
ICD-9 (1975): Introduced “Infantile Autism” under the category of psychoses originating in childhood.
ICD-10 (1990): Recognised a broader category called “Pervasive Developmental Disorders,” which included Childhood Autism, Atypical Autism, Asperger’s Syndrome and others.
ICD-11 (2018): Aligned more closely with the DSM-5 by consolidating diagnoses under “Autism Spectrum Disorder,” with added descriptors relating to intellectual ability and language use.