Why Autism Diagnoses Are Rising, and Why It’s Not About Paracetamol

Recent headlines suggesting that paracetamol causes autism have gained global attention. These claims lack scientific support, and they risk fuelling misinformation, undermining trust in healthcare, and stigmatising autistic people.

At neurobox, we offer a safe place to ask questions and to learn. We challenge misinformation with clear evidence and care, placing evidence, nuance, and lived experience at the centre of the conversation. 

These claim taps into a misunderstanding: yes, autism diagnoses have increased in recent decades. But the reasons lie in changing definitions, broader criteria, sociocultural shifts, and greater recognition, not in modern medicine. 

A landmark UK study by Ginny Russell et al. (covering 1998–2018) found that new autism diagnoses increased eight-fold over that period.[i]  This steep rise is often misinterpreted as an “autism epidemic,” but Russell and colleagues interpret it as largely a product of diagnostic change, catch-up, and shifting diagnostic practices. 

Here are key drivers of the rise: 

1. Broadening the diagnostic net and core characteristics

• Early descriptions of autism in the 1920s–1930s focused largely on male children with severe social impairment, minimal or no verbal language, and very high support needs. 

• In the 1990s, Asperger’s syndrome was added to diagnostic manuals, capturing individuals with social and repetitive-behaviour differences but fluent language and average intelligence. 

• ‘Pervasive developmental disorder – not otherwise specified’ (PDD-NOS) acted as a “safety net” diagnosis for those who didn’t neatly fit ‘classic’ autism. 

• In 2013, the DSM-5 officially retired Asperger’s as a separate diagnosis, subsuming it (and other subtypes) under the umbrella Autism Spectrum Disorder (ASD).[ii] 

• This consolidation effectively brought many who formerly had an Asperger’s or PDD-NOS label visibly into the autism criteria. 

For further information on the ‘core characteristics’ of autism needed for a diagnosis, please see: What is autism 

2. Neurodiversity movement and changing culture

• From the late 1990s onwards, the neurodiversity movement began redefining autism not as a pathology to cure, but as a form of human variation. 

• This shift encouraged self-identification, advocacy, and destigmatisation, which in turn fuelled more assessments, more diagnoses, and more recognition of people whose traits were previously marginalised. 

• In short, increased awareness leads to more diagnoses, which further expands awareness, a positive feedback loop often described as a “diagnosis loop.” 

3. Gender and adult diagnosis

• The diagnostic rise has been particularly steep among females and adults. Historically, autism was seen, even presumed to be a male experience. Many autistic girls were misdiagnosed with anxiety, OCD, or borderline personality traits, and “masked” their traits socially. 

• As clinicians better recognise gender differences in presentation, more girls and women are being correctly diagnosed.[iii]

• Among adults, the rise is dramatic: between 2000 and 2018, diagnoses in people without intellectual disability rose 787%, compared to 20% for those with intellectual disability. This suggests that many adults with subtler presentations are only now being identified. [iv]

• Individuals who would previously have been recorded under intellectual or learning disability are now categorised as autistic (sometimes in addition to Intellectual Disability).[v] 

Thus, the “rise” in autism is better framed as a rediscovery and realignment, not a sudden surge of pathology.