The definition of autism may have become so broad that it risks confusion and possible misdiagnosis, according to an editorial by University College London Professor Dame Uta Frith published on Aug. 3.
Frith, whose research in the 1960s and 1970s helped establish the foundations for understanding autism, said in Psychological Medicine that the current use of Autism Spectrum Disorder (ASD) as a single condition now includes a wide range of people—from those needing round-the-clock care to those who live independently. "Autism wasn't always defined this way – a sort of catch-all diagnosis for a huge variety of conditions," she said.
She explained that when autism was first identified in the 1940s, it referred to children with severe difficulties in social interaction, communication, and behavior. Over time, she said the definition has widened to include people with milder traits and no language or learning problems. "Today, anyone of any age or intelligence level can be diagnosed with autism if they meet certain criteria," Frith said.
Frith noted that diagnoses have increased dramatically over time: from about four in 10,000 children in the UK during the 1960s to around one in 57 schoolchildren today—a more than fortyfold increase. She suggested several reasons for this rise but emphasized concerns about overdiagnosis: "This matters because diagnoses shape treatment, identity, and support. A wrong diagnosis can lead to the wrong help, or no help at all," she said.
Her editorial also highlighted differences between individuals diagnosed as children versus those diagnosed later as teenagers or adults. Some studies suggest these groups may even have different genetic patterns. Frith warned that expanding definitions could result in people being labeled autistic when another condition might better explain their difficulties.
Frith addressed how cultural factors influence perceptions of autism: "Autism is no longer just a medical term - it has become part of popular culture. Social media, films, and online communities have helped people share experiences but they have also spread simplified or misleading ideas." She added that while concepts like neurodiversity reduce stigma by framing autism as a difference rather than a disorder, this raises questions about why medical diagnoses are used if it is not considered a disorder.
In her conclusion, Frith called for reconsideration of how autism is defined and diagnosed: "The time has come to examine whether the autism spectrum has become too broad. Without greater precision we risk misunderstanding people's needs and misdirecting care."
