Study finds 1 in 127 people worldwide have autism, almost double the previous estimate

One in 127 people - around 61.8 million globally - are on the autism spectrum, nearly double the previous estimate, according to a new study. 

Researchers behind the new Australian study, which was peer-reviewed and published in the Lancet Psychiatry, used data from 2021 to reach the latest estimation.

These findings "underscore the importance of early detection and support to autistic young people and their caregivers globally," the study's authors wrote. 

"Work to improve the precision and global representation of our findings is required, starting with better global coverage of epidemiological data," they added.

The prevalence of autism spectrum disorder (ASD) was twice as high among men than women, the study found. 

A diagnosis gap, with girls receiving a diagnosis later or not being diagnosed at all due to different symptoms, was found to be a likely factor in the prevalence difference. 

Girls could also be more "shielded from the condition" than boys due to genetic aspects, according to the neuroscience-specialised media The Transmitter. 

The latest study, which involved 10 institutions in Australia including the University of Queensland, the University of Adelaide, and the University of Sydney, also found that ASD was most common in people under 20 years old.

During the last assessment conducted on 2019 data, the prevalence was one in 271 people or 369 per 100,000 people.

This difference is mostly explained by a method’s change, "to exclude studies that probably underestimated the rates of autism," the authors said in statement.

The most recent figure is in line with the prevalence of the World Health Organization (WHO)which estimates that one per cent of children worldwide have autism. 

Importance of an early diagnosis

Autism or Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition that manifests in early childhood and persists throughout life.

Characteristics vary among individuals but can involve difficulties in social communication and interaction, challenges related to sensory processing, repetitive behaviours, interests, or activities, and in some instances intellectual disability, all of which occur at varying levels of severity.

The signs of the condition can be visible between the ages of 1 and 3, the American Psychiatric Association said on its website. 

"Autistic people are at an increased risk of social isolation, academic or employment difficulties, and might require psychosocial support into adulthood," the study authors said, adding that an early diagnosis can improve the outcome.