Up to 600 more people could be undiagnosed autistic in Ceredigion, the region’s health board fears – with waiting lists for diagnosis as long as three and a half years.

Hywel Dda University Health Board, which oversees healthcare in west Wales, has set itself the target of improving waiting times for assessments.

A report that went before Ceredigion County Council earlier this month estimates that one in every 100 people in a population will have a diagnosis of autism.

This would mean that there are in the region of 750 autistic people in Ceredigion. But figures from 2020-21 show there are only 150 people diagnosed in the county.

The health board told the Cambrian News there are currently 145 children in the county (and 2,270 under Hywel Dda’s jurisdiction) waiting for an autism diagnosis.

The average waiting time for children seeking assessment is 182 weeks.

There are 306 adults on the waiting list and it can take as long as 190 weeks to get an appointment.

A health board spokesperson said: “Hywel Dda University Health Board is committed to improving neurodevelopmental services, in recognition of the increasing demand for assessment.

“Systems are in place to ensure that where necessary, children and adults will be expedited if clinical or social/emotional need dictates.

“We are undertaking waiting list initiatives in order to reduce the waiting times.”

The report and the figures have sparked fears that many hundreds could be without the support they need from health and education authorities.

The report compiled by the West Wales Care Partnership entitled Population Needs Assessment said: “Autism is a developmental disorder which affects the way a person communicates with and relates to other people and the world around them.

“The way in which people are affected varies from one individual to another and by age and intellectual functioning.

“Estimates of the prevalence of autism spectrum disorders suggest rates of around 1 per cent in the general population, but there is much debate and the suggestion that not all individuals are identified.

“New services for adult diagnosis have been set up across Wales at a time of rising awareness of the spectrum of autism experiences; however, until recently no studies have examined adult autism prevalence in Wales.

“Increased rates of diagnosis and more prevalent autism in the community necessitate increased funding for specialist services to enable autistic adults to receive any support they require.

“Estimates are likely to be underplaying the true prevalence rates in West Wales.”