A ‘seismic’ increase in autism awareness has pushed waiting lists to record highs, experts say.

The NHS waiting list for autism assessment is the longest since current records began five years ago.

Charities warned the lengthy waits can be damaging to patients and called for urgent action to meet the rise in demand.

Figures released by NHS Digital shows both the total number of waits for an assessment and waits longer than 13 weeks are the highest they have been since data collection started.

Last December, 172,040 people were waiting for an assessment, up from 117,020 a year earlier and more than five times the 32,220 in December 2019.

The NHS waiting list for autism assessment is the longest since current records began five years ago and charities have warned the wait is having a negative impact on patients (Stock Image)

According to the World Health Organisation, about one in 100 children across the globe has the condition (Stock Image)

Those waiting at least 13 weeks stood at 147,070, six times the number in 2019 (24,250) and up from 97,170 a year earlier.

Experts said the figures were in large part due to the growing recognition of the spectrum disorder, which was only widely diagnosed as its own condition this century.

Dr Conor Davidson, autism champion for the Royal College of Psychiatrists, said: ‘Public awareness of autism has significantly increased in recent years, and this has led to a seismic rise in the number of people coming forward for support.

‘It is estimated that at least 1 per cent of the population is autistic so it is likely demand will continue to grow in the coming years.’ He added that the ‘vast majority of people are facing unacceptable waits for an assessment, and we cannot allow this to become normal’.

Autism is a spectrum disorder which affects how people communicate and interact. According to the World Health Organisation, about one in 100 children across the globe has the condition.

Signs in adults include not understanding how others are feeling, getting anxious about social situations, having a strict routine or seeming blunt without meaning to.

Autistic children may avoid eye contact and not respond to their name being called, among other symptoms.

Autistic people are also much more likely to have a co-existing mental illness which can put them at increased risk of self-harm and suicide if they are not able to access the care and treatment they need, Dr Davidson warned.

Mel Merritt, head of policy and campaigns at the National Autistic Society, said: ‘It’s extremely worrying that waiting lists for an autism assessment in England have nearly doubled in the last year.

‘There are now more than 172,000 people potentially struggling without the right help and support in their daily lives – nearly twice the capacity of Wembley Stadium.

‘The Government promised to make significant progress in reducing diagnosis waiting times in its autism strategy, but these figures make clear how in fact the complete opposite is happening.’

A Government spokesperson said: ‘We know it’s vital to have a timely diagnosis of autism, and we’ve made £4.2 million available this year to improve care for autistic children and young people, including autism assessment services.

‘NHS England has also published a national framework to help speed up assessment, and our £13 million partnership with the Department for Education and NHS England tests ideas that will improve access to specialist support for neurodiverse children in primary schools.’