Researchers have called for better support for middle-aged and older autistic people after a review found that 90% of autistic people aged over 50 in Britain are either undiagnosed or misdiagnosed.Greater awareness of autism and improved assessments globally mean it is typically spotted in childhood today.But in past decades autistic people were often forced to navigate middle and old age without the support a diagnosis can unlock.The review into ageing across the autism spectrum found that people in the UK faced widespread difficulties with employment, relationships and milestone events such as menopause and retirement.They consistently suffered from poorer mental and physical health.

“Autistic children grow into autistic adults and we know that they are more likely to have higher rates of most physical and mental health problems,” said Dr Gavin Stewart, co-lead of the Re:Spect Lab at King’s College London and lead author of the review.“People often need a diagnosis, or need to recognise it within themselves, to be able to ask for appropriate help and support.”As part of the review, Stewart and Prof Francesca Happé, also at King’s, re-analysed UK healthcare records from 2018.By comparing rates of autism in middle-aged and older people with the 1% national prevalence recognised today, they estimate that in the UK 89% of autistic people aged 40 to 59, and 97% of those aged 60 and over, are undiagnosed.While global autism rates have risen in recent decades – in 2022, one in every 31 Americans under the age of eight were found to have the condition – the trend is largely attributed to a broadening of the definition and improvements in diagnoses, rather than a genuine increase in the percentage of people affected.

The researchers went on to examine how autistic and non-autistic people fared throughout life.The former had higher rates of a multitude of conditions ranging from anxiety and depression to cardiovascular disease and neurological disorders, they found.Among the most troubling findings were higher rates of suicidal thoughts and self-harm in older autistic people, and a greater risk of early onset dementia.Average life expectancy differed by six years, with autistic people living to 75 years old, compared with 81 years old for non-autistic people, but these figures could be skewed by the poor diagnosis rates.Details are published in the Annual Review of Developmental Psychology.

“We need to understand how ageing impacts autistic people to better understand what sort of tailored help and support they would actually benefit from,” Stewart said.“These are all things that the [autism] community needs to be consulted on.”Autism varies from person to person, but doctors look for core characteristics when assessing people.These include differences in social communication and rigid and repetitive behaviours.The differences in communication can lead people to become socially isolated.

This, alongside the stigmatisation that many autistic people face, can raise the risk of mental and physical health problems.It can also make it harder for autistic people to find people to approach for help and support.According to the review, older autistic people were more likely to face challenges in coping with major life events such as arranging residential care.“If you are going from working nine to five all of your working life to suddenly not, that could have a real impact on you,” Stewart said.“And if you’re going into a care home where you’re suddenly forced into situations that you wouldn’t typically experience in your own home, that has a big impact.

”He added: “If an autistic person is having more difficulties throughout their life, when they reach these points they can be real breaking points.That’s where support would be really beneficial.”Tim Nicholls, at the National Autistic Society, said: “This research clearly shows what we already know and hear about every day – there are high numbers of undiagnosed autistic adults and going through life without a diagnosis has a major impact on many aspects of their lives.“Autism assessments can be the first step to understanding people’s needs and a diagnosis can be life changing and, in some cases, lifesaving.Autistic people and their families face a constant fight for support and far too often this starts with long waits for a diagnosis.

“The government must provide urgent funding for diagnosis services and make sure autistic people and families get the support they need when they need it.” In the UK and Ireland, Samaritans can be contacted on freephone 116 123, or email jo@samaritans.org or jo@samaritans.ie.In the US, you can call or text the 988 Suicide & Crisis Lifeline at 988 or chat at 988lifeline.

org.In Australia, the crisis support service Lifeline is 13 11 14.Other international helplines can be found at befrienders.org