All of Andrew Davies’s life he felt like he didn’t fit in, that he was somehow broken, weird or that there was something wrong with him.

That is until he discovered he was autistic at the age of 70.

“It’s just who I am and how my brain is wired … the way I experience the world is different,” he said.

Research has suggested that, like Andrew, there are many others who have spent a lifetime unaware that they are on the autistic spectrum.

Between 250,000 and 600,000 people aged over 50 in England may be autistic but undiagnosed. a study of primary care records in England he suggested.

That would mean more than 90 percent of autistic people over 50 were undiagnosed, its researchers said.

“Autism has been seen for many years as a childhood condition, but it is a lifelong condition and as people get older they remain autistic,” said Andrew.

Andrew, now 72, retired in 2019 after a long and impressive career.

He was a minister in the first 10 years of the Welsh Government and an assembly member (now known as Member of the Senedd or MoS,) for Swansea West from 1999 to 2011.

After leaving the assembly, he was chairman of the health board of Abertawe Bro Morgannwg University for six years.

Perhaps not the most obvious line of work for someone who says he “often struggled to understand and deal with other people.”

“I can be in a group and it’s keeping up with conversations, knowing what to say… it’s not knowing the rules of small talk,” said Andrew, who lives in Mount Pleasant, Swansea.

Since childhood he preferred to be alone and friends one-on-one than in groups.

This became harder to deal with in high school.

“I completely struggled,” he said.

“I felt there was something broken, something strange, something wrong.”

He found the social rules and structure of work life easier to navigate, but often felt “bombarded” and “busy” by the end of a long day.

“I guess people would have thought ‘oh, he’s quite aloof’, but it’s a combination of shyness and not knowing what to say,” he said.

Andrew is also experimenting hypersensitivity.

“I never really liked disco and rock concerts, I found the sound, for example, and the lights almost overwhelming and uncomfortable,” he said.

Other sounds, whether it was his wife chewing gum or a neighbor’s dog barking, and some smells like grease or frozen fat, as well as sights like fluorescent lights, always made him very uncomfortable.

“I just need to get away,” he said.

“You try to ignore it, but it’s a physical, visceral reaction.”

Something that has always served him well at work, which he now knows is another trait of autism – intense interests, also known as hyperfixations..

He said that he often became preoccupied with a subject he was interested in, throwing himself into intense research.

“I want to know the problem in depth, whereas most people will think ‘that’s interesting’ and move on,” he said.

He said autism research had become “another rabbit hole we’ve gone down.”

This tendency to over-engage in subjects was first identified as a possible autistic trait in itself.

He was talking to a colleague who had recently been diagnosed with autism.

The colleague said he worked with a consultant psychiatrist who took him aside and said: “I hope you don’t mind me saying this, but you have all the classic signs of autism.”

Seeing a parallel between the colleague’s detailed research and long emails and his own “penny dropped”.

Andrew started reading and listening to podcasts about autism and decided to take the online questionnaire designed by psychologist Professor Simon Baron-Cohen.

“We came out very firmly in the middle of the spectrum,” he said.

He then decided to seek a formal diagnosis, found the NHS wait was three to four years, so eventually went private.

What does having a diagnosis mean to him?

“It was just that confirmation … I wasn’t broken or weird or anything wrong, just who I am and how my brain is wired,” he said.

“When you get to this age you look back on your life, from role to soul.

“I think it helps you come to terms with the things that have happened in your life.”

Andrew has suffered from depression since he was a teenager – research suggests People with autism may be more likely to experience depression than non-autistic people, according to the National Autism Society.

He also went through periods of ill health which he now believes autistic burnout.

Figures suggest people over 50 are not being diagnosed with autism at nearly the rate of children – one in 34 children have a diagnosis of autism, compared to just 1 in 6,000 adults over 50.

“There is likely to be a very large underserved population that deserves to have the support they need,” said Dr. Gavin Stewart, a researcher at King’s College London who is interested in aging and autism spectrum disorders.

He said one of the reasons older people went undiagnosed was in the 1960s, when they were young, autism was seen as a very rare condition “whereas today it’s seen in a much more common way and prevalence rates reflect this’.

He said that for many older people receiving a diagnosis was a “lightbulb moment” and meant they could better understand their life experiences and also opened doors for help and support, for example from employers or of those providing residential care.

He would like clinicians working in older adult services to be better able to recognize undiagnosed autistic people.

“We know that people with autism often need extra help and support throughout their lives to support them with their mental health and ensure they live happy lives,” he said.

“Having the right help and support could be a real key factor in making sure they age well and I think everyone has the right to have the best life they can.”