'I wish superstars Lewis and Billie would talk more about Tourette's'

John Davidson introduced Tourette's to many people

The man who inspired an upcoming movie about Tourette's syndrome has called on music superstars Lewis Capaldi and Billie Eilish to talk more about their experience with the condition.

John Davidson was the person who introduced Tourette's to many people, through a series of documentaries, beginning with John's Not Mad in 1989.

Then 16, he embodied the condition once described as "wild madness", which caused him to spasm and jerk, swear uncontrollably and shout explicit sexual phrases.

John, now 54, thinks it's time for fellow sufferers Capaldi and Eilish to take on the mantle of public awareness.

Lewis Capaldi returned to the Pyramid Stage at Glastonbury in June for the first time after a break following his Tourette's diagnosis

John, from Galashiels in the Scottish Borders, told BBC Scotland's Scotcast podcast that he was "humbled" to share something in common with the superstars but felt they had more to offer.

He said: "They are on a huge platform and I just wish they were able to talk more about their condition and how it affects them - give that extra little push, because they're out there in the public eye constantly.

"They didn't choose to have Tourette's, but they choose that life so they really need to be able to feel confident that their fans understand them and they're willing to accept that this is who Lewis is, this is who Billy Eilish is, and for me this is who John is.

"We need to normalise people who are neurodivergent, Tourette's, autism, ADHD," he said.

Billie Eilish has spoken about tics and living with Tourette's and how it can be "exhausting"

John added that seeing Capaldi entertain a crowd at Glastonbury was inspiring.

"I'm pretty positive that Lewis is proud. Nobody wants to have Tourette's but I'm sure he feels very proud that he is somebody who can entertain a crowd of 100,000 people having this condition that once upon a time was frowned upon and people were shut away.

"He's able to stand up there with confidence with the knowledge that people are beginning to understand and there's a difference between really understanding the condition and knowing what Tourette's is."

John has chosen to keep the spotlight on himself for more than 30 years to highlight the condition which - according to NHS statistics - affects around one in a hundred school-aged children in the UK.

His story is being told in the new film I Swear.

The film, which stars Scots actor Peter Mullen, charts John's heartbreaking journey to understanding his condition.

John said: "It was devastating. I didn't know what was going on. I was scared and I just wanted to hide all the time .

"It could destroy a person and it nearly did destroy me on two or three occasions.

"All I wanted was for people to understand and to listen to me and believe that, you know, I'm doing all this kind of strange behaviour and the tics and stuff. I can't control it. When you're a youngster all you want is to be the same as your mates the same as your peer group but when I was young I couldn't - I'd lost all that in my childhood."

John Davidson featured in the BBC documentary John's Not Mad in 1989

What is Tourette's syndrome?

TS is neurological condition that causes a person to make involuntary sounds and movements called tics.

It usually starts during childhood, but symptoms normally improve after several years and sometimes go away completely.

Tics can be brought on by anything at all but stress and anxiety are common triggers.

Most people with TS are not significantly affected by their tics or behaviours, and so do not need medication. However, there are options available which can help control the tics if they are causing problems.

Sources: NHS and Tourette's Action

John says a lot has changed since he first brought attention to the condition and life has improved for those who have it.

"I think they are getting treated a lot better. They are more understood in schools and clubs, football, sports clubs and stuff but there's still a long way to go into fully understanding the condition," he said.

"I've worked with young people for the best part of 30-odd years and watching these young people grow up with confidence, proud of the knowledge that we're living in a more understanding society. But like everything else there's still a long way to go."

He says the best thing for people to do is "completely ignore" the tics, even though he says "sometimes hilariously funny ticks come just at the right time".

John added: "I laugh all the time about some of the things I come out with and some of the movements I have and stuff. You know if you didn't laugh you would cry."