He has to sit in the back of a car, with the seatbelt wrapped around his hands, because he would try to grab the steering wheel or assault the driver.Shame"I'm fighting against really bizarre thoughts that come into my head, sometimes quite visual things that are going to happen and I go through them in my mind and it creates panic attacks and anxiety attacks.Twenty years ago, John Davidson became the face of Tourette Syndrome, when a BBC documentary about his daily battles with the illness became a national talking point.
"I don't like upsetting people, I don't like offending people and that [embarrassment] is never going to go away because that's the kind of person I am." He still faces ridicule and his favoured response is to strike up conversation and try to explain his condition.
People who find his outbursts funny don't realise how hard these tics make his life, he says.
Viewers of the documentary saw how his uncontrollable foul-mouthed outbursts and violent body jerks denied him a normal life.
Some people in his hometown of Galashiels crossed the road to avoid him and told their children not to play with him.
It's a life he enjoys, with close friends and relatives living nearby, and as well as his Tourette campaigning, he does a lot of voluntary youth work.