John Davidson has been the poster boy for Tourette syndrome since 1988, when a documentary about him called ‘John’s Not Mad’ aired on BBC One. It showed the then 16-year-old from the Scottish Borders, living with explosive, often sweary tics, in a world that didn’t understand the condition.

Three decades on, we’re much more aware of Tourette syndrome and that’s in no small part down to John and his campaigning. Now, a film based on his life - ‘I Swear’ - starring Maxine Peake and Robert Aramayo is about to be released.

In this episode, John talks to Emma Tracey about the challenges of teenage tics, being shut in a school cupboard by a teacher so he didn’t distract the class, and the impact the physical tics are having on his joints and muscles as he gets older.

Presented by Emma Tracey Sound mixed by Dave O’Neill Produced by Emma Tracey and Cordelia Hemming Series producer is Beth Rose Senior News Editor is Lisa Baxter