He works in Haverhill Cineworld, has a degree in video production and hopes to start up his own freelance film company in the future.

But were Mark to tell people he has mental health issues, their opinions of him might change – and that is the reason for a 30-minute documentary he has made, which is now available to view online.

Because Mark, of Landseer Court, Haverhill, was diagnosed with bipolar rapid-cycling disorder earlier in the year, after many years of battling confusion emotions and behaviour, and experiencing a level of discrimination and mis-understanding.

"It's not as if my illness is me, or I am my illness, but it can be controlling," said Mark, who travelled 1,500 miles around the country to make the documentary, interviewing other people with mental health issues, including schizophrenia.

He first noticed changes in his behaviour when he was 19, experiencing extreme emotional highs and lows: "I would say or do things that were irrational, things that would be overtly random, when I was on a high.

"I think other people noticed it before I did, but it was quite a long process."

He had enrolled on a degree course at the then Buckinghamshire Chilterns University College, but started to find it hard to face people and missed a lot of his studies: when on a high, he was eager to do other projects and when experiencing a low, shunned company.

Turning to alcohol only enhanced the party-loving element of his highs, while deepening the depression he felt during his lows.

Realising he needed help, he went to his university doctor, but felt there was discrimination in the NHS towards people with mental health problems and it wasn't until he returned to Haverhill he started to get the help he needed: "They seemed to push me from one doctor to the next. The GPs here are a lot more helpful and referred me to the community mental health team."

Finally, a psychiatrist diagnosed him with bipolar rapid-cycling disorder in January, three years after his symptoms started.

The condition means his mood swings from extreme highs to severe lows rapidly - but it didn't stop him completing his degree on time - and his employers Cineworld are aware of his condition.

It has, he said, inspired an 'activist spirit' within him, which has made him want to try to educate people about mental illness.

"I found out there's a community, almost like a secret society, by the way we've been forced out of normal society. And I find the term normal society annoying.