One day my parents said they were taking me to Uncle Dan's

A new BBC drama about a boy put into a mental hospital by his parents stars Mike McShane. And why not? He was that boy, after all. By Elizabeth Udall

Chris Bould's film The Nicholas Brothers had just won three awards as well as a Bafta nomination for Best Arts Documentary, when he was called in to see Peter Cregeen, then head of serials and series at the BBC. Bould was still on a high as he pulled his latest idea for a horror anthology from his briefcase. "Peter just looked at me," Bould recalls. "He said, `We don't like anthologies'. "

Desperate, Bould produced a screwed-up piece of A4 out of his back pocket. On it were scribbled two sentences: "One sunny day in 1972, my parents packed me into the car and told me they were taking me to Uncle Dan's. Then, at the crossroads, they turned left instead of right and they took me to a loony bin." Within seven days a script had been commissioned.

The film, Crazy for a Kiss, was made under the BBC's Screen Two banner with a shooting schedule (21 days) and a budget (£900,000) to suit its status. Yet it has now been transferred to 35mm film and is being considered as an entry at next month's Cannes film festival.

The star of the film is the American actor and comedian Mike McShane. He was the obvious choice: those scribbled sentences had, after all, been his. And they weren't simply a fragment of an idea, they were a snapshot from his life.

"The basic plot, someone being unceremoniously dropped off at a mental hospital when he thinks he is going somewhere else, is absolutely true," says McShane. His adoptive parents left their 14-year-old son in a Midwest psychiatric clinic for six months. "They were older than most of my friends' parents. They had just been settling down into their golden years when - whoa! - there I was.

"I was expelled from school, I had difficulty distinguishing between fantasy and reality and I was happy one day and depressed the next. We'd been for family counselling but it was always, `We're OK, it's him, there's something wrong with him'. They left it to the doctors to figure out." The figuring out process included electric shock treatment and periods in "iso" - a solitary confinement cell whose walls were gnarled from the desperate clawing of other inmates. "The experience had a profound effect on the rest of my life."

It was while McShane was in New York with Chris Bould filming Broadway Stories for Channel 4, that Bould suggested he return to the hospital to "exorcise some ghosts". From their conversation on McShane's return was born the idea for Crazy for a Kiss.

"I did say at an initial meeting that I would play the young Mike, kind of like an Alan Bennett piece," McShane recalls. "I had to tell them I was joking. Midwesterners have irony plenty..." The American actor Shaun Weiss was cast as the young Mike, while McShane opted to play Harley - a hospital orderly who cared for him.

Clive Brill, the film's producer, asked the writer Greg Snow to adapt McShane's notes. Snow had also been in a "loony bin" in his early twenties. "I thought Greg and Mike would hit it off," Brill explains. He was wrong.

"He's from that whole Cambridge scene, a friend of Stephen Fry," McShane says. "It's all, `Hello darling, hello love, have another port.' I'm like, `Here's a beer, here's the football, welcome to the Midwest'." Greg used to write things that an American wouldn't say. He told me no one would notice. I told him I'd notice. It was about my life. I admit I was very emotional, but after a week I wanted to kill him."

Snow defends the language charge. "Every American who read it thought an American had written it," he says. "I was given only one correction, ever." At one point, McShane was so unhappy with Snow's script that he produced one of his own. "It was full of pain," Snow says. "It wasn't a piece of entertainment.

"Of course I have tremendous sympathy for what he went through, and it was very generous of him to ever let the film go ahead. But Mike didn't want to upset his parents by trivialising or mocking the episode... they'd have had heart attacks if they'd seen his version. He's obviously still scared of them, even though they're 80 years old now."

Mike's insists that his parents are "cautious and optimistic", that they want him to be "creative" and that he worked on the film "with their blessing".

Just as McShane and Snow disagreed over the film's tone, so did the producer and director. The BBC, criticised for the dour content of the majority of its Screen Two films, wanted Crazy to be a comedy. "Clive said it was a comedy, I felt it was a drama with funny moments," Bould explains. "I agreed with Mike that there should be dark things in there.

"Mike could never divorce himself from the absolute truth," Brill adds. "He'd say Greg's script wasn't heavy enough, but our intention was not to make a depressing film. The idea was that at the end the audience would go away feeling there was hope for Mike, that his life would improve."

The BBC is now billing Crazy for a Kiss as a "riotous comedy ... One Flew Over the Cuckoo's Nest meets Animal House". They are also using it to open "States of Mind", a season of programmes about mental health. So did everyone get their way in the end?

"I spent two years talking about what happened to me for this film, looking at it from different angles," McShane says, "but I still feel angry." Nevertheless, he admits that by the time filming started he was happier with the script: "It's like when you pack things for a holiday that you are convinced you'll need, but when you get there they never come out of the case."

Snow is in a buoyant mood, and very pleased with the idea of a couple of weeks in the South of France. This is, after all, his first screenplay. "Cannes only take about 15 films for Director's Fortnight, so it's a real honour to even be considered... My poodle is being trimmed and I'm dusting off my heart-shaped sunglasses as we speak."

n `Crazy for a Kiss' : BBC2, Sunday 23 April, 10pm