In two revealing films for BBC2, Stephen Fry is to give the most frank account yet of the manic depression that led him to twice attempt suicide.
The comedian and actor will also interview fellow celebrity sufferers of depression, including Tony Slattery, Carrie Fisher and Richard Dreyfuss. More than a decade after he walked out of the West End play Cell Mates following bad reviews, and contemplated suicide before disappearing to mainland Europe, he retraces his steps in Stephen Fry - The Secret Life of the Manic Depressive, to be shown this autumn.
"Eleven years ago, in the early hours of the morning, I came down from my flat in central London to this lane. I went into my garage, sealed the door with a duvet I brought, and got into my car. Sat there for at least, I think, two hours in the car, my hands on the ignition key. It was a, you know, it was a suicide attempt not a cry for help.
"[Later] I drove to the south coast and took a ferry to Europe. I just knew I couldn't be at home. I really believed I would never come back to England. I couldn't meet the gaze of anyone I knew."
After a week, Fry secretly returned to the UK, and at the age of 37 was diagnosed with bipolar disorder by a doctor. He subsequently spent three months in Santa Barbara in the US, undergoing therapy.
The comic, who turns 50 next year, also attempted suicide at 17. "I took as many tablets as I could, and as many variations as I could, in order to make them as toxic as possible. Unfortunately, it just made me projectile vomit and I do remember, absolutely, that it was a suicide attempt, not a cry for help," he tells a bipolar research specialist in one of the two prime-time documentaries. Fry hopes the films will help to break the taboo over mental illness.
"I have discovered just how serious it is to have bi-polarity or manic depression, as it's also called. Four million others in the UK have it and many of them end up killing themselves," he said.
"So, 10 years on, in these two programmes, I'll tell you what I've found out about my mental illness. I'll talk to others who have it about how they cope, both with the illness and the stigma surrounding it."
Some of his conclusions are surprising. The comedian Tony Slattery describes in the programme how he fell into "a pool of despair and mania", renting a warehouse by the Thames where he didn't see anyone for months.
But when Fry asks him, if he could, would he press a button, and get rid of his bi-polarity, Slattery says he would "keep it", because it is part of who he is.
The show's producer, Charlotte Moore, said: "Stephen decided he wanted to talk about it, because a lot of people don't talk about it, because of the taboo around mental health. It's a very misunderstood condition. He thought he could use his programme to make a difference."
Other highlights of BBC2's autumn season include Tsunami - The Aftermath, two 90-minute films about the 2004 Boxing Day tsunami, filmed on location in Thailand. The fictional drama will explore the mistakes made by the Foreign Office in handling the aftermath of the disaster.
The Thick of It creator Armando Iannucci returns with a new sketch show, Time Trumpet, imagining what Tony Blair, David Beckham, Charlotte Church and Alastair Campbell might look like in 30 years' time.
TV gardener Monty Don takes on the challenge of working with young offenders addicted to heroin, teaching them to look after a garden in an attempt to change their destructive behaviour. A drama documentary series, Nuremberg, will mark the 60th anniversary of the execution of senior Nazi war criminals. In his first major TV series since A History of Britain, Simon Schama investigates the making of eight masterpieces in Power of Art. And Adam Curtis, the producer of the award-winning Power of Nightmares, returns with a new series about the death of altruism and the collapse of trust.
Life and times of Stephen Fry
BORN 1957, Hampstead, London. Grew up in Norfolk
EDUCATION Uppingham School, Rutland. Absconded with a stolen credit card and spent three months in Pucklechurch Prison, for fraud
FURTHER EDUCATION Queen's College, Cambridge: 2:1 in English. At Cambridge Footlights he met friend and collaborator Hugh Laurie. Appeared on University Challenge
LIVES London and Norfolk
1984 Rewrote script of Me and My Girl, which became a huge West End hit and made him a millionaire
1980s Weekly column in The Daily Telegraph
1986, 1989 Appeared in two series ofBlackadder
1992 The Liar published. Has written three more novels
1992 Peter's Friends. He has acted in more than 20 films
2003 Debut as film director: Bright Young Things, adaptation of Evelyn Waugh's Vile Bodies.2006: Won the Rose d'Or award for Best Game Show, for QI
INTERESTS High-profile supporter of the Aids charity the Terrence Higgins Trust