Gay actor Stephen Fry will reveal his struggle with depression and suicide contemplation in a new BBC documentary highlighting the condition later this year.

The screen and stage star, presenting BBC2′s The Secret Life of A Manic Depressive, will recount the time he walked out on the West End play Cell Mates in 1995 and sat in his car considering whether to turn on the ignition and kill himself with the exhaust fumes.

Fry, 48, said: “I went into my garage, sealed the door with a duvet and got into my car, I sat there for at least two hours in the car, with my hands on the ignition key.”

He will interview other celebrities including Carrie Fisher and Richard Dreyfus who have been diagnosed with bipolar condition, a form of manic depression which doctors discovered in Fry at the age of 37.

“I’d never heard the word before, but for the first time at the age of 37 I had a diagnosis that explains the massive highs and miserable lows I’ve lived with all my life,” said Fry who first tried to kill himself at the age of 17.

“There’s no doubt that I do have extremes of moods that are greater than just about anybody else I know,” he said.

The documentary will be broadcast in the autumn.