The Glaswegian Late Late Show presenter has revealed that he considered killing himself after running up debts of £250,000.

In his memoirs, which are due to be published next week in America, he also describes how he began experimenting with drugs while growing up in Cumbernauld which he describes as a “gloomy wasteland” blighted by sectarianism and violence.

Ferguson who moved to the US in 1994 and is now teetotal and drug-free, said he had reached back “into the darkness” while writing his autobiography, American On Purpose.

He admits he smoked heroin after being encouraged by friends but claims he never injected the drug.

He recalls how he screamed in terror in Glasgow’s Kelvingrove Park during one terrifying experience with LSD, which persuaded him to switch to alcohol.

He describes how he was arrested and taken to the city’s Stewart Street police station after attempting to break into a car while inebriated. His lowest point came in London on Christmas Day in 1991 after he missed a flight home to Glasgow.

He said: “I was checking out and that would be the end of it. I knew what I would do: walk down to Tower Bridge and swan-dive into the dark Thames.” But on his way out of the hotel, a friend offered him a half pint of sherry and he embarked on another drinking binge which he claims saved his life.

Ferguson went into rehab soon after and his career blossomed.

As one of America’s most popular chat show hosts, he performed in front of George Bush at the White House.

He recalls how the ex-president, himself a former heavy drinker, reminisced about a trip to Scotland and “expressed puzzled awe at the amount of drinking that was done there”.