The TV presenter, 46, said that despite being clean since she was 25, she’s certain that if she was to drink she would go straight back to drugs.
Speaking to a UK newspaper, she said: “Drugs helped me stop feeling so insecure about what people thought of me. And I really cared about what people thought. So you do things to make people like you.”
The mum-of-three revealed that heroin was her drug of choice, saying: “Heroin makes you forget everything, no problems, no worries, no anything.”
Former Big Brother presenter Davina said that when she drinks, ‘my willpower completely goes out the window.”
She might have been clean and sober for over 20 years, but Davina can still spot others who aren’t.
She said: “I can still spot people going into toilets in twos. I can see hand gestures, I can see packets being passed to each other, I can see it from a million miles.
“If I’m sober I just think, oh, good for you. If I’m drunk, I’d be thinking, I wonder if I could just go and hang out, and if somebody asks me or invites me in, then I’m powerless and I should just say yes.
“Some people maybe can start drinking again, but I just know that I can’t.”
Davina recently undertook an extremely challenging task for Sport Relief, for which she ran, cycled and swam 500 miles.
The challenge, from Edinburgh Castle to London, raised over £760,000 for BT Sport Relief.