Harry Potter star
says he started drinking to deal with the pressure of being famous.
The 24-year-old admitted that he found himself struggling to deal with his celebrity status and the adoring fans, reports dailymail.co.uk.
On occasions, he would even turn up to filming still drunk from a boozy session the night before.
Read: It'll be a horrible move to date a Harry Potter fan: Daniel Radcliffe
He said: "I would have benefited from not drinking as it was not making me as happy as I wanted it to. It is not a real pressure but it is a pressure of living with the thought, 'Oh, what if all these people are saying I am not going to have a career?
"'What if they are all going to be right and will be laughing and I will be consigned to a bunch of Where are they now? lists?'"
The actor, who has been teetotal since 2010, is now known for his theatrical work rather than Harry Potter.
"People don't shout Harry Potter at me now, they tend to know my name, which is lovely... (but) I always will credit the opportunities I get to Harry Potter. I would not be a happy person if I was bitter about those 10 years of my life," he said.