Daniel Radcliffe: 'I was drunk during Harry Potter filming' In his latest interview, Radcliffe admitted being drunk while on the Harry Potter film sets although he does not disclose which ones. He has said that his life went off the rails for a period when he turned 18 and was filming Harry Potter and The Half-Blood Prince as the pressures of fame made him so dependent on alcohol. I have a very addictive personality. It was a problem," Radcliffe told Heat magazine this week in an interview to promote his latest film. People with problems like that are very adept at hiding it. It was bad. I don't want to go into details, but I drank a lot and it was daily - I mean nightly. I can honestly say I never drank at work on Harry Potter. I went into work still drunk, but I never drank at work. I can point to many scenes where I'm just gone. Dead behind the eyes. "You either have to change something or give into that shame," he added. The British star, propelled to fame aged 11 after being cast to play the boy wizard in the movies based on J.K. Rowling's bestselling novels, also admits to a "very busy personality." In the interview he also disclosed that his production-assistant girlfriend, Rosie Coker, was "a wonderful, wonderful girl, who's far too good for me." I can also be quite insecure. A lot of actors have self-doubt. I live under that the whole time, and it's how I function best. I think she puts up with a lot; she says she doesn't," said Radcliffe. Radcliffe has received critical acclaim for his theatre work in the Broadway and West End productions "Equus" and "How to Succeed in Business Without Really Trying." He is currently promoting his current film, "The Woman in Black," a neo-Gothic horror movie, which opens this week, is his first post-Potter film. The eight Potter films grossed more than $7.7bn (£4.87 billion) worldwide at the box office and made stars of Radcliffe, Emma Watson and Rupert Grint.