Ewan McGregor admits he used to be a 'maniac' when drunk.

The 'Trainspotting' actor - who turned 40 on Saturday (31.03.12) - hasn't touched alcohol for 12 years but used to love drinking as much as his rock star friends.

He said: ''I used to hang out a bit with Oasis, and Damon Albarn was always knocking about somewhere or other, and like a fan I felt part of it.

''It was certainly a high point of my life. But it was also a time of massive debauchery - but then again, I was in my twenties.

''I got away with it more or less unnoticed. I was a maniac on the booze but I only remember it fondly.''

The Scottish-born star relocated from London to Los Angeles four years ago in a bid to escape the cameras, but admits he felt deeply ashamed following last year's summer riots in the British capital.

He told the Daily Mail newspaper: ''It was like mob culture. People were doing despicable things. They were angry but about what? All they achieved was to make everybody get even more conservative and tighten up.

''What happened in London made me feel embarrassed. It showed that there's unrest and dissatisfaction and that should be addressed.

''But people breaking windows in Foot Locker and trying on shoes before they steal them isn't saying anything other than, 'I'm a thief and I don't want to pay for my stuff'.''