Justin Theroux ''made a lot of mistakes'' when he was younger.

The 'Leftovers' star, who is engaged to Jennifer Aniston, admits he deeply regrets some of the acting roles he took on in the past and ''wanted to hang'' himself on the set of an unnamed crime series.

The 43-year-old star said: ''I've definitely made mistakes when people say, 'You should do this,' or 'This is a great director. I know the part's not what you want, but you should do that.' I've rued many days on set where I've been like, 'Why did I say yes to this?' I made a lot of mistakes as a younger actor, signing up for plays I'm stuck doing for six months. I've been in many sad situations.''

Discussing his worst job in Hollywood, he told The Hollywood Reporter at its annual TV Drama Actor Roundtable: ''I did a television show a long time ago, like the early '90s -- a cop procedural -- and the volume of work that you had to do to do 24 [episodes] was just crushing. And it's not necessarily the material you're loving, and you're showing up at 4 a.m. on a Monday and leaving at 4 a.m. on a Friday.

''You're having to cycle through your bag of tricks so much that you start to fall into bad habits.

''I wanted to hang myself. My character said s**t like, 'Chief, you're going to want to hear this!' You go, 'Oh, I can't.' ''