Mel Gibson has extended a hand of sympathy to Shia LaBeouf.

The Transformers star, 28, is receiving voluntary treatment for alcohol addiction after some recent bizarre behaviour, including attending a premiere with a paper bag over his head and being arrested for disrupting a Broadway play.

Mel, 58, told IndieWire: "It's a hard world. You're under a microscope. The loss of personal anonymity forever is a hard pill to swallow.

"You don't get an opportunity to put the toothpaste back in the tube. It never goes back in."

He continued: "You're a target. And you have to be really adept at tap dancing and dodging the bullets. And sometimes you get hit, and sometimes mortally. It's pretty bad."

The actor added: "When I see someone like Shia LaBeouf with the bag on his head and stuff, my heart goes out to the poor guy because I think he's suffering in some way or why would he do that?

"People are inclined to sort of point the finger at him and say that he's this, that, or the other. It's easy to judge. But I'm sure he's going through some kind of personal, very painful, cathartic thing that he has to exorcise and get out there."

Mel, who has battled alcoholism, added: "He'll probably play it out and come back... He'll be all right. I actually like the kid. I think he's good. I've never met him."