British actor Dominic Monaghan was left in a deep depression after spending four years filming and promoting The Lord Of The Rings trilogy of films - and he credits co-star Billy Boyd with helping him regain his positive outlook.

Monaghan, who currently stars in Emmy Award-winning drama Lost, played hobbit MERRY in director Peter Jackson's adaptations of JRR TOLKIEN's fantasy books, but he admits his rise to fame left him feeling empty.

The 28-year-old says, "I wasn't taking care of myself. I was sleeping in the day and getting up at night. I wrote 50 journals in a year.

"I'd never been depressed so I didn't understand it. I felt like I had a big weight on my chest."

Monaghan will always be grateful for the support he received from fellow hobbit Boyd: "Billy was a big help. He reminded me of why I wanted to be an actor and I had days where I could see the magic.

"I think it will be a long time now before I could go back into that hole."