Mark Ruffalois doing double duty for HBO’s new miniseries,I Know This Much Is True.

In the show, theAvengers: Endgamestar, 52, plays identical twin brothers, Dominick and Thomas Birdsey, the latter of whom is schizophrenic.

“Your brother is seriously ill,” Rosie O’Donnell‘s character Lisa Sheffer tells Dominick.

The trailer also jumps between the Birdsey twins’ present-day life and their relationship growing up as children.

“I need you to stand up for me for once,” one of the twins tells an unknown person — and from there the trailer delves into action overdrive, turning into chaos with drama and tears.

Melissa Leo, Archie Panjabi, Imogen Poots, Juliette Lewis and Kathryn Hahn also star in the miniseries.

Mark Ruffalo.

Mark Ruffalo Plays Troubled Twins in I Know This Much Is True Trailer

Due to Thomas’ years of dependency on medication for his schizophrenia, Ruffalo said he gained weight to accurately portray the effect medications and “mood stabilizers” can have on someone’s body.

“We didn’t want it to be like I run and throw a wig on and do the same scene in the same day, so we took six weeks off to really separate these two guys,” Ruffalo explained. “And Thomas is on medication, mood stabilizers and anti-psychotics. A lot of people put on weight.”

“Putting on the weight for Thomas was really challenging,” he added. “I didn’t expect it to be. I thought I was going to have a fun time doing that, but when you’re force-feeding yourself, some of the romance of food sort of leaves.”

Mark Ruffalo

The Emmy Award-winning actor also admittedhe was scared to take on the role of Thomasbecause he knew how important it was to portray him accurately andspread awareness about an “important issue.”

“It means a lot to me to be honest with that, which means going into that world and getting to know it and getting comfortable with it,” he said.

“And that’s challenging, and so that aspect of it was challenging…I was really afraid to play him,” Ruffalo added. “I think it’s really an important issue, and I want to tell it as honestly as possible. The responsibility is on me.”

I Know This Much Is Truepremieres April 27 on HBO.

source: people.com