Katie Holmes, Tom Cruise's ex-wife, is stars as a bipolar poet in the new drama "Mania Days." Katie Holmes, who became a household name starring on the 1998 TV series "Dawson's Creek."

The actress alternated her small screen roles by appearing in small, independent movies like "Wonder Boys" from 2000 and "Pieces of April" in 2003.

Holmes' new movie "Mania Days" premiered at the SXSW Film Festival on Sunday, March 15. Mania Days is set in and out of a psychiatric hospital. In the film Holmes plays a bipolar poet who falls in love with a bipolar man.

"I always thought it was going to be a hard project to pull off, because it was a character that was very different than anyone I played before," Holmes told Variety magazine. "I was very nervous to take on this project. I wanted to honor the disease and also find the humanity."

"Mania Days" was made for less than $1 million. The film was written and directed by Paul Dalio, who was diagnosed with manic depression as a teenager.

"I do think people will take her very seriously when they see this performance," Dalio told Variety. "I genuinely think it's going to open a lot of possibilities for her."

To research her character, Holmes talked with the director, consulted with doctors and studied books like Kay Redfield Jamison's "An Unquiet Mind: A Memoir of Mood and Madness."

"I just kind of gave into the role," Holmes told Variety. "Whatever came out, came out. I didn't plan on a different posture or way of walking. I didn't practice in front of a mirror. Maybe I should have, but I didn't. I get too self-conscious."

Holmes didn't attend the SXSW premiere because she is filming a recurring role on the Showtime series "Ray Donovan" in Los Angeles.

 "She's a little bit of a femme fatale, which is exciting for me," Holmes told Variety. "There's more shows on air, and a lot of people are choosing to do television," Holmes said. "It's really rewarding."