Making a comedy about mental illness sounds like a challenge, but according to "It's Kind of a Funny Story" co-star Zach Galifianakis, performing as a goofy-but-depressed institutionalized patient was... easy.

"The character in the movie is more similar to me than anything else I've been involved with," "The Hangover" actor told HitFix in an interview. "I mean that's not the greatest endorsement for your own personality but... it came pretty easily."

The 40-year-old comedian also said some outside research helped. "It is a movie about mental illness, so I studied old tapes from the Bush Administration."

One of the films highlights includes a music video sequence, with the patients in the hospital performing to Queen and David Bowie's "Under Pressure." Galifianakis says it helps that he and his parents would lip-sync to Earth Wind & Fire when he was a kid.

But that's not the only musical moment in the film: Canadian rockers Broken Social Scene provided much of the score and backing tracks to "Funny Story," which was adapted from the book of the same name.

"Broken social scene by coincidence is like my favorite band of all time," the actor endorses.

He also endorsed the script to much-anticipated "The Hangover 2," which starts shooting "very soon... The movie was such a big thing, it'll be hard to top that. But as far as the script goes, we're half way there."

"It's Kind of a Funny Story" is out in theaters on Oct. 8.