Zach Galifianakis, a co-star of the summer smash The Hangover, is in negotiations to join Emma Roberts in It's Kind of a Funny Story, a coming-of-age comedy-drama from the duo behind Half Nelson.

The picture, based on Ned Vizzini's young-adult novel, tells of a teenage boy who, after a bout of depression, is sent to a mental institution, where he ends up in the adult ward and meets a number of offbeat adults as well as a quirky teenage girl.

The independently financed Focus Features project comes from writer-directors Ryan Fleck and Anna Boden. A shoot date this year is planned.

Galifianakis would play one of the main adult roles, while Roberts -- who is also in talks -- would star as the teenage love interest.

Galifianakis' stock shot up in Hollywood after his turn as a zoned-out, baby-carrying stoner in Todd Phillips' summer blockbuster The Hangover. He has taken on roles in a number of comedies, but Story would represent a meatier part with dramatic elements.

Galifianakis also is set for two comedic tentpoles for Warners -- the buddy road-comedy Due Date, which has wrapped production, and Hangover 2, which is set to shoot next year.

Fleck and Boden are coming off two critical darlings -- their Oscar-nominated Half Nelson and the immigrant-baseball drama Sugar.

HBO