'The Roommate' must be a psycho major

A timid thriller about a college girl who makes an unpleasant new friend, "The Roommate" is almost as naive as the coddled students who attend its fictional University of Los Angeles. Its most fiendish moment comes when one girl yanks out another's bellybutton ring. Not that - anything but that!

The film's cast comes straight from the world of lightweight teen television. Minka Kelly ("Friday Night Lights") plays Sara Matthews, an Iowa freshman with fashion-industry dreams; Leighton Meester ("Gossip Girl") is her unbalanced roomie, Rebecca, a Pasadena rich kid with major problems; the boyfriend role goes to Cam Gigandet ("The O.C.") as Stephen, a frat bro who plays drums for a post-Coldplay rock band. Together, they uphold a long Hollywood tradition of looking way too old and well-dressed to be teenagers.

The filmmakers are guessing you've seen enough fright flicks about identity assumers and personal-space invaders - "Single White Female," maybe "Poison Ivy" - so they don't feel the need to provide a motivation for Rebecca's behavior. She's just, you know, crazy, which is all the explanation you'll get for why she stalks Stephen in the library, attacks a professor (Billy Zane, fallen far from "Titanic") and totally messes up that girl's navel. It's a credit to Meester that she's reasonably convincing in her red-rimmed, whacked-out moments.

But Rebecca spends most of the movie being little more than a nuisance, lurking around in a hoodie and glaring at people. She also wears Sarah's necklace without asking. Anything but that!