The biggest surprise about the flat and predictable The Roommate is that it’s debuting in movie theaters rather than on Lifetime or TruTV. As an off-the-meds schizophrenic co-ed who develops an unhealthy fixation on her roomie, Leighton Meester does a fairly credible job given the circumstances presented to her by writer Sonny Mallhi and director Christian E. Christiansen. Minka Kelly is less excusable as the pretty object of Meester’s obsessions—she mostly tosses her hair and smiles, occasionally furrowing her brow in an attempt to convey thoughts and emotions (or gastrointestinal distress). It would be charitable and misleading to describe The Roommate with terms like “thriller” or “slasher,” because that would indicate some level of activity and stimulation. The only stimulation here is the occasional belly laugh, like when Billy Zane shows up to play a sleazy fop for the 68th time.