What's at the root of self-destructive depression? Adam Salky's exercise in kitchen-sink miserabilismI Smile Backdances around some possible causes before discarding them entirely. Laney (Sarah Silverman) is a well-to-do but deeply troubled New Jersey housewife who eschews her prescribed lithium in favor ofBad Lieutenant-levels of sex, drugs, and depravity. She pretends to be engaged with life the way that's expected — she smiles back, as it were — but it's all a façade, one that grows increasingly meaningless as she grapples with that fact that everything and everyone is going to die. What's the point of love, or even pretending that things are going to be okay when they so clearly will not? Plenty of narrative threads are left dangling, but the point ofI Smile Backis not the details of Laney's life, but how she deals with those details; her son's piano recital of Beethoven's "Ode to Joy" — irony! — might be one of the most suspenseful sequences of the year, while an early scene sets a bar for teddy bear-based vulgarity theTedfilms could never hope to reach. As studies in female depression go,I Smile Backis less satisfying as a cohesive film than the recent Kumiko, The Treasure Hunter, but Silverman's vanity-free performance is a treasure in its own right.