Infinitely Polar Bear

There’s no one right way to show mental illness in the movies, yet there are hundreds of ways to get it wrong. Even though certain disorders come with specific traits, a diagnosis is not a human being, and doomed is the actor who just cycles through symptoms, rather than working from the inside out. In writer-director Maya Forbes’s debut, Infinitely Polar Bear, Mark Ruffalo plays Cam Stuart, a dad diagnosed as manic-depressive, who suddenly faces the formidable task of being the chief caretaker of his two young daughters. What makes the performance work so beautifully is that he doesn’t reduce his character to a series of behavioral tics: He’s always a person first. We ride his highs and lows with him just by looking into his eyes. We know what Cam’s feeling, even when the drugs he’s on are doing their damnedest to prevent him from feeling it.

Forbes, a longtime writer and producer for TV, drew from her own experience growing up in 1970s Cambridge, Massachusetts, with a manic-depressive father. Can a man who’s shakily unpredictable get his kids off to school on time and make their meals? Ruffalo's Cam thinks he can; he’s only partly right.

At times Infinitely Polar Bear veers dangerously into what Pauline Kael once called "He’s not crazy, he’s special!" territory. But Ruffalo is so good, he can pull that off. And Zoe Saldana, as the wife who has to trust him, matches him beat for beat: The look in her eyes, when she realizes that her children are seeing just a husk of the man they know and love, is a delicate jumble of protectiveness and tempered anguish.