Infinitely Polar Bear: Mark Ruffalo good, daughters better

The title of Maya Forbes’ movie, the TV veteran’s first feature outing as a writer and director, refers to her father’s bipolar disorder, and it captures the relative wistfulness with which Forbes and star Mark Ruffalo depict the illness.

Ruffalo, playing a fictionalized version of Forbes’ dad, pitches his performance toward the benign end of the manic-depressive spectrum. His Cam Stuart — chain-smoking, motormouthed, forcefully good-intentioned — is mostly the usual kind of cinema bipolar sufferer, more blandly embarrassing to his two daughters than truly mortifying, more absent-minded than neglectful. Ruffalo is as magnetic as usual but isn’t doing much he hasn’t done better elsewhere. He (and his onscreen wife here, a sharp-eyed Zoe Saldana) at least has fun playing 1970s dress-up. (The movie is set in a prettily autumnal Cambridge, Massachusetts, of 1978.)

Still, Infinitely Polar Bear works because Ruffalo tunes himself neatly to the two young actresses who play Forbes’ re-creations of herself and her sister (the Pink Martini singer China Forbes). Imogene Wolodarsky (Maya Forbes’ daughter) and Ashley Aufderheide convincingly capture the girls’ seesawing reactions to their unstable parent, sometimes patient with him as their understanding grows, sometimes angry that his condition seems to be splintering the family. Of the categories into which Forbes’ slight but well-wrought movie falls — Eccentric New Englanders, the Beat-Up ’70s, Dad’s a Big Goof, Everybody Loves Ruffalo — the one to file Infinitely Polar Bear under is Children See It All, thanks to the knowing Wolodarsky and Aufderheide.