Where exactly lies the line between wild lover and deluded maniac? In the wacky, exhilarating "Silver Linings Playbook," the border is as thin as onion skin, if it exists at all.

After eight months in a psychiatric hospital, Philadelphia high school teacher Pat Solitano (Bradley Cooper) is back with his blue-collar parents (Robert De Niro and Jacki Weaver). He's all set to start over and win back his ex-wife. Sure, he's had a couple of rough patches. There was the time he beat the daylights out of her lover. And yeah, he goes furniture-tossing berserk whenever he hears "Ma Cherie Amour," their wedding song. And there's the restraining order.

But Pat's got a plan to turn his life around with a Great Books reading list, plenty of exercise and a positive attitude. What could possibly go wrong? When Pat throws "A Farewell to Arms" through a closed window because he can't handle its tragic ending, you realize the answer: Everything.

A truly decent guy, except for the violent, unstable part, Pat white-knuckles his way through every social interaction. When his friend Ronnie (John Ortiz) and his wife, Veronica (Julia Stiles), have Pat over for dinner, they also invite Veronica's sister Tiffany (Jennifer Lawrence), a new widow. A bit kooky and a bit kinky -- she worked through her grief by sleeping with every single person in her office -- Tiffany is the only person able to stay a step ahead of Pat's manic behavior. The rocks in her head fit the holes in his. Tiffany promises to help Pat mend things with his wife in exchange for one little favor.

With a résumé including "Spanking the Monkey," "Flirting With Disaster," "The Fighter" and now "Silver Linings Playbook," director David O. Russell is becoming to freaky family dysfunction what Scorsese is to the Mafia.

He loves awkward, unmanageable people, adores the energy of a good fight, thrills to rat-a-tat dialogue with the camera swinging from face to face. He brings out the best in his cast by making them dive to the bottom of conflicted, multi-dimensional characters.

Cooper is inspired, leagues beyond the labored comic shtick of the "Hangover" movies, and plays his rapturous self-delusion cannily. Positive-thinking Pat is ready to follow his strained optimism right off a cliff.

Lawrence shows a new audacity. She moves like a whirlwind as Tiffany, spitting sass and sarcasm at anyone who thwarts her. She overpowers or ignores people -- she cannot deal with them. But is she the firm hand Pat needs, or the trigger for his next blowup?

As Pat Sr., a superstitious, obsessive-compulsive sports bookmaker, De Niro does his best comic acting in ages. Weaver, so chilling in the Australian crime saga "Animal Kingdom," is sweetly daffy and surprisingly duplicitous as the woman of the madhouse.

Russell succeeds by refusing to simplify his characters or his ideas. Although "Silver Linings" is a romantic comedy, it's an anarchic example of the form. A petty father-son squabble turns into a terrifying physical brawl. A big dance number bristles with intricate clowning and builds to a 10-kiloton sight gag. The cheerful ending is not so pat as it seems when you reflect on the amount of manipulation and lying it took to achieve it.

"Silver Linings Playbook" tells us that happily-ever-after may depend on finding people who coexist with our lunacy, not ones who can lead us out of it. In any case, it's crazy good.

Colin Covert • 612-673-7186