I'm at a crossroads with Bradley Cooper. As much as I like him in his more serious work, I'm always surprised when he turns in a performance that strays from his name-making "Hangover" persona. I haven't been able to shake the idea that he's a born d-bag, but if anything can change my mind it's his thoroughly human contribution to "Silver Linings Playbook."

Cooper plays Pat Solitano, a teacher just released from an eight-month stint in a mental institution which he served for an outburst that subsequently left him jobless, homeless and wifeless. He's literally back at square one, living with his parents and under a restraining order from his wife, but Pat's embraced a fully optimistic outlook to get his life back on track – something he clings to with a dogged determination that's equal parts endearing and silly, especially in the face of the array of idiosyncratic people in his life.

Chief among them is Tiffany (Jennifer Lawrence), who is baggage personified after the death of her husband. She provides a sounding board for Pat, who up until now has been given free crazy reign over the film's emotional expression (think 4 a.m. tantrums over the ending of a book and the overall frank honesty of a 10-year-old boy). Better yet, she gives him a run for his money in the battle of wills for who's more inappropriate as a darkly comic, bitchy-because-I-can black sheep.

The evolving relationship between this Little Engine That Could and caustic cynic is what drives "Silver Linings." They connect because the rest of society doesn't know what to do with them, but their friendship begrudgingly develops as each discovers a practical use for the other – she as a pathway of communication to his wife, and he as a dance partner for an upcoming couples' competition.

Cooper and Lawrence are brilliant together, and it comes across with hilarious results. They're immature, selfish and fumbling, and this childish dynamic is only egged on by the nosy weirdos they call family. Tiffany's holier-than-thou older sister Veronica (Julia Stiles) does her meddling part, but it's Robert De Niro as Pat Sr. that takes the neurotic cake.

It's abundantly clear that the apple didn't fall far from the crazy tree upon meeting the Solitano patriarch, an obsessed high-stakes bookie with a serious superstitious streak for his Philadelphia Eagles. He comes into play in a major way toward the end of the film, but he gets a fair share of screen time throughout – which he uses to both bully and ingratiate himself into his son's life (and, eventually, the audience's good graces).

That's the way of most of "Silver Linings Playbook." It's subversively funny, and at the same time switches gears to serious so fast you're left with the smile from the last laugh still dumbly plastered on your face. It's a tumultuous mix, but the cast makes it work with good humor, heart and sincerity. The script, adapted from the novel "The Silver Linings Playbook," keeps things moving in the same spirit. It does begin to drift toward the climax, but doesn't stray too off-course before tying it all together for a sweet – if just as offbeat – finish.