“Silver Linings Playbook” serves as a textbook example of why directors matter. In any other hands, the adaptation of Matthew Quick’s novel would be the stuff of banal rom-com fluff or, perhaps worse, self-consciously quirky indie cliches.

Thankfully, this fractured fairy tale of mental illness, family drama, ragged romance and die-hard Philadelphia Eagles fandom has landed in the superbly capable hands of David O. Russell.

In 2010, Russell proved that he could breathe fresh life into the come-from-behind sports saga in the grittily uplifting “The Fighter.” Now, he returns to the kind of off-kilter family dynamics he became famous for with films like “Spanking the Monkey” and “Flirting With Disaster,” taking an all-too-familiar scenario of domestic dysfunction and injecting it with both spontaneity and heart.

As the movie opens, Pat Solitano (Bradley Cooper) is being discharged from a Baltimore psychiatric facility by his mother, Dolores (Jacki Weaver), having been sent there after an incident involving his estranged wife. Determined to embark on a new life of positive thinking (“Excelsior!” is Pat’s mantra), Pat returns to his childhood home, where his father, Pat Sr. (Robert De Niro), runs a small book-making operation, kept afloat by football bets, superstition and obsessive-compulsive habits that suggest where Pat Jr. learned his more questionable coping strategies.

Off his meds and “white-knuckling it,” Pat Jr. resolves to reunite with his estranged wife, Nikki; meanwhile, he meets Tiffany (Jennifer Lawrence), a sharp-tongued young widow with an acute nonsense-detector and a knack for brutal honesty equalled only by Pat’s own impulsive, socially disastrous candor.

“Everything’s under control,” says Dolores at one point. But nothing’s under control in this volatile petri dish of a world where emotions dart and glance off one another like so many highly charged pinballs. If “Silver Linings Playbook” often reverts to contrived devices — including a climax that features not just one but two all-important competitive showdowns — Russell choreographs them with a spare, unfussy forthrightness, as well as an unerring sense of place (crabby snacks and homemades share crucial supporting roles).

Perhaps most important, Russell doesn’t shy from the absurd humor mental illness can sometimes entail; nor does he make it look cute. Rather, “Silver Linings Playbook” invites viewers to consider whether we all don’t exist on some kind of spectrum, where the difference between a quirk and a symptom can be notional at best.

The tonal balancing act he pulls off is helped enormously by actors who never overplay or try too hard to be liked: De Niro delivers his warmest, most astute performance in years, and both Cooper and Lawrence successfully shed their movie-star glamour to play a couple of self-sabotaging misfits in search of a decent coping strategy.

From the moment they meet and compare medication history, Pat and Tiffany settle into a staccato, argumentative rhythm, with Tiffany bringing particular bite to their encounters (she has an utterly beguiling way of spitting when he does, after ambushing him during his daily jogging sessions). The tart, brutally frank chemistry that fuels “Silver Linings Playbook” plays out in the film’s visual approach, which eschews air-brushed Hollywood aesthetics for a far more jagged, intimate imperfection.

Still, Russell doesn’t deprive the audience of old-fashioned pleasures, including that rousing show-stopper toward the end. Would that every feel-good movie came by its good feelings so honestly.

R. Contains language and some sexual content and nudity. 117 minutes.

WASHINGTON POST-BLOOMBERG