The pressures of modern-day adolescence — that ongoing struggle to participate in dozens of extracurricular activities, score good grades and find the perfect prom date — is a familiar topic for movies, especially for those of us who grew up on John Hughes’ works of the 1980s, such as “Sixteen Candles” and “Ferris Bueller’s Day Off.”

But this subject has never been tackled with such foursquare emotion and sincerity as it is in “It’s Kind of a Funny Story,” Ryan Fleck and Anna Boden’s delicate, affecting new comedy-drama set almost entirely within an adult mental ward at a New York City hospital.

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Zach Galifianakis, right, and Keir Gilchrist in "It s Kind of a Funny Story." Focus Features

That’s where 15-year-old Craig Gilner (Keir Gilchrist) checks himself in after a difficult night: He keeps having suicidal thoughts and doesn’t know where else to turn. With the adolescent section of the ward closed, Craig is placed among adults, and he immediately regrets his decision to come to the hospital. But the head doctor (Viola Davis) says he has to stay a minimum of five days for observation.

As Craig makes his way around the hospital, he meets a predictable array of oddballs: A Hasidic Jew (Daniel London) who insists on extreme silence. His Egyptian roommate (Bernard White), who refuses to get out of bed. Zach Galifianakis (“The Hangover”) turns up as a ne’er-do-well whose avuncular manner masks a crippling anguish. Emma Roberts (“Nancy Drew”) plays the pretty young girl who strikes up a romance with Craig.

It all might easily have turned cloying and cutesy — and, no doubt, directors Fleck and Boden flirt with the cliche of mental hospital patients as eccentric cartoons at whose expense we can enjoy a few chuckles.

But as with their previous efforts, “Half Nelson” and “Sugar,” this new film (based on a young adult novel by Ned Vizzini) is suffused with a tremendous empathy for its characters. Gilchrist, who is in virtually every scene of the film, does an extraordinary job capturing Craig’s sense of self-doubt and dismay without ever losing sight of his core of sweetness and decency: His problems may seem petty, but they’re his problems, and they matter.

From start to finish, “It’s Kind of a Funny Story” walks an uncommonly deft line: Playful comedy gives way to moments of shockingly immediate and honest emotion (watch out for Galifianakis, whose revelatory in a scene where his character breaks down after having blown an interview for placement in a halfway house).

And smack in the middle comes a tour de force of sorts, a fantasy musical number set to Queen and David Bowie’s “Under Pressure” that shows us a group of damaged people coming together to find a moment of repose and sanctity. You genuinely don’t know whether to laugh or cry, so you end up doing a little bit of both.

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