"Funny People" is Judd Apatow's third film as a writer-director — and the first in which he sets aside all the tomfoolery and gets down to dramatic business.

This is still a comedy, with laughs as big as the ones in "The 40-Year-Old Virgin" and "Knocked Up." There just aren't quite so many of them, and there are none of the fanciful shenanigans at the movie's edges that gave those other pictures their vaguely surreal airs: No musical numbers; no odd and kooky stoners; no improvisational riffs in which the actors take off on ad-libbed tangents. Well, almost none of those.

A lot of "Funny People," in fact, plays like the scene in "Knocked Up" in which a married couple erupted into such a vicious and profane argument you wondered if you really should be laughing. There is certainly nothing funny about the new movie's early scenes, in which an Adam Sandler-esque superstar, George Simmons (Adam Sandler), learns he has a rare form of leukemia and only months to live.

George has made a fortune starring in low-brow movies such as "Merman" and "My Best Friend Is a Robot," but his wealth and fame have alienated him from the world. He lives alone in a mansion and he has practically no close friends outside of show business.

So instead of telling anyone his bad news, George hires aspiring standup comedian Ira (Seth Rogen) to serve as his all-in-one assistant, confidant, apprentice and nursemaid.

"Funny People" is unusually long for a comedy — 2 hours, 25 minutes — primarily because of all the supporting characters, such as Ira's roommates and the beguilingly odd young woman (Aubrey Plaza) Ira hopes to date.

But the heart of the movie is the relationship between George and Ira, which continues after the leukemia goes into remission, as the film's inescapable trailer has already revealed. Like "Punchline" and "Lenny," "Funny People" belongs to the self-analytical genre of comedies that delve into the often dark and unfunny psyches of people who make others laugh for a living.

If "Funny People" seems unexpectedly abrasive, that springs from Apatow's decision to make George a not-entirely-likable protagonist — a man willing to manipulate and use everyone around him, almost by instinct, the result of his long having been surrounded by sycophants and yes-men. This is Apatow's emotionally darkest, least-genial film, and an exceptionally good and subtle Sandler embraces the duality of a man beloved by the world who secretly hates everyone.

Rogen gives his fullest and most realized performance to date as Ira, the young comic craving his big break who hasn't yet been corrupted and made cynical by the industry. In one of the film's best running gags, the eager Ira constantly tells people things they're not supposed to know, intending to help but instead always leading to trouble.

"Funny People" is probably too long and unwieldy for the simple story it tells, but the movie's power sneaks up on you, a combination of the sweet and the sour — because even funny people aren't always being funny.