"Scrubs" star Zach Braff returns to the perennial theme of going home again with "Garden State," his directorial debut, in which he pays homage to such classics as "The Graduate" and "Harold and Maude." "Garden State," which Braff wrote and also stars in, won't join those films as either an instant classic or a cult phenomenon; it feels too slight to qualify for such canonical status.

But this wistful comedy, in which Braff plays a 26-year-old New Jersey native unexpectedly reconnecting with family and friends, will no doubt resonate with its immediate audience of young people who don't feel as if they've started their real lives yet. What's more, "Garden State" features some wonderful performances, chief among them an engaging, even courageous turn from Natalie Portman.

As "Garden State" opens, Andrew Largeman (Braff) is having a nightmare in which he's on a crashing plane; while panic ensues all around him, Andrew -- or "Large" as he's known to his friends -- calmly reaches up and adjusts the air conditioner knob above his head. That pretty much sums up Large. He's numb, floating through his life as a struggling actor in Los Angeles behind the prophylactic haze of prescription drugs and post-teenage anomie. He isn't jarred out of his emotional detachment by a call from his father (Ian Holm) telling him his mother has died; rather, when he returns to New Jersey for the funeral, he still affects the same quizzical, slightly slack-jawed air of bemusement.

It isn't until he meets a girl named Sam (Portman) that Large begins to wake up, and the few days he spends with her -- as well as an old high school buddy and committed pothead named Mark (Peter Sarsgaard) -- start to jog him out of his funk. Gradually, viewers come to learn the circumstances of Large's state of mind, and there's a satisfying catharsis during the film's climactic sequence, when Large finally comes to terms with a difficult family history. But mostly, "Garden State" is a sweet, winsome romance, punctuated by moments of sharp, observant humor.

That humor is often delivered in the form of sight gags, which Braff executes with dexterity, even if the bits don't always advance the story. Indeed, many scenes in "Garden State" don't have a conventional payoff; their point seems to be some kind of visual punch line. Still, the set pieces are undeniably witty, and they provide a lively context for the largely interior conflicts and quests the protagonist is going through.

Because Large is for the most part a passive cipher, the supporting characters of "Garden State" are all the more crucial. Braff has cast those roles well, enlisting Sarsgaard -- who has delivered terrific performances in "Boys Don't Cry" and "Shattered Glass" -- as a red-eyed stoner and grave robber who somehow manages to become the hero of the story.

And as Sam, an impulsive, life-loving free spirit who could be the younger sister of Kate Winslet's character in "Eternal Sunshine of the Spotless Mind," Portman proves what a versatile actress she can be. Viewers will no doubt laugh at the droll visual one-liners throughout "Garden State" -- the sight of Braff standing against floral wallpaper in a shirt made from the same fabric; a seeing-eye dog humping Large's leg; a Medieval Times waiter, in full armor, eating a bowl of Lucky Charms -- but it's Portman's performance that will stay with them. In a role that demands tears one moment and tap dancing the next, she takes what might have been merely an ironic or self-indulgent exercise and brings it to warm, wacky life. She even inspires a person to use words like "warm" and "wacky" without gagging, a fact that Large would surely agree makes Sam the best of several very lovely things about "Garden State."

Garden State (102 minutes, at Landmark's E Street Cinema, Landmark Bethesda Row, Loews Georgetown and Cineplex Odeon Shirlington) is rated R for language, drug use and a scene of sexuality.

Peter Sarsgaard, left, and Natalie Portman help Zach Braff reconnect with himself and his family in "Garden State."