Another coming-of-age tale of teen angst in soulless suburbia, “Thumbsucker” comes across like a Lifetime movie with attitude–and a much better cast than that network’s usual list of TV has-beens. Like so many similar pictures, it’s being compared to “Donnie Darko”–but, as quickly becomes apparent, without cause. The earlier picture was also, to be sure, about a troubled teen. But it was imaginative, intellectually challenging and unafraid to perplex and even frustrate. By contrast “Thumbsucker” is merely a smugly quirky treatment of a familiar subject.

Essentially Mike Mills’s adaptation of a novel by Walter Kirn is the story of a high school kid, unable to outgrow the titular practice, who’s “cured” with a prescription for Ritalin, but finds that the medicine may be worse than the disease. As such it’s basically a cautionary tale for parents, of the sort that’s proliferated on cable, whether the danger involved is underage drinking, date rape or internet sex sites. What makes it superior to the usual run of such stuff is the fact that there’s so much talent in front of the camera. Lou Pucci, who plays the shy, introverted Justin Cobb, has the chance to take center stage here after occupying a secondary place as the villain’s loyal follower in the recent “Chumscrubber,” and with his long, stringy hair and morose manner he makes an intriguing subject. But though he goes through the script’s succession of changes well enough–transforming himself first into a wild, destructive kid when hypnosis breaks him of his habit, then into a brainy star of the school debate team when the drug takes charge, and finally into a pothead with a strong sex drive when the medication’s withdrawn, before (of course) finding the right path to independence and self-confidence in the end–what distinguishes the picture most isn’t him, or the other youngsters in the cast with him (Kelli Garner as the classmate Justin has a crush on, or Chase Offerle as his dismissive kid brother). It’s the rather spectacular array of adult talent that surrounds him. Tilda Swinton and Vincent D’Onofrio play his parents Audrey and Mike, whose self-absorption blind them to his needs. Audrey’s a nurse with a weird crush on the star of a TV cop show (Benjamin Bratt), who takes a job in a celebrity rehab clinic when the guy shows up there for treatment; Mike’s a failed high school football star, now a furniture salesman, who can’t talk to his son about his own disappointments or bear to witness the boy’s successes. Keanu Reeves has a field day sending up his own slacker-dude image as the New Age orthodontist who tries to cure Justin of hid thumbsucking with hypnosis and has a change-of-life experience himself when the kid retaliates. Vince Vaughn’s a hoot as the school debate coach, a guy who’s alternately perceptive and infantile himself. And Bratt, in his single scene, shows a willingness to riff on his “Law and Order” cop shtick.

But while it’s fun to watch all of them, the fact remains that they’re considerably superior to their material. One catches glimmers of complexity and depth in the adult characters, but mostly that’s the result of what the performers bring to the parts rather than what the script does. The effect is certainly enjoyable–especially in the cases of Vaughn and Reeves–but nowhere near as incisive as Mills would have us believe. Much the same can be said of the entire narrative. Perhaps it’s meant to be a satire of the entire genre of parents-watch-your-children exposes, but if so it’s not sharp enough. It winds up seeming just another example of that sort of film, more sophisticated than most to be sure but still locked into their mold.

“Thumbsucker” is less exceptional in technical terms than it is in its casting, looking a bit dank and frayed around the edges. In that respect, too, it’s inferior to “Donnie Darko,” with its luminous, mysterious imagery. Compared to that extraordinary film, this one is less ambitious, less inventive, and ultimately much less satisfying.