With a subject as specific as sex addiction, comparisons to 2011's "Shame" are inevitable. That dark drama was a deep-probe character study, intensely focused on a man consumed by his cravings. By contrast, "Thanks for Sharing" is an ensemble piece juggling humour with sober observation of three men intent on overcoming their dependence on the pleasures of the flesh. Making a technically polished directing debut, screenwriter Stuart Blumberg ("The Kids Are All Right") has in essence crafted the date-night version of the sexaholic's confessional.

While it doesn't crawl under the skin the way "Shame" did, this serio-comedy, with its name cast, offers a glossy portrait of New York as a playground of visual stimuli. Captured in crisp advertising imagery and singing colours by cinematographer Yaron Orbach, it's a metropolitan catwalk, a promo-reel for romance and desire.

All of that keeps "Thanks for Sharing watchable and mildly entertaining, even if it's 15-20 minutes too long. What stops the film from being more satisfying, however, is a problem with the way the central character's arc takes shape, and a key piece of miscasting. Bashing Gwyneth Paltrow has become a tired, easy sport that anyone can play. But her preening performance in an inconsistently drawn role here is a major intrusion.

A smart, soulful environmental consultant celebrating five years in recovery, Marc Ruffalo's Adam is carefully set up to give the film a core of emotional integrity. When his sponsor, Mike (Tim Robbins), insists it's time for him to bite the bullet and start dating again, he conveniently meets Paltrow's Phoebe at a foodie bug-tasting evening. She's a cancer survivor and fitness fanatic whose previous boyfriend's alcoholism gave her an aversion to addicts, which means Adam predictably stalls before sharing details of his recovery.

In a staggeringly miscalculated scene, Phoebe processes the unsettling news and then gives the relationship another shot by stripping down to fetish lingerie and demonstrating her lap-dancing skills on a stunned Adam. While this reads as insensitive, sadistic, stupid or all three, Blumberg and co-scripter Matt Winston justify the behaviour by having Phoebe say: "I'm a very sexual person. I need to express that side of me." The queen of mixed signals, she's a phoney character and a too-transparent catalyst for Adam's inevitable fall from the wagon.

This shortchanges Ruffalo, who gives a typically sensitive performance, both in his monastic adherence to the vigilant rules of sobriety and his wounded admission of defeat. But it's hard to remain invested in whether or not Adam and Phoebe work things out. He deserves better.

The film has more nuance and credibility in its secondary strands. One concerns the stubbornness of Mike, an aphorism-spouting addiction group elder statesman, who has little faith in the claim that his ex-junkie son Danny (Patrick Fugit) is now clean and eager to atone for his missteps. And Danny is still waiting for Mike's contrition for his drunken toxicity during the boy's childhood.

Also getting considerable attention is the progress of Neil (Josh Gad), a chubby young ER medic doing court-ordered SAA time for nonconsensual frottage. Unrepentant at first, and reluctant to adopt the austerity measures required by the program -- no television, no Internet, no masturbation, no subways -- Neil alienates his designated sponsor, Adam. But when he's fired as a result of his illness, he gets serious. Help comes, paradoxically, from the lone female in the group, Dede (Alecia Moore), a tattooed tough girl.

A breakout star of "The Book of Mormon" on Broadway, Gad does the film's comedic heavy lifting, much of it demeaning physical gags and scenes with his suffocating Jewish mother (Carol Kane). But it's in the sweet blossoming of Neil's loving yet platonic friendship with Dede, and their mutual support, that Gad's work resonates most. Better known as pop-punkster Pink, Moore proves a capable actor and a relaxed, enormously likable screen presence.