When the film "Thanks for Sharing" opens, we see the always studly Mark Ruffalo praying on his knees bedside, then eating a bowl of cereal by himself in his nicely furnished New York apartment. Why would a guy this good looking be all by himself? Recent break up? Bachelor by choice? No and no. Turns out, Ruffalo's character, Adam, is in a self-imposed state of singledom. He's been "sober" for five years, he reveals, but it isn't alcohol that's his addiction, it's sex.

"Thanks for Sharing," the directorial debut by Stuart Blumberg, one of the writers behind "The Kids Are All Right," which also starred Ruffalo, provides the same tempo and tone as "Kids," which was nominated for an Oscar in 2011. It's a deep dive into the lives of four characters that have been forced, for some reason or another, into a Sex Addicts Anonymous 12-step program – some went willingly after hitting rock bottom, others were court ordered to participate.

The dimension of the characters, especially the 12-steppers, is what keeps Blumberg's script (co-written with Matt Winston) from getting too preachy. There's Josh ("Book of Mormon") Gad, a slovenly emergency room doctor named Neil whose ethics are less than above board because of his sex addiction. The last straw is when his female boss discovers a wrist camera that he has been using to capture video of a shot up the chief of staff's dress. His relationship with his mother, however, is downright creepy and somewhat unnecessary as it brevity doesn't further any of the plotline.

Tim Robbins plays the wise sage of the group, who spouts Alcoholic Anonymous fortune cookie phrases, and is the model sponsor for the addicts who need help staying on the wagon. He's the reformed addict-alcoholic whose wife, played by Joely Richardson, has stuck by him despite his passing Hepatitis C to her and whose relationship with his alcoholic and drug addicted son (Patrick Fugit) is always on the outs.

 Alecia Moore (a.k.a. rocker Pink) makes an impressive acting debut as a hairdresser whose sexual appetite is rampant and who befriends an unlikely guy pal in Neil (Gad).

When Adam (Ruffalo) meets Phoebe (Gwyneth Paltrow) almost midway into the film, yet another cog enters into this already complicated wheel. She's a breast cancer survivor who has had relationships with addicts in the past, and doesn't care for a repeat performance. Her character is probably the thinnest drawn and a scene where she dons lingerie a la Frederic's of Hollywood and attempts to perform a lap dance is laughable in its non believability. She utters the line, "I'm a very sexual person," but Paltrow lacks any real exuding of sexuality up to that point. She's more peaches and cream, than whipped cream.

Yet, each of the characters, even hers, has a likeability factor and their struggles are true to heart. Blumberg has a knack for these character studies as he proved so well in "Kids."

"Thanks for Sharing" has its share of formulaic set ups, but it's still worth raising a glass in its honest portrayal of the human struggle of addiction in any form.