I also found this one of the more enjoyable films of the year and I loved the whole cast, which includes some surprise choices such as Swinton, Vaughan, and Bratt, whom you wouldn't expect to see together in the same movie. Good point about the range of addictions.

From my website

Thumbnail Review of 'Thumbsucker'

Thumbsucker, a first-time film by Mike Mills, is a successful coming-of-age story becuse of strong, restrained acting and a subtle attitude. Justin Cobb (Lou Pucci) is a slightly androgynous seventeen-year-old in an Oregon suburb who still sucks his thumb. His mom Audrey (Tilda Swinton) is shocked and his dad Jack (Vincent D'Onofrio) is disapproving; and his orthodontist Perry (Keanu Reeves) -- who fancies himself as a consciousness-raising therapist, tries to cure him with hypnosis evoking his "power animal" and making the thumb taste to him like Echinacea.

Perry's cure works but Justin is going nuts in the absence of his habit and his girlfriend Rebecca (Kelli Garner), an environmental activist, drops hiim because he can't be "open" with her and he drops out of the debating team. Then a school counsellor suggests his problem is ADD and Ritalin pumps him up into the star debater who wins the local championship.

Everything is lightly satiric but believable. The debate scenes are interesting and well done. Mr. Geary (Vince Vaughan), the debate coach, becomes Justin's new mentor. Vaughan, who's known for extreme performances, is restrained. Audrey is fascinated by the star of a TV series, Matt Schramm (Benjamin Bratt, funny but, again, restrained in a brief cameo), who turns out to have a drug problem. She becomes a counselor at a celebrity rehab clinic and comes into contact with him. Justin, meanwhile, has turned into a bit of a monster and quits Ritalin, realizing it's just speed. Justin's little brother Joel (Chase Offerle) injects pungent comments and has to play the normal kid in the family. Rebecca comes back into the picture and is now a stoner -- this is one of the ways Thumbsucker, which is based on a novel by Walter Kern, convincingly chronicles the rapid changes and seeming reversals high schoolers can go through.

Adults change too. Jack (D'Onofrio), who before his marriage to Audrey gave up hopes of pro-football due to a knee injury, has a dad's usual difficulty communicating with his son, but he maintains intimacy. Audrey realizes a dream by becoming a counsellor; Perry drops alll his visionary hype and gets more real with himself.

Thumbsucker consistently avoids obvious climaxes and easy laughs. There isn't a moment when the scenes are not smart and fresh. Justin comes down to earth, but his high-flying period led to a successful college application and he heads off to NYU. The trajectory may seem conventional but there have been many quietly choice moments of subtle acting and drole but true observation along the way.

[color=dark gray]Chris Knipp.[/color]