By Ken Tucker
Updated January 21, 2009 at 05:00 AM EST
Jordin Althaus/Showtime

I guess it’s a measure of how well-done United States of Tara is that I kept worrying about the emotional health of the two children being raised by Toni Collette’s Tara, who’s afflicted with a multiple personality disorder. Tara, a Kansas interior designer, ?responds to pressures in her life by becoming prissy homebody Alice, randy teen T,? or male horndog Buck. Collette does this through sheer bravura acting and the appropriate clothes — it’s stunning work. So is the writing by Diablo Cody (Juno, and EW columnist, of course), whose gift for delineating both plot and character through vivid comic dialogue suggests an ambition to be the heir to great movie writers like Preston Sturges (Sullivan’s Travels) and Ernest Lehman (Sabrina).

Tara’s household consists of husband Max (Sex and the City‘s John Corbett) and teens Kate (Brie Larson) and Marshall (Keir Gilchrist), who says to his mother?half-proudly, half-woefully?”Because of you, we get to be interesting.” If you can buy the series’ outlandish premise that this family can coexist, perhaps even thrive, without any assurance of who Tara may turn into at any moment, then you’re in for an odd, funny, moving experience. The fragile kids here are so vividly portrayed, my pleasure was complicated by the idea that Tara-the-show is transfixing, but Tara-the-mom really ought to go back on her mood-steadying meds. B+