Toni Collette stars in Showtime’s new dramedy about a woman with Dissociative Identity Disorder aptly named “The United States of Tara.” In order to cope with the daily disasters that Tara Gregson (Collette) has encountered since childhood, she has created multiple identities, four to be exact. “T” is the 15-year-old version of herself that oddly gets along swimmingly with Tara’s own 15-year-old daughter, as well as her three other “alters.” The show jumps right into Tara’s life as a stressed mother, gibing about her sexually deviant daughter: “I wish I could just sew her up!” The opening of this new show relies heavily on the interactions and relationships between Tara, her family and her three other “alters,” adding new meaning to the term “dysfunctional family.” Collette gives a bold but real performance, spouting the tongue-in-cheek witticism famous to Oscar-winning screenwriter Diablo Cody. My only quip is that the dialogue tends to flirt too heavily with Cody’s breakthrough debut “Juno,” questioning whether the writing on “Tara” can keep up. When Tara’s daughter says, “I guess I should have let that fertilized egg implant itself in my uterus,” the image of a pregnant Juno slurping her blue slushy is unduly reminiscent and clouds the ability to separate the two stories. John Corbett portrays a doting but weak husband – he fails to bring the same spark and drive that Collette has. Rosemarie DeWitt of “Rachel Getting Married” has a small role as Tara’s sister. Her part seems flat but appropriately so; DeWitt is able to shine despite her brevity, by establishing the awkward relationship she and Tara have. All in all, the show has great potential, and with Spielberg behind it as creator, twists and turns can be expected.Thus far, only Cody stands on shaky ground: the initially promising dialogue can’t catch up to the wit and energy that Collette brings to Tara.