<I>Tara</i> writer-producer Diablo Cody Tara writer-producer Diablo Cody

As United States of Tara concludes its first season (Sunday, 10 pm/ET on Showtime), our leading lady is on the cusp of confronting a possible key to her multiple personalities, with her family (mostly) there to support her. Tara's (Toni Collette) decision to go off her medication for Dissociative Identity Disorder (DID) has had significant impact on everyone around her. Each family member seeks closure, while new questions are raised. TVGuide.com caught up with Diablo Cody — the series writer and co-producer with Steven Spielberg — to get her take on the final freshman episode, find out where the show's going next season, which alter was the toughest to tackle — and why it was compared with her Oscar-winning script for Juno. Plus: Check back next week for the scoop on Cody's 90210 appearance with Tori Spelling and more.

TVGuide.com: What was your approach to the first-season finale?
Diablo Cody: [We approach] the mystery that's been unfolding all season: Why does Tara dissociate, what is the trauma that brought on her disorder? It was something that we did in the interest of realism, because the majority of people with DID dissociate because of trauma. And, over the season, we had been talking about the idea of coconsciousness, that her alters are aware of each other, but she's not aware of her alters, but sometimes she is, sometimes she isn't. In the finale, people will have an opportunity to see all the alters trying to inhabit her at once. 

TVGuide.com: How does that play out for her?
Cody: It's chaotic. This season got pretty dark at the end. And it had to; I think given the amount of chaos that's happening in the household. They were definitely at a crossroads. Tara's hospitalization seemed natural. 

TVGuide.com: It seems like all the characters have something to reconcile with Tara before the season's done.
Cody: Definitely. When we saw the pilot, Marshall [Keir Gilchrist] was incredibly close with Tara. And, in the finale, the relationship seems irrevocably broken. So there were a lot of turnarounds... . Everybody changed a lot as a result of the kind of drug holiday experiment that Tara submitted to. [When Tara goes off her medication.]

TVGuide.com: It was also a relief to see the kids acting out a little bit. Marshall finally acting like a teenager [such as when he burns down the shed].
Cody: I wonder how you'd react if you saw your parents making out with your crush. It wouldn't matter how forgiving or how enlightened you were as a teen; you would be pissed. 

TVGuide.com: Max [Tara's husband, played by John Corbett] seems like he's cracking a little bit, especially when he mentions confronting "his own s--t." Will he do that?
Cody: Absolutely. Everybody talks about how supportive Max is and there are no cracks in his perfect, hubby exterior. But Max is cracking on the inside. We're definitely going to see past his game face in the future.

TVGuide.com: Poor guy! Charmaine [Tara's sister, played by Rosemarie DeWitt], meanwhile, has come a long way. Why did you decide to finally find her a man?
Cody: Sometimes we have a tendency to use Charmaine as our whipping post. She's suffered so many humiliations. I actually love her. So, it only seemed fair to let have a triumphant moment.

TVGuide.com: And Kate [Tara's daughter, played by Brie Larson]: She just handled a huge situation [with a love interest and a sexual harassment case] on her own. Where is the finale going to leave her?
Cody: I think Kate is a mystery. She really was a typical adolescent when we started off. And then the whole experience of working outside the house, and dating an older guy. I think she's going to be a lot less predictable. And maybe a little more dangerous. 

TVGuide.com: Tara recently lost its original show runner, Alexa Junge. How is that going to affect things next season?
Cody: The position is filled. Someone is steering the boat... . I'm the creator of the show, and I still feel responsible for the tone. And I think that as long as I'm here, and the writers who were with us last season and believe in the show are here, we're good to go.

TVGuide.com: Where do you see her going from here? Did you know about the second-season pickup when you wrote the finale?
Cody: Yeah, we were still breaking stories... . And I wanted there to be some closure. And I also knew that there needed to be some dramatic changes in the household, and you will see those changes implemented in Season 2. 

TVGuide.com: Were there any aspects of Tara's personality — or alters — that were tougher for you to tackle than others?
Cody: Yeah. I actually think T is a very difficult alter to write, because it can so easily become so broad. "Oh, she's like a sassy teenager. Oh, it's like a Juno redux." Obviously, that isn't what I wanted. I needed T to instead be almost like a really raw expression of Tara's rebellious spirit. 

TVGuide.com: Do you see the alters as metaphorical?
Cody: Definitely. I saw them specifically as metaphors for life as a woman. The definition of femininity used to be so stock. And now it's evolved to a point where women aren't even sure who they're supposed to be to any given moment... . I know that it's been fun for me [to have an alternate name]... . Sometimes it's as easy as a new lipstick. It's weird. If I knew how to survive, I don't think I'd be exorcising my demons in this television show.