Toni Collette

'The United States of Tara'

Before Showtime’s “The United States of Tara,” Toni Collette had been offered roles in television but could never commit to the idea of playing one character for a long period of time.

Then came Tara, the Kansas wife and mother dealing with dissociative identity disorder. Based on the pilot episode, Collette signed on for seven years.

“I’m more than happy to do that,” Collette says enthusiastically, having just gotten off the phone with the show’s writers as they plan the story arcs for the series’ second season. “The idea of doing a series always seemed so limiting, but this … this is incredibly stimulating. That’s what I want out of the acting experience and it gives it to me in spades.”

Certainly, Collette isn’t lacking for challenges in “Tara,” playing a woman owning at least four alternate personalities, including a pot-smoking teenager, a profane Vietnam-vet truck driver and a June Cleaver-style housewife.

“You know, I’ve been acting for 20 bloody years, and if you do the same thing long enough, you need a little kick up the ass once in a while to make you feel you’re alive,” Collette says. “The fact that I get to play so many characters within one story is like a constant kick up the ass. It makes me feel very alive.”

“Tara,” created by Oscar-winning screenwriter Diablo Cody and sporting Steven Spielberg as an exec producer, won praise for its refusal to treat its title character’s disorder as terrifying, isolating or the butt of easy jokes. Collette so thoroughly disappears inside each “alter” — a term used for each distinct personality — that what could have been seen as a mere actor’s exercise becomes something more universally human.

“It’s lifelike in its complexity,” Collette says. “She has a mental illness, but she’s embraced and loved by her family. Their lives might seem odd to the outside world, but it’s completely normal for them. It’s beautifully dysfunctional.”

What do you like most about your character?

“Which one? I love them all, and for different reasons. They’re all complete individuals, existing as extreme versions of feelings that are repressed within Tara. That’s just fascinating to play, whether it’s T giving the middle finger to the world or Buck, the Harley-driving protector or the anal Alice. They’re all dear to me.”