In "Palindromes," the grim new satire by bad boy Todd Solondz, the protagonist, a guileless 13-year-old girl, is played by a confounding array of actors who assume the role at various points with jolting physical discrepancies but an eerie consistency of character. Her name is Aviva, itself a strenuous palindrome, and she is depicted by seven performers: now a chubby little black girl, now a skinny, white redheaded lass; here a morbidly obese black woman, there a gamine young white boy. One of the Avivas is portrayed by Jennifer Jason Leigh, who at 43 and denuded of makeup appears distinctly bedraggled. You have to remind yourself that she is playing a lost girl of 13.

"Palindromes" kicks up a swirl of issues, political, social and emotional, and packages them in fairy tale trappings that are as unsettling as they are surreal. The film, screening Sunday night at the Paramount Theatre during the South by Southwest Film Festival, skewers the hypocrisy of both camps in the abortion debate and depicts the worst instincts of both in extreme and morally suspect acts. An abortion is forced upon Aviva by her mother (Ellen Barkin); an abortion doctor is assassinated by an anti-abortion zealot. With caustic suburban comedies "Welcome to the Dollhouse" (1995) and "Happiness" (1998), Solondz has become one of our toughest satirists, and with "Palindromes" he has made another sophisticated, outré comedy dense with sly, subversive commentary.

After watching the movie, your first question will concern the multicasting of Aviva. Its answer, says Solondz, is entwined in the film's title, which ripples through the story in figurative and literal ways (for example, there is a boy named Otto).

"Palindromes is a word or pattern that instead of developing in different directions it folds in on itself so that the beginning and ending mirror each other," Solondz explains by phone from Los Angeles, where his publicity tour began. His voice is high and whiny, like Woody Allen crossed with a Jewish grandmother.

The unchanging aspects of people, our capabilities and personality, are "palindromic," he says. "For all the metamorphoses we go through in life — we are constantly changing in so many ways — there is also part of ourself that resists change.

"So I have this young girl who, for all her changes and different sizes, shapes and colors, still remains an innocent throughout the traumatic, sordid adventures she has. From beginning to end, there's something constant about her. There's a certain design to this. Each particular girl is assigned to a particular section. The big black woman who plays Aviva during the (church home) segment is Gulliver surrounded by the Lilliputians. There's a storybook quality I wanted to tap into. And when you see Jennifer Jason Leigh at the end, it's as if in a fairy tale when the character comes back from the forest as an old person. It's a face that's lived a life. Emotionally she's been through the wringer, though she is only 13."

Early on, Aviva gets pregnant. (The movie features frequent teen sex.) She wants to keep the baby to the apoplectic disapproval of her mother, prompting Aviva to run away from home into a harrowing picaresque that is by turns creepy (she falls in love with a 40-ish man) and joyful (she joins a Christian rock band made up of severely disabled children, and they're good). It's amusing, frightening, provocative and sad, all of it tinged with Solondz's familiar mean-funny tone that hovers precariously between ironic derision and pointed commentary.

Fans of "Welcome to the Dollhouse" will recognize the character of Mark Wiener, older brother of that film's heroine Dawn Wiener (with whom "Palindromes" begins, if only in name). Mark reappears here visibly aged — and suspected of pedophilia — to dispense the philosophical heart of "Palindromes." His speech is either nihilistic or optimistic, depending on your outlook. Solondz embraces the latter version.

"It's about knowing that one cannot change," the director says. "You have to accept that, say, you are not a genius, that the writing is on the wall. To accept one's limitations, failings and faults can be freeing if one can indeed accept them. The older you get, the closer you get to the end of the trip. Things take on different meanings and values and the understanding of yourself alters. And yet here I am at 45 and in some senses I'm no different than when I was 10."

Solondz's name may safely be lumped with film iconoclasts such as Neil LaBute, Gaspar Nöe, John Waters and Luis Buñuel, whose 1977 movie "That Obscure Object of Desire" employed two actresses to play one woman, a la "Palindromes." The director doesn't want to discuss labels like that, and he declines sharing his personal life or what his next film will be.

He allows that he has "ideas for very marketable, commercial movies, I do. And yet my hands don't listen to me and start writing stories that aren't quite commercial and profitable. There are certain things I am receptive to in the world and where I am in my life that dictates the need to tell certain kinds of stories."

Reminded that an artist's personal life shapes his art and can provide insight into his work, Solondz replies, "Of course it shapes it. It's very tricky reading my movies because everything is so encrypted. It's all part of the process of storytelling. If I were just to detail and use things that literally happened to me it would be a very solipsistic exercise.

"The point is to convert that to something which communicates meaning to others," he says. "If there is a message to my movies, the message is: You are not alone."