'The Black Balloon' is close to home for Elissa Down

Throughout her childhood, Australian filmmaker Elissa Down was constantly running after her youngest brother, Sean, who is autistic, suffers from attention deficit hyperactivity disorder and is a selective mute.

"He would run down the street in his underpants, and I'd pull him out of toilets in people's homes," says Down. "He played in his pooh. He chewed tampons. And of course, I got frustrated, I got angry. I wished he was normal. I wished I had a different family."

Sean, who is now 26, was the inspiration for her first feature film, "The Black Balloon," which opens Friday.

The heartwarming drama, which won best feature film at the Berlin International Film Festival, in the Generation 14plus section, revolves around Thomas (Rhys Wakefield), a 16-year-old who has moved all around Australia because his father is in the army.

The family has just relocated into a new home in suburban Sydney. And it doesn't take long for his oldest brother, Charlie (Luke Ford), who is autistic, has ADHD and is mute, to cause him embarrassment and draw catty remarks from the neighbors who don't understand autism.

Toni Collette plays their mother, who is dealing with a difficult pregnancy, and model Gemma Ward plays Thomas' beautiful girlfriend, who wants to befriend Charlie.

In real life, Down has three younger brothers, the eldest of whom also is autistic. But she doesn't like to talk much about him or reveal his name, because "he doesn't like to know that people talk about his autism," she says. "He's very intelligent. He is like the 'Rain Man' character."

Brother Sean, she says, was initially diagnosed with ADHD as a child. "It's when they put him on Ritalin they discovered he was autistic, because all of his behaviors slowed down," Down says. "They noticed there was a repetitive nature to it."

Though the movie is semiautobiographical, Down didn't want "Black Balloon" to be a memoir of her life. "It would seem a bit movie of the week," she explains. "We wanted to rework the story and the plot and the characters to fit into a movie structure and to make it entertaining for an audience."

The majority of the response to the film has been overwhelmingly positive, Down says: "Most people love it and laugh and cry." So she was shocked to learn that some moviegoers have walked out angry.