Scientists are now looking for the earliest signs of the mysterious disorder as desperate parents hunt for treatments that may improve their children’s lives.

It’s a winter night in Northbrook, Ill., and brothers David and Jason Craven are on the move. They’re watching a “Baby Beethoven” video. They’re bouncing on a mattress in their basement playroom. They’re climbing up their dad’s legs. David, 7, and Jason, 5, with their mops of brown hair, look physically healthy. But both boys are suffering from a devastating developmental disorder: autism. David speaks only about 10 words, still wears diapers at night and sucks on a pacifier. Jason drinks from a baby bottle. Neither one can vocalize his glee as he plays. Neither one can communicate pain or joy in words. Neither one can say “I love you.”

Since their sons were diagnosed, both at the age of 2, Barry and Dana Craven have tried a dizzying array of therapies: neurofeedback, music therapy, swimming with dolphins, social-skills therapy, gluten-free diets, vitamins, anti-anxiety pills and steroids. To reduce the boys’ exposure to environmental chemicals, which the Cravens believe might aggravate their conditions, the couple replaced their carpeting with toxin-free wood floors and bought a special water-purifying system. They even installed a $3,500 in-home sauna, which they think will help remove metals like mercury and arsenic from the boys’ bodies.

Warm and loving parents, the Cravens spent $75,000 on treatments last year alone. “I’m willing to try just about anything if it makes sense,” says Dana.

In the six decades since autism was identified, modern medicine has exploded: antibiotics cure infections, statins ward off heart disease, artificial joints combat osteoarthritis. And yet autism, a vexing brain disorder, remains largely a mystery. Researchers still don’t know what causes it, nor do they know how best to treat a condition that prompts one child to stop speaking and another to memorize movie scripts. With a tenfold spike in numbers over the past 20 years-one in every 166 children is now diagnosed with an Autism Spectrum Disorder (ASD)-researchers, advocacy groups and the government are racing to improve the lives of children and their families, many of them emotionally and financially drained. This year the National Institutes of Health will spend $99 million on autism research, up from $22 million in 1997.