Health officials say the new information doesn't indicate more children have autism, but shows that doctors are more frequently diagnosing the disorder.
The statistics can be demoralizing, but a recent autism breakthrough is music to one Redmond child's ears.
When Sasha Chigirinskiy began occupational therapy he was easily irritable and inattentive.
"He'd be screaming, crying, refusing to participate," said occupational therapist Doreen Hunt.
Nearly two years later, the autistic 5-year-old who couldn't catch a ball or balance on a scooter is a different kid.
"Little things improved so much during last two years. He really believes in his body," said Sasha's father, Eugene.
The change started when Sasha put on a pair of headphones and heard the soothing sounds of Mozart. The music is part of ILS, or Integrated Listening Systems. The theory is that different classical or orchestral songs develop different parts of the brain.
"The music is specifically designed and altered in a sound studio to give him both his body and his brain the kind of sound input he needs," Hunt said.
Performing simple activities while listening to low frequencies found in Gregorian chants and cellos improves balance, coordination and core strength. Low frequencies are filtered out and higher frequencies come in to improve communication and attention.
"He can communicate when he's mad instead of screaming, yelling and running away," Hunt said.
Headphone vibrations send information through the kindergartener's bones to muscle and inner ear for balance.
Sasha's struggles are now fewer.
"Two years ago he couldn't even draw the line," Eugene said. "Now he can actually write letters. He can write his name, which is great."
Before the music, Sasha's parents feared for his future. Today, they're singing a different tune.
"This is great. Actually, this is hope," Eugene said.
Hunt said ILS uses mostly Mozart because the compositions are "well rounded," with highs and lows that even when filtered still sound like music.