A 2008 survey of the scientific literature reported that between 3 percent and 25 percent of children diagnosed with autism eventually recover, and a study this year at the University of Connecticut rigorously tested 34 children who had been diagnosed with autism as toddlers and are now largely free of symptoms.
Rocco's story is typical in one other way, though. Most experts say that the earlier autistic children can begin therapy, the more progress they will make.
One of the best validated therapy techniques is the Early Start Denver Model, developed by Sally Rogers, now at the University of California, Davis, and Geraldine Dawson, who recently left her post as chief science officer at Autism Speaks and is now at Duke University.
In a 2009 study of their model, which features intensive one-on-one therapy in a naturalistic setting several hours a week, children in that group showed significantly greater gains in language and thinking ability over a two-year period than autistic children in a control group. In a follow-up study last year, researchers found the Early Start group also showed more brain activation when viewing faces -- a sign of responding to social cues -- while the control group showed more brain activity when viewing objects.
In an interview earlier this year, Ms. Rogers said the key to their approach is providing therapy in everyday settings the children would already be involved in.
In older behavioral therapy, she said, "if you wanted to teach the child the names of objects, you would figure out what that child is motivated for -- food, drinks -- and you'd put out a shoe and say 'Where's shoe?' and you'd give them a treat when they touched the shoe."
In the Early Start approach, "kids come in to therapy every day and when they take off their shoes, I would say, 'Where's that foot?' or 'Give me shoe?' " And at the end of the session I would say, 'Get Jason's sock; get Sally's shoe.'