The CDC data indicate "a major public health crisis" and a need for more money to fund autism research and programs for children and adults with the disorder, said Geraldine Dawson, chief science adviser for the advocacy group Autism Speaks.
"That means that 750,000 children are now estimated to have an autism spectrum disorder, and those children will be growing up to be adults and will need services throughout their life spans," she said.
She pointed out a 2007 study from the Harvard School of Public Health that found the nation spends $35 billion each year to care for people with autism. And yet, in 2008, just $177 million was spent on research.
"Without answers to understand why we are seeing this increase, we are not going to be able to develop ways of preventing or more effectively treating autism," Dawson said.
In addition, researchers need more families to participate in studies to nail down autism's causes, said Goldstein. About 10 percent of all affected families participate in research, he said. As far as genetic research goes, just a fraction of the genes that might be responsible for autism have been identified, Dawson said. And scientists are still mystified by what environmental causes might play a role.
"We still need to identify more of the genes, and more of the exposures," he said. "Successes in childhood cancer came when nearly every child with cancer was involved in a clinical trial. That is not the case with autism. We really need to encourage families to get that participation rate way up."
Complicating matters are the likely various subtypes of autism with different causes, said Li-Ching Lee, a psychiatric epidemiologist at Johns Hopkins Bloomberg School of Public Health, who gathered the Maryland data for the CDC report.
The figures are essential for policymakers as they consider research funding and expanded programs for children and adults with the disorder, said Lee, who is also investigating prevalence of autism in China and Taiwan. "This can give us a guide as we develop future studies."