More than $1 billion has been spent over the past decade researching autism. In some ways, the search for its causes looks like a long-running fishing expedition, with a focus on everything from genetics to the age of the father, the weight of the mother, and how close a child lives to a freeway.
That perception may soon change. Some in the field say they are seeing the beginning of a wave of scientific reports that should strengthen some theories, jettison others and perhaps even herald new drugs. “I do think over the next three to five years we’ll be able to paint a much clearer picture of how genes and environmental factors combine” to cause autism, said Geraldine Dawson, a psychologist who is chief science officer for the advocacy group Autism Speaks.
The effort has been infused with new urgency by a recent federal report that found autism disorders are far more common than was previously understood, affecting 1 in 88 U.S. children. Better diagnosis is largely responsible for the new estimate, but health officials said there may actually be more cases of autism, too. If autism’s causes remain a mystery, “you’re not going to be able to stop this increase,” said Irva Hertz-Picciotto, a researcher at the University of California, Davis who is leading a closely watched study into what sparks autism disorders.
In the past week, a spate of studies released during National Autism Awareness Month has offered tantalizing new information about potential causes. Research published in the journal Nature widened the understanding of the genetic roots of some cases and confirmed the elevated risks for children with older fathers. Another study, released online Monday in Pediatrics, suggested maternal obesity may play a role.
To be sure, finding the causes of autism — an umbrella term for a variety of disorders that delay children socially or intellectually — remains daunting. The causes are believed to be complicated, and not necessarily the same for each child. Some liken autism to cancer — a small word for a wide range of illnesses. In many cases, autism can be blamed on both genetic problems that load the gun and other factors that pull the trigger.