In his opening statement at a Senate hearing April 17, Senator Tom Harkin (D-IA) noted that the number of diagnosed cases of autism is on the rise, both in the U.S. and in other countries and asked, “Why is this? Are we simply doing a better job of diagnosing autism, or has there been a real increase in the incidence of this disease? What causes autism—are the causes environmental or are the causes genetic? Which therapies work best for children with autism? And what more can the federal government do to help?”

The answer to most of those questions, and particularly to the question of what causes autism, is:“We don’t know,” said the head of the federal government’s autism research at the National Institutes of Health (NIH).

 Dr. Thomas Insel told the hearing that “Much remains unknown about the causes of autism, and identifying both the environmental and genetic underpinnings of autism are critical first steps in bringing the full scientific power of modern neuroscience to bear on this complex set of disorders.”

Defining autism as “a developmental brain disorder with onset by three years of age,” Insel said scientists now believe autism is part of a broader continuum of syndromes known as “autism spectrum disorders” (ASDs) that share deficits in social behavior, abnormal communication, and repetitive behaviors. ASDs range in severity, with “classic” autism being the most disabling, while others, such as Asperger’s syndrome, produce milder symptoms. Currently, Insel said, the prevalence of ASDs (meaning the number of affected individuals at a given point in time, essentially a snapshot) is estimated by the Centers for Disease Control and Prevention (CDC) to be as high as 6.7 children per 1,000.

Research into autism has stepped up in recent years, Insel pointed out, with NIH increasing its funding nearly five-fold to support research across genetic, neuroscience, environmental, and treatment studies. A recently established NIH National Database for Autism Research provides an open-access platform for sharing raw research materials and to facilitate dissemination of research into clinical practice.

On the core question “Can we cure autism?” the jury is still out, Insel said. “There is not a proven biological treatment for the core symptoms of autism,” he said, though “It is generally agreed that early identification and behavioral intervention is beneficial.” And while some medications are useful for some of the symptoms of autism, such as self-injurious behaviors,  “We lack medical treatments for many of the core symptoms, such as social deficits.”

Another federal agency, the Centers for Disease Control and Prevention (CDC), has also increased its presence in autism research, CDC Director Julie Gerberding told the hearing, with the CDC bringing its experience in tracking disease prevalence to bear on the question of whether apparent increases in the autism spectrum disorders are due to better identification or represent a true increase in occurrence. A summary of prevalence data released in February showed the figure of 6.7 eight-year-old children per 1,000 with ASDs, which Gerberding pointed out translates to 1 in 150 children in the communities surveyed.

“CDC recognizes that parents want answers,” Gerberding said. “We share their frustration at not having more answers about the causes and possible cure for the debilitating symptoms of autism and related conditions.” 

Also testifying at the April 17 hearing, advocacy groups asked the Senate Appropriations Subcommittee on Health, which convened the hearing, to increase funding for autism research, saying, “The public health crisis posed by autism requires an extraordinary response. With every child diagnosed with autism costing an estimated $3 million over his or her lifetime, the autism crisis demands a focused, coordinated, and acceptable response by our public health agencies, similar to the federal response to the AIDS crisis in the 1990s.”

A National Institute of Mental Health publication, “Autism Spectrum Disorders,” is available from the NIH website at www.nimh.nih.gov.