Autism is a complex developmental disability that impairs development in social interaction and communication and is often characterized by repetitive behaviors, such as jumping up and down and rocking. In particular, people with autism may be unable to process nonverbal communication, including body language or inflection, causing them to have difficulty understanding differences in tone, such as discerning when someone is joking. People with autism also often have difficulty ascertaining the emotional state of those around them. What is commonly referred to as autism is, more precisely, a group of disorders known as autism spectrum disorders. Autistic disorder is a more severe form of autism, and Asperger syndrome is a milder form. An individual who has symptoms of either of these disorders but does not meet their specific criteria is diagnosed with pervasive developmental disorder not otherwise specified. Other rare, severe disorders that are included in the group of autism spectrum disorders are Rett syndrome and childhood disintegrative disorder. While autism typically is detected during the first 3 years of life, the symptoms, degree, and manner of manifestation range substantially among those with autism. An individual with autism may have some degree of mental retardation or may have above-average intelligence, an expansive vocabulary, or extraordinary abilities in certain areas, such as mathematics or music. Symptoms that children with autism may exhibit include lack of meaningful gestures by 12 months of age, lack of speech by 16 months of age, inability to respond to one’s name, a loss of language or other social skills previously gained, poor eye contact, atypical attachment to a particular toy or object, or inability to use toys or objects. Furthermore, children with autism may not respond like other children. For example, they may seem indifferent, seldom seek comfort, and resist or passively accept affection. Because it is common for individuals with autism to have difficulty regulating their emotions, they may behave inappropriately, disruptively, or even aggressively. They may become frustrated when they are placed in a new environment, and when frustrated may pull their hair, bang their heads, or attack others or themselves. Currently, there is no consensus about the cause of autism. While autism is known to be the result of a neurological disorder that affects the normal functioning of the brain, it is not known precisely what causes the brain disorder or which factors are associated with particular severity levels within the autism spectrum. Theories include genetic components, environmental components, and some combination of genetics and the environment. Experts generally agree that early detection is the best hope of appropriate treatment and best quality of life in later years for those with autism. Most also agree that people with autism generally respond better to highly structured programs tailored to each individual’s particular developmental deficits. To date, most treatment for children with autism has focused on education interventions, which may include speech and language therapy, occupational therapy, and behavior modification. Under the Individuals with Disabilities Education Act (IDEA), states are required to provide eligible children with needed special education and related services. Some physicians may prescribe medications to treat behavioral problems such as aggression and self-injurious behavior; these medications are generally the same medications used to treat similar symptoms in other disorders. It is not known how many people in the United States currently have autism. In 1996, CDC began conducting population-based studies to determine the prevalence of and risk factors for autism, and the agency has reported prevalence rates for children in two communities. These rates were 3.4 and 6.7 per 1,000 children and were higher than previously reported prevalence rates. In addition, in May 2006, CDC reported estimated autism prevalence rates for the period of 2003 to 2004 based on two national surveys, one of which indicated a rate of 5.5 per 1,000 children and the other of which indicated a rate of 5.7 per 1,000 children. Some experts have attributed the reported increase in prevalence to changes in diagnostic criteria, and some have contended that it reflects improvements in early detection. The apparent increase in prevalence, coupled with the lack of a known cause or cure, has sparked concern, particularly among families with affected children. The Children’s Health Act of 2000 required HHS and certain HHS agencies to conduct various activities and programs related to autism. NIH was charged with expanding, intensifying, and coordinating research on autism and awarding grants for autism research centers of excellence. NIH was also directed to establish a program through which tissue samples and genetic materials would be made available for research and to establish a means through which the public could obtain information and provide comments on NIH’s autism-related activities. In addition, the law required CDC to establish an autism and developmental disabilities surveillance program through regional centers of excellence to collect and analyze information and coordinate research related to the epidemiology of autism. The law also required the establishment of an interagency autism coordinating committee to coordinate efforts within HHS. Many of these activities have been funded through lump sum appropriations to NIH and CDC, and the Congress has generally not appropriated funds specifically for autism projects and activities. NIH and CDC support an array of autism activities, and officials from both agencies told us that their funding of autism activities increased from fiscal year 2000 to fiscal year 2005. NIH’s efforts include research on determining the causes of autism, improving the diagnosis and treatment of autism, and improving the delivery of autism-related services. CDC supports surveillance activities, including tracking the characteristics and prevalence of autism. CDC’s surveillance programs have relied on information from multiple sources, including student education records, to obtain a complete and unduplicated count of the number of children with autism. However, CDC officials believe a 2003 change in Education’s interpretation of the federal law governing the privacy of education records has hindered CDC’s ability to continue to use this methodology. HHS and Education were required to submit a report to congressional committees in June 2005 identifying how to overcome the challenges CDC faces in using education records to conduct surveillance; as of June 2006, the agencies had not agreed on options for overcoming these challenges and had not completed the report. NIH’s estimated funding of autism research increased from about $51.5 million in fiscal year 2000 to about $101.6 million in fiscal year 2005. CDC’s total funding of autism activities increased from about $2.1 million to about $16.7 million during the same period. NIH has undertaken research activities that focus on determining the causes of autism, improving the diagnosis and treatment of autism, and improving the provision of services related to autism. (See app. II for information on selected NIH autism activities.) Many of these activities were developed to respond to the Children’s Health Act’s general requirement that NIH expand, intensify, and coordinate its autism research activities and to the act’s specific requirements, such as that NIH establish centers for conducting research on autism and establish a program through which tissue samples and genetic materials would be available for research. NIH research that focuses on determining the causes of autism includes efforts to identify genes that increase susceptibility to the disorder and efforts to ascertain the role of environmental exposures. For example, NIH’s National Institute of Environmental Health Sciences, in partnership with the Environmental Protection Agency, supports a national network of centers to examine the effect of environmental exposures on children’s health. Of the 11 centers this program supports, 2 centers conduct research on environmental causes of autism and perform clinical evaluations of children with autism. NIH also conducts research evaluating specific treatments for the symptoms associated with autism. Several federal officials and advocacy association representatives told us that there are not enough evidence- based treatments for people with autism, and NIH has several activities to help develop such treatments. For example, in response to the increasing use of medications to treat symptoms of autism, the National Institute of Mental Health (NIMH) in 1997 established a network of research sites to study the use of psychotropic drugs in the treatment of autism. In 2002, the network was renewed and expanded to include psychosocial and behavioral interventions. Support for the research is designated specifically for evaluating treatments for autism, and the networks are intended to be a national resource that will expedite clinical trials in children. For example, one study found that methylphenidate—a treatment for attention deficit/hyperactivity disorder—was often effective for improving inattention, hyperactivity, impulsivity, and distractibility in children with autism who participated in the study. NIH’s largest investment in autism research is through its support of networks of research centers, such as the Collaborative Programs of Excellence in Autism (CPEA), consisting of nine centers, and the Studies to Advance Autism Research and Treatment (STAART), consisting of eight centers and a data coordination center. NIH’s National Institute of Child Health and Human Development and National Institute on Deafness and Other Communication Disorders established the CPEA network in 1997; in 2002, they renewed the network for an additional 5 years and in 2003 expanded it to include a data coordinating center. NIH began the STAART program in 2001 in response to the Children’s Health Act. Some centers participate in both networks, which have similar purposes in conducting research on the causes, diagnosis, early detection, and treatment of autism. Unlike the CPEA network, the STAART network requires that each center have at least one treatment project. NIH officials told us the institutes are planning to unify the STAART centers and CPEAs into a new network—Autism Centers of Excellence—in an effort to improve coordination of NIH-sponsored efforts, avoid duplication, and maximize the efficient use of resources. NIH also supports programs that provide research resources, such as genetic materials and tissue samples, to scientists working on autism. For example, NIH’s National Institute of Neurological Disorders and Stroke and NIMH are providing support to the Harvard Brain Tissue Resource Center to increase the collection of brains from individuals diagnosed with autism, which is expected to facilitate neurobiological research on autism.