Autism was first identified in 1943 by Dr. Leo Kanner of Johns Hopkins Hospital. At the same time, a German scientist, Dr. Hans Asperger, described a milder form of the disorder that is now known as Asperger Syndrome. These two disorders are listed in the DSM IV (Diagnostic and Statistical Manual of Mental Disorders) as two of the five developmental disorders that fall under the autism spectrum disorders. The others are Rett Syndrome, PDD NOS (Pervasive Developmental Disorder), and Childhood Disintegrative Disorder.
These disorders are characterized, in varying degrees, by difficulties in social interaction, verbal and nonverbal communication and repetitive behaviors. With the May 2013 publication of the DSM-5 diagnostic manual, all autism disorders were merged into one umbrella diagnosis of ASD. Previously, they were recognized as distinct subtypes, including autistic disorder, childhood disintegrative disorder, pervasive developmental disorder-not otherwise specified (PDD-NOS) and Asperger syndrome.
ASD can be associated with intellectual disability, difficulties in motor coordination and attention and physical health issues such as sleep and gastrointestinal disturbances. Some persons with ASD excel in visual skills, music, math and art.
Autism appears to have its roots in very early brain development. However, the most obvious signs of autism and symptoms of autism tend to emerge between 2 and 3 years of age. Autism Speaks continues to fund research on effective methods for earlier diagnosis, as early intervention with proven behavioral therapies can improve outcomes. Increasing autism awareness is a key aspect of this work and one in which our families and volunteers play an invaluable role.
Autism statistics from the U.S. Centers for Disease Control and Prevention (CDC) identify around 1 in 68 children as on the autism spectrum–a ten-fold increase in prevalence in 40 years. Careful research shows that this increase is only partly explained by improved diagnosis and awareness. Studies also show that autism is four to five times more common among boys than girls. An estimated 1 out of 42 boys and 1 in 189 girls are diagnosed with autism.
ASD affects over 3 million individuals in the U.S. and tens of millions worldwide. Moreover, government autism statistics suggest that prevalence rates have increased 10 to 17 percent annually in recent years. There is no established explanation for this continuing increase, although improved diagnosis and environmental influences are two reasons often considered.
Not long ago, the answer to this question would have been “we have no idea.” Research is now delivering the answers. First and foremost, we now know that there is no one cause of autism just as there is no one type of autism. Over the last five years, scientists have identified a number of rare gene changes, or mutations, associated with autism. A small number of these are sufficient to cause autism by themselves. Most cases of autism, however, appear to be caused by a combination of autism risk genes and environmental factors influencing early brain development.
In the presence of a genetic predisposition to autism, a number of nongenetic, or “environmental,” stresses appear to further increase a child’s risk. The clearest evidence of these autism risk factors involves events before and during birth. They include advanced parental age at time of conception (both mom and dad), maternal illness during pregnancy and certain difficulties during birth, particularly those involving periods of oxygen deprivation to the baby’s brain. It is important to keep in mind that these factors, by themselves, do not cause autism. Rather, in combination with genetic risk factors, they appear to modestly increase risk.
A growing body of research suggests that a woman can reduce her risk of having a child with autism by taking prenatal vitamins containing folic acid and/or eating a diet rich in folic acid (at least 600 mcg a day) during the months before and after conception.
Increasingly, researchers are looking at the role of the immune system in autism. Autism Speaks is working to increase awareness and investigation of these and other issues, where further research has the potential to improve the lives of those who struggle with autism.
Each individual with autism is unique. Many of those on the autism spectrum have exceptional abilities in visual skills, music and academic skills. About 40 percent have average to above average intellectual abilities. Indeed, many persons on the spectrum take deserved pride in their distinctive abilities and “atypical” ways of viewing the world. Others with autism have significant disability and are unable to live independently. About 25 percent of individuals with ASD are nonverbal but can learn to communicate using other means. Autism Speaks’ mission is to improve the lives of all those on the autism spectrum. For some, this means the development and delivery of more effective treatments that can address significant challenges in communication and physical health. For others, it means increasing acceptance, respect and support.
Research suggests that the development of autism is rooted in very early brain development. However, in most cases, no one cause can be identified. Research has identified several genes that can cause autism in and of themselves. These account for about 15 percent of cases of autism spectrum disorders. Research has identified more than 100 genes or gene changes (mutations) that increase the risk that a child will develop autism. In most cases, genetics alone can't distinguish why one person has autism and another does not. Gene-environment interactions appear to be at play. When scientists use the term “environment,” they are referring to a wide range of nongenetic factors. Those most associated with increased autism risk include advanced parental age at time of conception and prematurity with very low birth weight. Other possible environmental risk factors include maternal diabetes or infection during pregnancy and certain birth complications, particularly those that may involve oxygen deprivation to a baby’s brain. Autism Speaks continues to fund a wealth of studies on the causes of autism, including research on gene-environment interactions that may increase autism risk. You can explore these and other studies using our Grant Search.
Many studies have been conducted to determine if a link exists between immunization and increased prevalence of autism, with particular attention to the measles-mumps-rubella (MMR) vaccine and vaccines containing the preservative thimerosal. These studies have found no link between vaccines and autism. We strongly encourage parents to have their children vaccinated, because this will protect them against serious diseases. It remains possible that, in rare cases, immunization might trigger the onset of autism symptoms in a child with an underlying medical or genetic condition. Autism Speaks is funding studies on the underlying biology of autism, including studies to better understand medical and genetic conditions associated with autism.
We recognize that some parents may still have concerns about vaccines, especially those parents who already have a child or relative with an autism spectrum disorder. Because parents and guardians differ in their sensitivity and concern about this issue, we urge them to find a pediatrician or other health practitioner who will partner with them to consider their concerns and help them ensure the optimal well-being of their child. Establishing open communication and trust with a physician who understands each child and his or her family is the best strategy for keeping a child healthy.
Though autism cannot be definitively diagnosed until around 18 to 24 months, research shows that children as young as 8 to 12 months may exhibit early signs. Parents should look for symptoms such as no back-and-forth sharing of sounds, smiles or other facial expressions by 9 months; no babbling or back-and-forth gestures (e.g. pointing) by 12 months; or any loss of babbling, speech or social skills at any age. For more information, please see our Signs and Symptoms page and the “Developmental Milestones” section of our Video Glossary.
Don't wait. Talk to your doctor or contact your state’s Early Intervention Services department about getting your child screened for autism. (For more information and public resources, see the Early Intervention section of our 100 Day Tool Kit, or view our other Tool Kits here.) Research has consistently shown that early diagnosis and intervention offer the best chance for improving function and maximizing a child’s progress and outcomes.
In addition to the Early Intervention Services mentioned above, it’s important to make sure your child has a knowledgeable and reputable healthcare team. This means finding doctors, therapists, psychologists and
teachers who understand and have experience with autism and can respond to his shifting needs appropriately.
The Autism Speaks Autism Treatment Network (ATN) is a ground-breaking network of hospitals, physicians, researchers and families at 17 locations across the United States and Canada. ATN clinicians work together to develop the most effective approach to medical care for children and adolescents affected by autism. The ATN’s aim is to provide comprehensive, high-quality care by teams of healthcare professionals who understand autism spectrum disorders and excel at treating associated medical conditions including the sleep disturbances and gastrointestinal problems that can vex children with ASD and their families. You can locate your nearest ATN center here.
Many persons with Asperger syndrome or other high-functioning forms of autism never received a diagnosis as a child. They may be diagnosed as adults when seeking help for related problems at work or in their social lives. Consider asking your physician for a referral to an appropriate specialist. Professionals qualified to make an adult autism diagnosis include licensed clinical psychologists, neurologists and psychiatrists. Some nurse practitioners, social workers and master’s level psychologists likewise have the expertise to diagnose autism in adults.
For adults, an autism diagnosis may bring relief in terms of an explanation for their lifelong struggles. For parents, the first months after learning that their child has a developmental disorder can be emotional, confusing and challenging. For this reason, Autism Speaks has developed the 100 Day Tool Kit, to help families navigate the often-tumultuous first 100 days after a child’s diagnosis. You can find all of our tool kits here.
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