What is Autism?
Autism is a general term used to describe a group of complex developmental brain disorders known as Pervasive Developmental Disorders (PDD). The other pervasive developmental disorders are PDD-NOS (Pervasive Developmental Disorder – Not
Otherwise Specified), Asperger’s Syndrome, Rett Syndrome and Childhood Disintegrative Disorder. Many parents and professionals refer to this group as Autism Spectrum Disorders.
How common is Autism?
Today, it is estimated that one in every 110 children is diagnosed with autism, making it more common than childhood cancer, juvenile diabetes and pediatric AIDS combined. An estimated 1.5 million individuals in the U.S. and tens of millions worldwide are affected by autism. Government statistics suggest the prevalence rate of autism is increasing 10-17 percent annually. There is not established explanation for this increase, although improved diagnosis and environmental influences are two reasons often considered. Studies suggest boys are more likely than girls to develop autism and receive the diagnosis three to four times more frequently. Current estimates are that in the United States alone, one out of 70 boys is diagnosed with autism.
What causes Autism?
The simple answer is we don’t know. The vast majority of cases of autism are idiopathic, which means the cause is unknown.
The more complex answer is that just as there are different levels of severity and combinations of symptoms in autism, there are probably multiple causes. The best scientific evidence available to us today points toward a potential for various combinations of factors causing autism – multiple genetic components that may cause autism on their own or possibly when combined with exposure to as yet undetermined environmental factors. Timing of exposure during the child’s development (before, during or after birth) may also play a role in the development or final presentation of the disorder.
A small number of cases can be linked to genetic disorders such as Fragile X, Tuberous Sclerosis, and Angelman’s Syndrome, as well as exposure to environmental agents such as infectious ones (maternal rubella or cytomegalovirus) or chemical ones (thalidomide or valproate) during pregnancy.
There is a growing interest among researchers about the role of the functions and regulation of the immune system in autism – both within the body and the brain. Piecemeal evidence over the past 30 years suggests that autism may involve inflammation in the central nervous system. There is also emerging evidence from animal studies that illustrates how the immune system can influence behaviors related to autism. Autism Speaks is working to extend awareness and investigation of potential immunological issues to researchers outside the field of autism as well as those within the autism research community.
While the definitive cause (or causes) of autism is not yet clear, it is clear that it is not caused by bad parenting. Dr. Leo Kanner, the psychiatrist who first described autism as a unique condition in 1943, believed that it was caused by cold, unloving mothers. Bruno Bettelheim, a renowned professor of child development perpetuated this misinterpretation of autism. Their promotion of the idea that unloving mothers caused their children’s autism created a generation of parents who carried the tremendous burden of guilt for their children’s disability.
In the 1960s and 70s, Dr. Bernard Rimland, the father of a son with autism, who later founded the Autism Society of America and the Autism Research Institute, helped the medical community understand that autism is not caused by cold parents but rather is a biological disorder.