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.
