What is Autism?
This information adapted from the Autism Society of America website.
Autism is a complex developmental disability that typically appears during the first two
years of life and is the result of a neurological disorder that affects the functioning of the
brain, impacting development in the areas of social interaction and communication skills.
Both children and adults on the autism spectrum typically show difficulties in verbal and
non-verbal communication, social interactions, and leisure or play activities.
Autism is one of five disorders that fall under the umbrella of Pervasive Developmental
Disorders (PDD), a category of neurological disorders characterized by “severe and
pervasive impairment in several areas of development.”
The five disorders under PDD are:
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Autism Disorder
Asperger Syndrome Disorder
Childhood Disintegrative Disorder(CDD)
Rett Syndrome Disorder
PDD-Not Otherwise Specified (PDD_NOS)
is based upon the Diagnostic and Statistical Manual of Mental Disorders - Fourth
Edition (DSM-IV) (American Psychiatric Association, Washington DC, 1994), and is the
main diagnostic reference of mental health professionals in the United States.
According to the DSM-IV, the term "PDD" is not a specific diagnosis, but an umbrella
term under which the specific diagnoses are defined.
Prevalence of Autism
Autism is the most common of the Pervasive Developmental Disorders, affecting an
estimated 1 in 150 births (Centers for Disease Control Prevention, 2007). Roughly
translated, this means as many as 1.5 million Americans today are believed to have some
form of autism. And this number is on the rise.
Based on statistics from the U.S. Department of Education and other governmental
agencies, autism is growing at a startling rate of 10-17 percent per year. At this rate, the
Autism Society estimates that the prevalence of autism could reach 4 million Americans
in the next decade.
Autism knows no racial, ethnic, or social boundaries; family income levels; lifestyle
choices; or educational levels, and can affect any family and any child.
And although the overall incidence of autism is consistent around the globe, it is four
times more prevalent in boys than in girls.
For more information contact www.autism-society.org or 1-800-328-8476
Autistic Disorder
Autism is a complex developmental disorder often referred to as Classic Autism. Autism
affects people differently; some characteristics affect a person's ability to communicate,
or form relationships with others, and respond appropriately to the environment. Some
people with autistic disorder are high functioning, with speech and intelligence intact.
Others may be nonverbal and/or have a cognitive disability or mental retardation.
Asperger Syndrome
Asperger disorder, sometimes referred to as Asperger syndrome, is a neurobiological
disorder. In contrast to autistic disorder, individuals with Asperger disorder do not have a
delay in spoken language development. However, they can have serious deficits in
socialization, communication, cognition and sensation. Like classic autism, Asperger is a
neurological disorder what affects behaviors such as obsessive, repetitive routines and
preoccupations with a particular subject matter.
Childhood Disintegrative Disorder
Children with childhood disintegrative disorder develop normally for a relatively
prolonged period (usually 2 to 4 years) before developing a condition that resembles
autistic disorder. Typically language, interest in the social environment, and often
toileting and self-care abilities are lost, and there may be a general loss of interest in the
environment.
Rett Syndrome
Rett disorder is a childhood neurodevelopment disorder characterized by normal early
development followed by loss of purposeful use of the hands, distinctive hand
movements, slowed brain and head growth, gait abnormalities, seizures, and mental
retardation. Rett disorder is genetic in origin, and is among the most common genetic
cause of profound intellectual and physical disability in mostly girls exclusively.
Rett disorder occurs more commonly in less than 1 in 10,000 female births. Individuals
with Rett disorder develop normally until 6 to 18 months of age followed by a
developmental regression. In 1999, a gene for Rett disorder was identified by NICHDsupported researchers. The course of Rett syndrome, including the age of onset and the
severity of symptoms, varies from child to child. Hypotonia (loss of muscle tone) is
usually the first symptom. As the syndrome progresses, the child loses purposeful use of
her hands and the ability to speak. Other early symptoms may include problems crawling
or walking and diminished eye contact. Another symptom, apraxia -the inability to
perform motor functions — is perhaps the most severely disabling feature of Rett
syndrome, interfering with every body movement, including eye gaze and speech.
Individuals with Rett syndrome often exhibit autistic-like behaviors in the early stages.
Other symptoms may include toe walking; sleep problems; wide-based gait; teeth
grinding and difficulty chewing; slowed growth; seizures; cognitive disabilities; and
breathing difficulties while awake such as hyperventilation, apnea (breath holding), and
air swallowing.
Pervasive Developmental Disorder Not Otherwise Specified (PDD/NOS)
PDD/NOS is a diagnosis often considered for children who show some signs of autistic
disorder, but who do not meet the specific diagnostic criteria for the other Pervasive
Developmental Disorders. (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, 1994)
For more information contact www.autism-society.org or 1-800-328-8476