What are spectrum disorders?
Autism spectrum disorders (ASD), also known as pervasive
developmental disorders (PDD), are conditions with various levels
of impaired communication skills, impaired social skills, and
repetitive behaviors or interests. Sensory issues are also very
common in the autism spectrum disorders. These disorders are
neither diseases nor mental illnesses. Pervasive developmental
disorders are a type of developmental disorder, as the name
implies.
There are five disorders included in autism spectrum disorders:
autism (sometimes called Kanner's Syndrome), Asperger's Syndrome
(AS), pervasive developmental disorder not otherwise specified
(PDD-NOS), Rett Syndrome, and childhood disintegrative disorder
(also known as Heller's Syndrome). Autism or autistic disorder is
the most well-known of the PDDs. Characteristics of autism are
impaired social skills, impaired communication skills, repetitive
behaviors or interests, and abnormal or delayed skills in social
interaction, language use, or play. It usually becomes apparent by
age three. It is more often diagnosed in males than in females.
Rett Syndrome is the least common diagnosis. Most people with
Rett Syndrome are female. They seem to have normal prenatal
development and continue to develop apparently normally for the
first five to 18 months. After that period, head growth
decelerates, hand skills decline, social engagement with others
disappears, walking appears uncoordinated, language is severely
impaired, and psychomotor skills are severely impaired. The child
regresses. Children who had been able to talk, stop. Children who
previously enjoyed social contact now start pulling away from it.
Most of those with Rett Syndrome end up in wheelchairs. Childhood
disintegrative disorder is another rare autism spectrum disorder.
It is diagnosed using norm-referenced tests, not parental accounts.
In can be misdiagnosed as late-onset autism. These children develop
apparently normally for the first two years. Then, between the ages
of three and four, they have a significant loss of skills in at
least two of the following areas over the next few years:
communication skills, social skills, motor skills, play skills, and
control of bowel and/or bladder functions. They also engage in
repetitive behaviors or interests. It can also be accompanied by
seizures and extremely low IQ.
Asperger's Syndrome also involves impaired social skills and
repetitive behaviors or interests, but no clinically significant
delay in cognitive development and language development (except
socially). This condition was once labeled as infantile
schizophrenia.
Pervasive developmental disorder - not otherwise specified is
used to describe a condition that matches the characteristics of a
pervasive developmental disorder (impaired social skills, impaired
language skills, and repetitive behaviors or interests), but does
not seem to match any of the other four pervasive developmental
disorders.
No single behavior can be used to identify an autism spectrum
disorder. Other conditions can have similar symptoms. Also the
impairments can range from mild to severe, so you cannot rule out
the condition simply because one impairment seems relatively mild.
Some of these behaviors occur in most children. However, the
frequency and duration of these behaviors are atypical for the
child's age group.