A GUIDE TO CLASSIFICATION
& DIAGNOSIS
The classification and diagnosis
of autism, Aspergers
syndrome and other related disorders is constantly changing,
and is increasingly the subject of much discussion and dispute.
The manifestations of these disorders cover a
wide spectrum, ranging from individuals with severe impairments—who
may be silent, mentally disabled, and locked into hand flapping
and rocking—to less impaired individuals who may have active but
distinctly odd social approaches, narrowly focused interests, and
verbose, pedantic communication.
Although there are various diagnostic frameworks
available, the most common to date is the Diagnostic and Statistical
Manual of Mental Disorders (DSM-IV). Part of the confusion around
classifying these disorders is that the characteristics vary so
widely from child to child. There has been an trend to refer to
children and adults being on the 'autism spectrum', a term coming into wider international usage. The
fact sheets on this site will use this term frequently.
Pervasive Developmental Disorders (PDD)
The term Pervasive Developmental Disorders, or
PDD, has been in use for many years and has been the traditionally
accepted way to group disorders such as autism and Asperger's syndrome.
This came about because the most common tool used for diagnosis,
the Diagnostic and Statistical Manual of Mental Disorders, uses
this framework. The DSM-IV has evolved over time and the fourth
issue includes autism and Asperger's syndrome in a group of five
disorders called Pervasive Developmental Disorders:
Of the other four PDD forms, Asperger syndrome
is closest to autism in signs and likely causes; Rett
Syndrome and
childhood disintegrative disorder share several signs with autism,
but may have unrelated causes; PDD not otherwise specified (PDD-NOS)
is diagnosed when the criteria are not met for a more specific disorder.
Unlike autism, Asperger's has no substantial delay in language development.
Autism Spectrum Disorders (ASD)
There has been much discussion on this system
of classification and there has been an increasing move to see some
of these disorders as being placed on a spectrum. Autism is typically
called Autistic Disorder under this classification, although this
website still uses the term "autism" as it is the most
common terminology in use. Autism is grouped with Asperger's syndrome
and two other disorders as the Autism Spectrum Disorders. or Autism Spectrum Disorders:
While the DSM-IV does not portray this classification,
it may incorporated into a future edition. The term 'Autism Spectrum Disorder' or ASD, is being adopted widely, along with referring
to a child or adult as being 'on the autism spectrum'. For those
who follow this system, there is some debate over whether high-functioning
autism is simply Aspergers syndrome. This website is simply
intended to provide practical information and tips for parents,
friends, teachers, employers and the wider community, so these debates
will not feature strongly on this site.
The terminology of autism can be bewildering,
with autism, Asperger's and PDD-NOS often called the Autism Spectrum Disorders (ASD) or sometimes the autistic disorders, whereas autism
itself is often called autistic disorder, childhood autism, or infantile
autism. Sometimes people use the term 'autism' to refer to autistic
disorders or to Autism Spectrum Disorders, or equate Autism Spectrum Disorder with PDD. Autism Spectrum Disorder, in turn, is a
subset of the broader autism phenotype (BAP), which describes individuals
who may not have Autism Spectrum Disorder but do have autistic-like traits, such as avoiding
eye contact.
Differences between aspergers syndrome & high-functioning
autism
Although individuals with Asperger's syndrome
tend to perform better cognitively than those with autism, the extent
of the overlap between Aspergers
syndrome and high-functioning
autism is unclear.
A neuropsychological profile has been proposed
for Aspergers syndrome; if verified, it could differentiate between
Aspergers syndrome and high-functioning autism and aid in differential
diagnosis. Relative to high-functioning autism, people with Aspergers
syndrome have deficits in nonverbal skills such as visual-spatial
problem solving and visual-motor coordination, along with stronger
verbal abilities. Several studies have found Aspergers syndrome
with a neuropsychologic profile of assets and deficits consistent
with a nonverbal learning disability, but several other studies
have failed to replicate this. The literature review did not reveal
consistent findings of "nonverbal weaknesses or increased spatial
or motor problems relative to individuals with high-functioning
autism", leading some researchers to argue that increased cognitive
ability is evidenced in Aspergers syndrome relative to high-functioning
autism regardless of differences in verbal and nonverbal ability.
Aspergers syndrome may also be called Asperger
syndrome, Asperger's syndrome or simply Asperger's. It is hoped
we are moving to an internationally recognized system that will
provide consistency for everyone. For parents though, the key will
be practical strategies that help to minimize their child's developmental
delays and provide a better future - these strategies still apply
despite where researchers set the fence posts for classifying your
child's position on the autism spectrum.
This website focuses on Asperger's syndrome and
autism (or Autistic Disorder). To suit an international audience,
these fact sheets will refer to both Autism Spectrum Disorders
and Pervasive Developmental Disorders and use various terms more
or less interchangeably.
Click here for the full
range of Asperger's and autism fact sheets at www.autism-help.org
This autism fact sheet is licensed under the GNU
Free Documentation. It is derivative of an autism and Asperger's
syndrome-related articles at http://en.wikipedia.org |
