Types of autism

Autism presents in a wide degree, from thoseconception that autistic individuals with a high level
who are nearly dysfunctional and apparentlyof intellectual functioning in fact have Asperger's
mentally disabled to those whose symptoms aresyndrome, or that both types are merely 'geeks'
mild or remedied enough to appear unexceptionalwith a medical label. The popular depiction of
("normal") to others. Although not used orautism in the media has been of relatively severe
accepted by professionals or within the literature,cases (for example, as seen in the films Rain Man
autistic individuals are often divided into those withand Mercury Rising), and in turn many close
an IQ<80 referred to as having "low-functioning autism" (LFA), while those with IQ>80 are referred to as havingfriends and relatives of those who have been
"high-functioning autism" (HFA).[48] Low and highdiagnosed in the autistic spectrum choose to
functioning are more generally applied to how wellspeak of their loved ones as having Asperger's
an individual can accomplish activities of daily living,syndrome rather than autism.
rather than to IQ. The terms low and highThe extent to which someone with higher
functioning are controversial and not all autisticsfunctioning autism or Asperger's syndrome may
accept these labels. Additionally, a recent reviewexcel is theoretically quite high. For example,
questioned the validity of IQ testing of autisticHenry Cavendish, one of history's foremost
people.scientists, may have been autistic. George Wilson,
This discrepancy can lead to confusion amonga notable chemist and physician, wrote a book
service providers who equate IQ with functioningabout Cavendish entitled, "The Life of the
and may refuse to serve high-IQ autistic peopleHonourable Henry Cavendish", published in 1851.
who are severely compromised in their ability toFrom Wilson's detailed description it seems that
perform daily living tasks, or may fail to recognizewhile Cavendish may have exhibited many classic
the intellectual potential of many autistic peoplesigns of autism, he nevertheless had an
who are considered LFA. For example, someextraordinary mind.
professionals refuse to recognize autistics whoAutism as a spectrum disorder
can speak or write as being autistic at all, becauseAnother view of these disorders is that they are
they still think of autism as a communicationon a continuum known as autistic spectrum
disorder so severe that no speech or writing isdisorders. Autism spectrum disorder is an
possible.increasingly popular term that refers to a broad
As a consequence, many "high-functioning" autisticdefinition of autism including the classic form of
persons, and autistic people with a relatively highthe disorder as well as closely related conditions
IQ, are under diagnosed, thus making the claimsuch as PDD-NOS and Asperger's syndrome.
that "autism implies retardation" self-fulfilling. TheAlthough the classic form of autism can be easily
number of people diagnosed with LFA is not risingdistinguished from other forms of autism
quite as sharply as HFA, indicating that at leastspectrum disorder, the terms are often used
part of the explanation for the apparent rise isinterchangeably.
probably better diagnostics. Many also think thatA related continuum, Sensory Integration
ASD's are being over diagnosed: (1) because theDysfunction, involves how well humans integrate
growth in the number and complexity ofthe information they receive from their senses.
symptoms associated with autism has increasedAutism, Asperger's syndrome, and Sensory
the chances professionals will erroneously diagnoseIntegration Dysfunction are all closely related and
autism and (2) because the growth in servicesoverlap.
and therapies for autism has increased theSome people believe that there might be two
number who falsely qualify for those often freemanifestations of classical autism, regressive
services and therapies.autism and early infantile autism. Early infantile
Asperger's and Kanner's syndromesautism is present at birth while regressive autism
In the current Diagnostic and Statistical Manual ofbegins before the age of 3 and often around 18
Mental Disorders (DSM-IV-TR), the mostmonths. Although this causes some controversy
significant difference between Autistic Disorderover when the neurological differences involved in
(also known as Kanner's syndrome) andautism truly begin, some speculate that an
Asperger's syndrome is that a diagnosis of theenvironmental influence or toxin triggers the
former includes the observation of "delays ordisorder. This triggering could occur during
abnormal functioning in at least one of thegestation due to a toxin that enters the mother's
following areas, with onset prior to age 3 years:body and is transferred to the fetus. The
(1) social interaction, (2) language as used in socialtriggering could also occur after birth during the
communication, or (3) symbolic or imaginativecrucial early nervous system development of the
play", while a diagnosis of Asperger's syndromechild.
observes "no clinically significant delay" in the latterA paper published in 2006 concerning the
two of these areas.behavioral, cognitive, and genetic bases of autism
While the DSM-IV does not include level ofargues that autism should perhaps not be seen as
intellectual functioning in the diagnosis, the facta single disorder, but rather as a set of distinct
that those with Asperger's syndrome tend tosymptoms (social difficulties, communicative
perform better than those with Kanner's autismdifficulties and repetitive behaviors) that have their
has produced a popular conception thatown distinct causes. An implication of this would
Asperger's syndrome is synonymous withbe that a search for a "cure" for autism is unlikely
"higher-functioning autism", or that it is a lesserto succeed if it is not examined as separate, albeit
disorder than autism. Similarly, there is a popularoverlapping and commonly co-occurring, disorders.