ASD Etiology
ASD Etiology
ASD Etiology
Historical Perspective
In1943, Dr. Leo Kanner wrote a journal article
which described the behaviors of 11 children
with autism. Kanner called the disorder early
infantile autism. This term was later replaced
by the more modern, autistic disorder in the
1980s.
Kanner found, that the children in his study all
exhibited what he called extreme autistic
aloneness, the tendency to ignore, shut out,
or fail to respond to input coming from the
surrounding social environment.
Historical Etiology
During the 1940s, 50s, and 60s,
autism was thought to be a childhood
form of schizophrenia due to the
similar predisposition of persons with
both conditions to become absorbed
in an inner-world.
Refrigerator Mothers
Bruno Bettelheim believed the connection
between autism and schizophrenia was related
to parenting practices, a common theory during
this time. Bettelheim wrote:
Infants, if totally deserted by humans before
they have developed enough to shift for
themselves, will die. And if their physical
care is enough for survival but they are
deserted emotionally, or are pushed beyond
their capacity to cope, they will become
autistic.
Modern Theories
Many theories exist as to the causes
of autism and common behaviors of
those with ASDs.
These include: teratogen exposure
during pregnancy, genetic factors,
and environmental influences.
While research has proven this to be
untrue, many still believe that
childhood vaccines cause autism.
Faulty Theory
Vaccines have been a frequent
target of blame by parents looking
to explain their childs diagnosis.
The fact that childrens ASD
symptoms tend to become more
obvious around the age that the
MMR vaccine is administered has
perpetuated this myth. Thimerasol
in vaccines is NOT linked to autism
and this theory has been disproved
many times over.
Genetics
Family and twin studies have shown that
there is a recurrence risk of 2-8% for
subsequent children in a family which
already has 1 child with ASD.
In twin studies, the concordance of ASD
among identical twins is 77% and among
fraternal twins is 31%.
Both of these facts demonstrate a genetic
link to ASD, although no one gene has
been linked to autism.
Environmental Influences
While refrigerator mothers are not to blame for
ASD, prenatal exposures may be:
Maternal influenza and rubella infections during
pregnancy have been linked to higher incidents of
ASDs.
Exposure to medications such as thalidomide and
valporic acid have been linked to autism
Exposure to alcohol in utero is also linked to
higher incidence of ASDs.
Premature birth is linked to a higher risk of ASD
in young children.
After birth, heavy metal toxicity and pesticide
exposure can cause symptoms similar to those of
ASD.
Brain Differences
fMRI studies have shown that
children with ASDs view human
faces in the part of the brain that
typically developing children use for
viewing objects. This demonstrates
abnormal neural networks in
individuals with ASD.
Mirror Neurons
Batshaw et al. (2013), wrote there is evidence
that mirror neurons in the brain, which permit
imitation of what an individual sees, may be
functionally atypical (p. 348). This may be
tied to the deficits in gestures and facial
expressions seen in children with autism.
Because children learn most social conventions
through imitating their parents or other adults
in their lives, these dysfunctional mirror
neurons in persons with autism may be related
to many of their social skill deficits.
DIR/Floortime
Developmental, Individual-Difference, Relationship-Based
(DIR)/Floortime is an evidence-based practice used to help
children with ASD develop to their full potential. The method
was developed by Dr. Stanley Greenspan.
The Floortime model has parents attempt to engage with
children while they are engaging in activities they enjoy to help
open circles of communication. Floortime consists of the adult
following the childs lead, rather than expecting the child to
enter into adult-led play.
DIR/Floortime aims to help children reach 6
developmental milestones:
Self-regulation and interest in the world
Intimacy, or engagement in human relations
Two-way communication
Complex communication
Emotional ideas
Emotional thinking
Floortime, cont.
Because DIR/Floortime focuses on helping children develop social
relationships and communication skills, it seems ideally suited to help
overcome the social and communicative delays related to ASD.
In Conclusion
Many theories exist to explain the causes
and symptoms of autism spectrum
disorders.
Researchers have devoted years of their
lives and millions of dollars to further
understand this topic, to speculate on the
causes of autism as a casual observer is
unnecessary, but a combination of causes
seems likely.
There are many approaches to intervention
for children with ASDs, Floortime is just one
example that seems promising.