C
CAUSES OF AUTISM:
Autism has no single cause. It is what is called a phenotype in that it most likely has multiple causes.
Genetic:
Siblings of persons with autism are 5% more likely to have autism which is a risk of 1 in 20 which is greater than general population.
In Identical twins if one has autism the other is more likely to have autism also than for just one of them to have it.
Higher incidences in Parents and sibling of people with autism to have milder but similar language, social and learning differences.
At this time no single gene has been found to be responsible for autism and it is more likely different genes from different families.
It is also likely that it is a gene that requires a trigger factor.
Environmental Factors
Environmental factors such as viruses, allergens and chemicals.
Immune factors are sometimes suspected and I put it under environmental because there is less research that immune deficiencies are causal but may be secondary to anti-biotic use, vaccines, and chronic conditions such as allergies.
BRAIN ABNORMALITIES
Studies on people with autism have found abnormalities in several regions of the brain, including the cerebellum, amygdala, hippocampus, septum, and mamilary bodies.
Nerve fibers appear smaller than normal and have stunted nerve fiber.
(Courchesne .... Bauman and Kemper)
These studies suggest that autism results from disruption of normal brain development possibly early in fetal development.
The functional deficits are likely to be a result of the way the structures of the brain develop and process information as an integrated whole.
Neurotransmitters
Other studies suggest that people with autism have abnormalities of serotonin and other signaling molecules.
We may not understand Autism fully but several older theories about the cause of autism have been now proven false.
Autism is not a mental illness.
Autism is not caused by bad parenting.
No known psychological factors in the development of the child have been shown to cause autism.
T
oday, autism is a national crisis affecting over 400,000 families and costing the nation over 13 billion dollars a year.
Estimates have increased from 5 in 10,000 ti as much as 11 to 21 per 10,000 (Gillber, 1990; Wing and Gould 1979) and ccording to recent studies, as many as 2 in every 1000 children born today will be on the autistic spectrum.
Occurrence in males 4x's greater than in females
Found in people of all races and social background
Autism is the 3rd most common childhood disorder more common than Down syndrome, multiple sclerosis or cystic fibrosis and yet,
autism research still receives less than 5% of the funding of these other diseases.
Some sources indicate that Autism/PDD is the fastest growing childhood illness and practioners across the country are claiming to see increasing numbers of these children.
Occupational therapists are being increasingly asked to address the needs of these children in both public and private settings.