WHAT CAUSES SPECIAL KIDS?
The cause of autism remains unknown. Scientists believe that autism herbs is a neurological disorder that affects the functioning of the brain. Brain scans of people with or without autism reveal differences in the structure and the shape of the brain.
Some people are also genetically more prone to autism. It is not uncommon to see more than one child with autism within one family. A number of children with autistic spectrum disorders or ASDs also have problems with their immune and biochemical systems. These special kids children react often quite badly or are intolerant to certain types of food, washing powders, etc.
Researchers are also of the opinion that there are other possible causes, which include heredity and genetics, but also a number of medical conditions (such as Fragile X syndrome) or the intake of harmful substances by the mother during pregnancy as well as other environmental factors. Over the past few years, the media have often reported fears on a possible link between childhood vaccination and autism. However, no conclusive evidence is available to substantiate this claim.
Theories on the cause of autism
Association with developmental brain abnormalities
Over the past two decades a number of studies of the brain - using imaging techniques and autopsies of individuals with autism - have revealed a variety of developmental brain abnormalities. However, none of the observed abnormalities seem to be consistent or specific for autism.
Evidence for a genetic cause
Before 1970, researchers were convinced that autism was the result of cold, unloving parenting (also known the "refrigerator mother theory"). However studies discredited these opinions as they demonstrated higher incidence rates of autism in identical twins and siblings and provided strong evidence of a genetic contribution to the cause of autism. However, despite extensive research the genetic cause for autism is not yet understood. Impact of environmental factors
Environmental risk factors are also believed to play a crucial role in autism. In the 1970s a relationship between congenital rubella and autism was observed. A link between prenatal thalidomide exposure and autism has also been established. Epidemiological studies of other medications used during pregnancy or chemical exposures in pregnancy found no conclusive evidence of a link with autism.
More recently the possible role of childhood vaccination in autism has been the subject of heated debate and many parents have refused to have their children vaccinated with the triple MMR (measles, mumps, rubella) vaccine.
This is especially the case in the United Kingdom. In 1998, a group of researchers at one of the major London hospitals published the results of a study documenting irritable bowel disease in a small number of children with autism. According to the study, most of the children's parents reported onset of autistic symptoms just after the triple MMR vaccination. The researchers claimed that the use of the MMR vaccine in special kids children was associated with an increased risk of autism. At that time, other researchers also pointed to the widespread use of the mercury-containing preservative in childhood vaccines as a contributory factor for autism.
The media also reported the incidence of development regression in children who had been given the vaccine. These children developed normally until between the age of 2 or 3 years old, when they suddenly started showing signs of regression such as: loosing their ability of language or speech, their ability to interact socially and respond to signs of affection and showing signs of unusual or - in severe cases - aggressive behaviours.
Although numerous parents are convinced that there is a link between autism and the MMR vaccine, no conclusive evidence of a relationship between the MMR vaccine and autism has been found. Between 2000 and 2001, three expert reviews unanimously concluded that the available data at the time of the claims did not support this association. A large-scale study in 2002 also reported no association. With regard to thimerosal exposure or the mercury-containing preservative used in childhood vaccines, expert review panels also reached similar conclusions, although fewer data are available.
Association with other medical conditions