Thus far, medical researchers have not been able to find the actual cause of autism. It is believed that the disorder is caused by abnormalities in the brain structure that results in a disorder in the mental development. The reason for this has never been pinpointed. Findings have only shown that patients with autism have abnormalities in several areas of the brain.

Speculations point to several causes of autism. These include genetics, environmental factors, metabolic disorders, viral infections or complications during pregnancy and delivery.

Genetically speaking, doctors are not able to narrow down the cause of autism to a single gene. The disorder is a result of several unstable genes, but they are all unpredictable. As a result, isolating which gene may turn "bad ? and cause autism is impossible. It is suspected that the combinations of different unstable genes increases the risk of autism in a patient.

Risk Factors

If someone in the family has already been diagnosed with autism, there is a higher risk that another child may be diagnosed with the same condition, especially if he is a first-degree relative.

Medical conditions like metabolic disorders, genetic disorders, developmental brain abnormalities and neurological disorders acquired after birth are risk factors that may lead to autism.

Environmental conditions that may aggravate genetic risks increase the incidence of autism in the family.

Rejected Speculations

There were several causes that were attributed to autism, but these were eventually dismissed. Among them were emotional trauma and vaccines.

It was believed that a child experiencing severe emotional trauma could acquire autism. But this state is a sign of anxiety disorder rather than autism.

Mercury found in early vaccines contained neurotoxins, and were blamed for autism. However, researches have concluded that the amount of mercury in a vaccine is not enough to cause such a disorder. There is no actual link between vaccines and autism, so this theory was proven wrong.