What Are the Causes of Autism?

Posted on 10-02-2021 by admin

What Are the Causes of Autism?

The prevalence of autism has risen steadily since researchers in the US began tracking it in 2000. Since then, a common question for most is what are the causes of autism?

What we know for sure is that scientists have yet to identify any confirmed cause of autism. However, research suggests that autism develops from a combination of genetic and nongenetic, as well as environmental influences that appear to increase the risk of a child developing autism.

Nonetheless, it is important to keep in mind that increased risk is not the same as cause. For example, some gene changes that are associated with autism can also be found in people who aren’t diagnosed with the disorder. Similarly, not everyone exposed to an environmental risk factor for autism will develop the disorder. As a matter of fact, most will not.

Genetic risk factors of autism

Research has discovered that autism tends to run in families. Changes in certain genes tend to increase the risk that a child will develop autism. If a parent carries one or more of these gene changes, they may get passed to a child (even if the parent does not have autism). Other times, these genetic changes arise spontaneously in an early embryo or the sperm and/or egg that combine to create the embryo. Once again, the majority of these gene changes do not cause autism by themselves — they simply increase risk for the disorder.

Environmental risk factors of autism

Research also shows that certain environmental influences may further increase – or reduce – autism risk in people who are genetically predisposed to the disorder. Importantly, the increase or decrease in risk appears to be small for any one of these risk factors:

Factors that increase the risk of autism

  • Advanced parent age (either parent)
  • Pregnancy and birth complications (e.g. extreme prematurity [before 26 weeks], low birth weight, multiple pregnancies [twin, triplet, etc.])
  • Pregnancies spaced less than one year apart
  • having an immediate family member with autism
  • genetic mutations
  • fragile X syndrome and other genetic disorders
  • metabolic imbalances
  • exposure to heavy metals and environmental toxins
  • a history of viral infections
  • fetal exposure to the medications valproic acid (Depakene) or thalidomide (Thalomid)

Factor that decreases the risk of autism

  • Prenatal vitamins containing folic acid, before and at conception and through pregnancy

Factors that have zero effect on the risk of autism

  • Prenatal vitamins containing folic acid, before and at conception and through pregnancy

Each family has a unique experience with an autism diagnosis and for some, it corresponds with the timing of their child’s vaccinations. With the sudden rise of the anti-vaccine movement, scientists have conducted extensive research over the last two decades to determine whether there is any link between childhood vaccinations and autism. The results of this research is clear: vaccinations do not cause autism. The American Academy of Pediatrics has compiled a comprehensive list of this research to support this finding.

  • Discrepancy in brain biology

How do genetic and non-genetic influences give rise to autism? Most appear to affect crucial aspects of early brain development. Some appear to affect how brain nerve cells, or neurons, communicate with each other. Others appear to affect how entire regions of the brain communicate with each other. Research continues to explore these differences with an eye to developing treatments and supports that can improve quality of life.


Autism is a lifelong disorder that, due to its causes not being known, are, therefore, not 100% preventable. There are also no cures for autism. The most effective treatments involve early and intensive behavioral interventions. The earlier a child is diagnosed and enrolled in a special behavioral therapy program, the better their outlook will be as an adult.Do you have a child with autism who requires behavioral therapy? Get in touch with us to know how Saint Clare can help you and your child improve your life for the better