Causes of Autism Spectrum Disorder

Possible causes of autism spectrum disorder, such as genetics and environmental influences, and what does not cause autism.

If you're wondering what causes autism spectrum disorder, the dissatisfying reality of it is that experts don't really know. Scientists believe it's due to a variety of things, including genetic and environmental factors. In the past 50 years, researchers have conducted numerous studies leading to various theories about autism spectrum disorder causes, but the scientific community has yet to identify specific and exact causes.

Insight into Possible Causes of Autism Spectrum Disorder

Advanced maternal age during pregnancy is thought to be one of the possible causes of autism spectrum disorder. Other things thought to possibly contribute to development of the disorder include:

  • use of medications during pregnancy
  • bleeding while pregnant
  • gestational diabetes
  • other complications of pregnancy

But none of these possible causes are proven. Much more research is needed to prove or disprove these maternal influences. (Get information on austism spectrum disorder symptoms and autism assessment)

Autism is a symptom of several known neurological disorders, supporting the theory that it is a biologically based disorder. These neurological disorders include:

  • Fragile X syndrome (an inherited disorder)
  • Tuberous sclerosis
  • Cerebral dysgenesis (abnormal brain development)
  • Rett syndrome (caused by a single gene mutation)
  • Metabolic or biochemical defects

Brain studies have shown that individuals with autism have brain structure abnormalities. We also know that if a close family member has autism, the risk of other family members having it is greater. Boys are four times more likely than girls to have autism. It's likely that autism develops due to genetic issues that result in neurological or biological differences in the brain.

What Does Not Cause Autism Spectrum Disorder

Definitive research has shown that bad parenting does not cause autism spectrum disorder; nor, do vaccines. Others have suggested that dietary sensitivity, heavy metal exposure, and exposure to other environmental pollutants could cause autism, but there is no reliable scientific data to support these as even possible causes. There are no known psychological factors that research shows cause autism.

article references

APA Reference
Gluck, S. (2022, January 10). Causes of Autism Spectrum Disorder, HealthyPlace. Retrieved on 2024, July 21 from

Last Updated: January 16, 2022

Medically reviewed by Harry Croft, MD

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