What Causes Autism?

You’ll hear a number of theories, some with some very vocal adherents, but the short answer is that we don’t really know. Scientists strongly suspect a genetic cause, or perhaps a genetic predisposition triggered by something that happens later in development or after birth in terms of environmental factors. This lack of clarity about the cause contributes to a considerable speculation among parents and scientists and conflicting theories about the cause or causes of autism.

Although autism was first identified in 1943, its cause remains unknown. The prevailing theory is that autism is a neurological disorder that affects the functioning of the brain. Brain scans of people with and without autism reveal differences in the structure and shape of their brains. Though much about autism remains a mystery, here are some observations made by researchers:

  • Some people are genetically more susceptible to autism
  • Individuals with autism seem to have abnormalities in the number of brain cells (neurons)
  • Serotonin levels are abnormal in some people with autism

The effort to find the cause of autism continues with investigations into a number of theories including:

  • Genetic
  • Immune system
  • Environmental factors


Autism and Vaccines

Although some parents of children with autism suggest that there is a link between then MMR vaccine (injection of a mixture of three live attenuated viruses for immunization against measles, mumps, and rubella), to date, there is no scientific proof that any vaccine causes autism. The age for autism diagnosis is normally between years one and three, while children are vaccinated around the age of two. This can often lead parents to link the development of autism symptoms to the injection of the MMR vaccine. There is ongoing research that aims to discover a possible link between vaccines and autism; however, there is currently no definite proof for this link and it is important to note that vaccines help protect and strengthen the body's immune system.