What is Autism Spectrum Disorder

Updated: Oct 19, 2018


What is Autism Spectrum Disorder?


originally written for and published on Harkla.co

Autism is a developmental disorder that is marked by social communication deficits and restrictive or repetitive behaviors. That seemingly simple definition is deceiving, however, because the wide range of autism spectrum disorders affects each person with autism differently.

The Prevalence of Autism

In 2014, the U.S. Centers for Disease Control reported that 1 in 68 school-aged children were diagnosed with Autism Spectrum Disorder. A more recent parent survey conducted by the National Center for Health Statistics puts that number much higher, reporting 1 in 45 children aged 3 and older have autism. An autism diagnosis occurs across racial, socioeconomic, and ethnic groups. The latest research puts the incidence of autism as being 4.5 times more likely among boys than girls. With autism being an increasingly common diagnosis, it’s likely that someone you know or have interacted with recently has been affected by autism - in their families, communities, or schools.

Perhaps you’re reading this article to gain understanding as a supportive friend, curious neighbor, or concerned grandparent.


Perhaps you’re a parent reading this article in hopes of gaining some insight into your child’s development, and concerned about your child possibly having autism.

Whatever your reason for wanting to inform yourself on autism, hopefully this will provide you with the information you need to seek additional resources and be a more conscious citizen in your interactions with people on the autism spectrum.

What Causes Autism?

In 2013, an estimated $305.6 million went towards autism research (disability scoop). These funds paid for research on causes of autism, treatments, diagnoses, and services, among other issues. After an autism diagnosis, it is a common question for parents to ask: What caused my child’s autism? The current answer is: There is no simple response.

Research points to a combination of potential causes of autism that may or may not play a role in the diagnosis. Autism Speaks outlines three categories of risk factors that contribute to autism: genetic, environmental, differences in brain biology. Research supports that a combination of these risk factors results in autism but, just as every child with autism is different, potential “causes” or “combinations” of risk factors manifest differently for every child.


Here are some of the risk factors that research has supported:

  • Family history of autism (sibling has autism)

  • Advanced parent age

  • Genetic mutation

  • Sex of baby - boys are 4 times more likely than girls to have autism\

  • Extremely pre-term birth (prior to 26 weeks gestation)

  • Comorbid diagnosis such as Fragile X or Tuberous Sclerosis

Researchers are also investigating the potential risks associated with air pollution, and drug/toxic/heavy metal exposure prenatally, and reproductive assistance (IVF) for multiple births.

The Centers for Disease Control and Prevention is currently conducting a Study to Explore Early Development (SEED) across communities nationwide, to better understand potential risk factors for autism.

Hopefully, as additional research is funded and we learn more about the potential causes or risk factors associated with autism, a parent’s question can be answered with more clarity. Until then, there is no 100% answer which also means that autism is not a preventable diagnosis.

Early Signs of Autism

Your child’s pediatrician will screen your child for autism at well-check visits at 18-months and 24-months, however parents should always communicate concerns about your child’s development whenever you have them! This American Academy of Pediatrics article outlines what a well-check screening for autism could look like.


CDC.gov autism screening flow chart

image courtesy of CDC.gov

Signs of autism are categorized into social differences, communication differences, and behavioral differences (repetitive and obsessive behaviors). A skilled clinician who is trained in screening for autism will be able to explain how these differences go beyond some other “developmental delays.”

Here are some resources on the early signs and symptoms associated with autism.