What is the Autism Spectrum and How Does It Affect a Person?

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Defining the Autism Spectrum

After a diagnosis of autism is presented, family and friends of the affected person often ask what is the autism spectrum.

The autism spectrum encompasses a number of conditions that range from severe cases of autistic disorder to milder cases of high-functioning Asperger’s Syndrome. Other conditions on the spectrum include the relatively rare Rett syndrome and childhood disintegrative disorder. If a person shows symptoms of autism but does not meet the specific criteria for any of the above conditions, they may be diagnosed with pervasive developmental disorder - not otherwise specified. (PDD-NOS) These five disorders make up the autism spectrum.

What Characterizes the Autism Spectrum

The autism spectrum is characterized by a cluster of symptoms that are common to all five conditions. These vary in intensity but will generally be apparent to one degree or another. They can be grouped in the following manner:

  • Social problems become apparent from an early age. Infants and children on the autism spectrum may have problems interacting with parents and other people. Eye contact is poor and social cues and body language are not understood.
  • Communication difficulties become apparent when children on the autism spectrum reach the age where speech should be developing. Some will remain non-verbal for life while others may have delayed speech. Problems with sentence construction, pedantic speech, and strange styles of speaking are also signs of autism. When speech fails, people on the autism spectrum may become frustrated and scream or simply grab what they want.
  • Repetitive behaviors are part of the autism spectrum disorders. These can take several forms including hand flapping, walking on the toes, and lining up toys in rows or certain formations. If a parent touches the toys, the child may have an emotional meltdown. People with autism need routine to function well, and repetitive behaviors are thought to be a part of this need for familiarity.

Problems That Are Part of the Autism Spectrum

When asking what is the autism spectrum, it is important to look at other signs and symptoms that may accompany the condition. These commonly include the following:

  • Sensory problems with sounds, tastes, textures, and smells. Responses to pain may be muted but a loud sound or scratchy labels in clothing can cause immense distress.
  • Seizures affect approximately 25% percent of children with autism spectrum disorder.
  • Mental retardation is often present to varying degrees. The person may have normal scores in some areas but score low in others.

Understanding the Autism Spectrum

The autism spectrum comprises five separate conditions that share common signs and symptoms. No two people will present with the same degree of impairment and the same problems, but similarities will be apparent. Understanding the spectrum and possible implications can make it easier for family and friends to adapt to the diagnosis. It is important to remember that the use of the word “spectrum” implies that a whole range of signs and symptoms may be present in varying degrees.


Children with Autism - A Parents' Guide, Michael D powers, Woodbine House, 2000

The Complete Guide to Asperger’s Syndrome, Tony Attwood, Jessica Kingsley Publishers, 2007

National Institute of Mental Health. Autism Spectrum Disorders. Retrieved at https://www.nimh.nih.gov/health/publications/autism/complete-index.shtml