The Different Types Of Autism

By Debra Kelly on Wednesday, February 17, 2016
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“The effort to cure autism, [autism rights advocates] say, is not like curing cancer, but like the efforts of a previous age to cure left-handedness.” —Amy Harmon

In A Nutshell

The term “autism” refers to a series of disorders that are largely characterized by the amount of difficulty the person has with social and communication skills. Those diagnosed with Asperger’s syndrome are on the high-functioning end of the spectrum, often possessing a high intelligence along with their social difficulties. Childhood disintegrative disorder is characterized by a regression into autistic symptoms where there were none before, PDD-NOS is diagnosed when a child doesn’t meet the full criteria for autism but displays some characteristics, and Rett syndrome is a physically debilitating version of the disorder that strikes mostly girls.

The Whole Bushel

Broadly speaking, autism and autism spectrum disorders encompass a group of disorders characterized by abnormal brain development that primarily impacts a person’s ability to interact with others in a social situation and to communicate effectively. Also common among the disorders is the presence of unusual or repetitive behaviors, non-traditional reactions to outside stimuli, and unusual ways of learning. These symptoms form the basis of what’s usually called classic autism.

Beneath the umbrella term of autism, there are five distinctly different subtypes: Asperger’s syndrome, autism (or classic autism), childhood disintegrative disorder, PDD-NOS, and Rett syndrome.

Those diagnosed with Asperger’s syndrome are on the high-functioning end of the autism spectrum, and symptoms of the disorder only involve the social side of diagnostic criteria. Many demonstrate repetitive speech patterns, difficulty interacting with people, difficulty interpreting nonverbal communications such as body language, difficulty relating to someone on an emotional basis, and difficulty reading social cues.

Asperger’s syndrome is set apart from other types of autism in that there are not usually learning difficulties associated with it. Many diagnosed with the condition demonstrate high academic achievement, especially within a very specific field of study.

Asperger’s syndrome is also unique in that some cases won’t be diagnosed until a person has reached adulthood. Other types of autism are often demonstrated and diagnosed in early childhood.

Comparatively, those diagnosed with classic autism will show all or many of the symptoms of social difficulties along with learning or academic difficulties. Other characteristics include the need for a regular routine, sensitivity to stimuli, and a deep fixation on particular hobbies or interests.

Childhood disintegrative disorder is a relatively rare form of autism in which children develop as typical until they are around three or four years old, then demonstrate a rapid regression and loss of social skills. Generally, the regression lasts for a few months until the child settles into a state that is basically classic autism.

PDD-NOS stands for “pervasive developmental disorder not otherwise specified.” The designation was developed in the 1980s to refer to those who demonstrated some of the characteristics of autism but not enough of the symptoms to justify a full diagnosis.

Those diagnosed with PDD-NOS can gradually be re-diagnosed as one of the different types of autism, or they can remain the same.

Rett syndrome is also a rare type of autism. While autism as a whole occurs in a higher percentage of boys than girls, those diagnosed with Rett syndrome are almost entirely female. Rett syndrome is also the most physically severe of the different types of autism, with sufferers often requiring specialized care around the clock.

Difficulties can include seizures and tremors, major digestive difficulties, an impaired heart and circulatory system, loss of motor control, difficulty breathing, fragile bones, and scoliosis. Occurrences of Rett syndrome have been linked to the specific gene MECP2, a gene defect that seems to occur randomly.

Show Me The Proof

Autism Speaks: What Is Asperger’s Syndrome?
Autism Science Foundation: What is Autism?
Rett Syndrome Research Trust
National Autistic Society: Autism; The use and misuse of diagnostic labels
Autism Program at Yale: Childhood Disintegrative Disorder