The various types of Autism are considered a “spectrum disorder” – an umbrella, with a range of autistic syndromes at varying degree of severities. It can also be depicted, and this is my preferred version while educating parents, as a rainbow where the colors blend and overlap. Each of the distinct color represents a particular category of autism. Yet, the transition from one color to the next on a rainbow is similar to the transition from mild to severe autism.

Autism Spectrum - The Rainbow Effect

Fig 1: Autism Spectrum – The Rainbow Effect

Each of these categories demonstrate varying degrees of  difficulties a person faces with social, verbal, communicative and repetitive behaviors. Just as a shade in a rainbow overlaps and blends with the next color, so does autism making it harder to determine where one level or type of autism starts and where it terminates.

Key Types of Autism

The Journey from Classical Autism to Autism Spectrum Disorder

Till about the 1970s, the classical autism studies included all shades of ASD bundled under a generic term ‘Autism’.
Today however, physicians, therapists and researchers consider each of these five categories while referring to specific autism symptoms:
Each type of Autism demonstrates a degree of  difficulty that a patient faces with verbal, social and communicative interactions. Just as a shade in a rainbow overlaps and blends to the next one, so does the autism spectrum; thus turning it into a challenging exercise for physicians to determine where one range in the spectrum starts and where it ends.
Mary Alexa, Autism Therapy Specialist

Autism Severities per Types

Asperger’s 35
Pervasive Developmental Disorder (PDD NOS) 55
Childhood Disintegrative Disorder 70
Classical Autism 85
Rett’s Syndrome 97


Support Classification of different Autism Types

Each of the above types of Autism mentioned earlier fall into one of the following categories, based on the level of support they require. For more details on the Autism Levels, please check out our page on Autism Spectrum Disorder DSM 5

Autism Forms Support Level Classical Autism Asperger’s PDD-NOS Rett’s Syndrome CDD
Mild Autism Level 1
Moderate Autism Level 2
Severe Autism Level 3

Table 1: A How the different types of autism align to the 3 major categories of severity


An Insight into the Various Types of Autism

Let us now get a deeper insight into each of the following forms of Autism.

Overlap between Asperger's and PPD NOS - key types of autism

Fig 3: Overlap between Asperger’s and PPD NOS

As mentioned at the beginning of this article, the various types of autism spectrum disorders present a significant overlap with one another. The following 3 characteristics are carefully evaluated to arrive at the right conclusion:

For example, it is extremely hard to discriminate between mild PDD and moderate Aspergers symptoms as a patient may demonstrate both characteristics in the autism spectrum quotient.

To conclude, even though these are the five main types of Autism, the actual list is far more extensive. It is highly likely that any particular individual can exhibit autistic trends from one or more forms of Autism and therefore may require a varying level of support from medical professionals, therapists and (above all) their families.

I am Ashish, the admin for this website. Having grown up with an Autistic brother, I understand the hurdles families face dealing with Autism. I have also realized that lots could be achieved by harnessing the strengths of Autistic children to integrate them into the society. Here, we share the objective to make that information freely available! Read more