Autism is a condition that has been with humanity since the start of the species, but unlike some other illnesses, such as tuberculosis, or pneumonia, it was not easily recognized. For centuries, autism wasn’t even regarded as a distinct condition but was often misdiagnosed as other forms of illness. It wasn’t unheard of, for example, for certain types of autism to be diagnosed as schizophrenia, and for patients with such a diagnosis to be treated with antipsychotic medication because some of their symptoms would respond to that treatment.
Today, however, it is a very different situation. Medical science has grown both more advanced and more nuanced, and autism, or Autism Spectrum Disorder (ASD) as it is currently known, is better understood, and given its own distinct medical category. That doesn’t mean that ASD is completely understood, or that there is a cure for it, but the more focused awareness of the condition and its related symptoms means that better research and treatment is now being done.
One of the unique things about ASD is how varied its symptoms are. It’s because of this that when ASD was first given its own category in medical texts, it was initially broken up into four categories. Today, this is no longer the case, but because the change in medical interpretation was recent, having only taken place in 2013, many people are still more familiar with the “classic” categories. There are the autism types people used to be classified under.
The Changing DSM
The classification and diagnosis of ASD are, at least in American medicine, largely defined by on important medical publication, and that is the Diagnostic & Statistical Manual of Mental Disorders, more commonly known as “DSM,” published by the American Psychiatric Association. The DSM was first published in 1952 and is now known as DSM-I. Every time there is a major revision, a new version of the DSM appears.
It was in DSM-II, in 1974, that ASD was first given an entry in the manual, although it was a very different interpretation of the disorder at the time, defined as a psychiatric condition arising from being raised by a cold or distant mother. In DSM-III in the 1980s, ASD was finally recognized as a neurological/developmental condition, and the four classic categories were established.
Considered the “high functioning” version of the disorder, people with Asperger’s experienced the “mildest” symptoms, to the point where some weren’t even diagnosed and were merely considered “eccentric” or “quirky” people. Those with Asperger’s were generally considered able to cope with daily life requirements, though there might be some difficulty in socializing.
Pervasive Developmental Disorder, Not Otherwise Specified
Usually referred to as PDD-NOS, this was a miscellaneous category for people with more severe ASD symptoms. Here the socialization issues are more pronounced, and there may also be additional behavioral symptoms that interfere with other aspects of life, such as work. PDD-NOS was a problematic category because so many people fell into this classification.
This is the “classic” form of ASD, made most famous by the movie Rain Man. Symptoms are much more intense, often leading to an inability to live a normal life. This requires more extensive attention and treatment, and has more visible symptoms such as strongly repetitive motions, very specific means of communication, inability to maintain eye contact, aversion to touching and others.
Childhood Disintegration Disorder
CDD, as it is called, was often considered the most severe form, not only because of how intense the symptoms were but because of the regressive nature of the disorder. Unlike the others, that may have shown evidence early people with CDD may appear to develop normally for a few years, and then display regression, losing language skills, socialization etiquette and even reflexes.
In 2013, with DSM-V, the decades of research finally concluded that four categories of high and low functioning ASD were too simple to convey the condition of ASD accurately. So the four categories were done away with, replaced instead with Autism Spectrum Disorder, with the emphasis being on individual symptoms diagnosed individually, on a spectrum.
This does away with the big problem the previous classification system had, where so many people fell under “miscellaneous” that PDD-NOS diagnoses were out of proportion with other classes, since many people with ASD did not fit “neatly” into the other three categories, thus calling the accuracy and effectiveness of those categories into question.
There is still some lingering stigma from the previous categories, with some biases towards “high functioning” and “low functioning” ASD as a simple way to distinguish a mild case from a severe one. However, the more accurate diagnoses look at what each person’s symptoms are, and how severe or not those individual characteristics are, to come up with an individual approach for the treatment and symptom management, rather than trying to apply only one of four possible treatment possibilities based on categorization.