Pervasive Developmental Disorder - The Autism You Don't Know About

To understand what Pervasive Developmental Disorder (Not Otherwise Specified) is, why it is misunderstood, and why it is often misdiagnosed is to understand the condition as a whole. We must understand how it is diagnosed, the symptoms and/or behaviors doctors, psychologist and parents look for to make a diagnosis, how PDD (NOS) can be treated, the differences among other disorders that follow along with PDD (NOS), and how this disorder affects the person who has it and those that are in direct contact with them. PDD (NOS) is also referred to as atypical autism. "It is a 'sub threshold' condition in which some - but not all - features of autism or another explicitly identified Pervasive Developmental Disorder are identified." (Autism Society of America Oakland Chapter)

There is no direct cause of PDD (NOS) to this date. Although there have been several theories written on what causes this disorder. Because PDD (NOS) has the characteristics of autism these theories have been based on those particular characteristics. These characteristics include: "repetitive movements and behaviors, deficits in nonverbal communication, deficits in social behavior, difficulty with changes in environment, and uncommon responses to tastes, sight, sound, smell and touch"(Center for Autism and Related Disabilities). As with regular autism, the problems with taste, sight, sound, smell and touch are classified as a Sensory Deficiency. It is common to have at least one of these deficiencies if diagnosed with a type of autism.

It is known now that autism is derived somewhere from abnormal brain development, however, there are several different opinions about where exactly in the brain the abnormalities have taken place. Two psychological theories that give their hypothesis as to the cause and where in the brain abnormal development comes from are, the theory of mind (TOM) deficit hypothesis and the socio-emotional deficit hypothesis.