The Symptoms and Treatment of Atypical Autism

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The classifications of the autism spectrum describe varying conditions that differ in symptoms of social and behavioral impairment. These labels can cause confusion, especially among parents and educators. The most confusing label of all can be atypical autism, also known as Pervasive Development Disorder – Not Otherwise Specified (PDD-NOS). The five neurological disorders on the spectrum, autism or autistic disorder, Asperger’s syndrome, PDD-NOS, Rett syndrome, and Childhood Disintegrative Disorder, are in fact all considered pervasive development disorders. What makes PDD-NOS different, though, is a lack of lengthy criteria for the disorder.

A diagnosis of PDD-NOS is given when an individual has speech, communication, and/or social impairments, but does not meet the criteria for autism or another defined PDD. In other words, according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), an individual with PDD-NOS has mild symptoms of autism in most areas, or more severe symptoms in one area. As with other diagnoses on the autism spectrum, each case of atypical autism or PDD-NOS is unique. Each person will experience a different number of symptoms and different degrees of impairment.


A diagnosis of atypical autism, or PDD-NOS, is usually made before a child turns three. Some common symptoms include:

  • Limited speaking abilities and smaller vocabularies than individuals of the same age;
  • A tendency to isolate from others, showing no interest in interacting;
  • If social interaction is desired, having the inability to communicate effectively;
  • Difficulty developing relationships with family or friends;
  • Avoidance of physical contact with others, such as handshakes or hugs;
  • Inability to understand or respond to common gestures;
  • A need to maintain strict schedule and may display emotional outbursts if not followed;
  • Oversensitivity to stimuli, including lights, noises, tastes, and smells, and;
  • Strong preference for certain foods, and intolerant of tasting new foods.

Diagnosis and Treatment

Although any diagnosis of an autism spectrum disorder can devastate parents, the particular label of PDD-NOS can be especially frustrating. On one hand, some parents feel the diagnosis includes children who are on the spectrum, but do not quite fit under another category. Some also think that the diagnosis of PDD-NOS can be less stigmatizing than the diagnosis of autism. Some parents, however, feel the diagnosis is nonspecific, and that two clinicians evaluating the same child could likely offer two different diagnoses. The parents who feel that PDD-NOS is less stigmatizing admit that this diagnosis can make receiving services harder as well.

Still, the earlier a child is diagnosed with PDD-NOS, the sooner treatment can begin. Developmental pediatricians, pediatric psychiatrists, pediatric neurologists or pediatric psychologists are experts in diagnosing autism. These professionals can help parents figure out the best treatment plan, which aims to improve language, behavioral, and social skills. Treatment may include support and facilitation, Applied Behavior Analysis, educational services, and medication.


Boyse, K. (2008). Autism, autistic spectrum disorders (asd) and pervasive developmental disorders (pdd). University of Michigan Health System. Retrieved October 9, 2010, from

Interactive Autism Network. (2007). Pdd-nos. Retrieved October 9, 2010, from