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What Exactly is PDD NOS?


Many children are diagnosed with pervasive development disorder- not otherwise specified, a subthreshold under the overall umbrella of autism the isn't quite fully part of the disorder. PDD-NOS does, however place children somewhere on the spectrum, just as Asperger's Syndrome and Rhett's Disorder. With last year's DSM-V absorbing many of the disorder characteristics into itself, however, where does PDD-NOS fall now?

Autism is an interesting disorder. There is major debate at the moment about whether or not it is genetic or induced through vaccination, a disagreement between two parties that I rarely get involved in. The fact of the matter is that scientists use twin studies to figure out the extent to which a disorder is indeed genetic, on which has found extremely high rates (up to 95%) among identical twins and quite high rates (up to 31%) among fraternal twins, pointing heavily towards genetics being the main cause.

Autism may not seem like it has a specific look but one particular study mapping 17 different points on the faces of young white (caucasian) boys has found that the features are shared and make a child all that more beautiful. As such, it points towards certain chromosomal changes or genetic mutations which place children on the rainbow, colours which are used to represent how similar yet different every autistic child is. After all, there are so many subcategories that the children could be diagnosed under.

What is PDD-NOS?

The term Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS), also referred to as an atypical personality development or "atypical autism" because it has some of the PDD characteristics, was included in the DSM-IV to encompass cases where there is marked impairment of social interaction, communication, and/or stereotyped behavior patterns or interest. PDD alone marks a child as autistic and is not a diagnosis on its own, whereas the addition of -NOS makes it so. The diagnosis of PDD-NOS is based on behavioral observations and clinical experience. The label itself is quite new, only dating back 15 years, meaning that sufficient research does not yet exist to clearly define its boundaries.

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In the case of PDD-NOS, there are no specific criteria under which children are diagnosed, merely that there are particular differences separating it from ASD as a whole:

  • Fewer intellectual deficits
  • Some noted deficits in peer relations
  • Unusual sensitivities
  • social skills are less impaired than in classical autism

Note: Because a child has been diagnosed with PDD-NOS or autism does not mean that they necessarily have an intellectual impairment. On the contrary, many high-functioning autistics have intellects superior to that of their peers.

A study looking into the autism prevalence among today's children in 2011 found that of the 132 infants who screened positive (103 boys and 29 girls), 40.9% had autistic disorder and 59.1% had a pervasive developmental disorder not otherwise specified (PDD-NOS). The latter diagnosis was used to describe individuals who did not fully meet the criteria for ASD or Asperger's.

Personally, I find the strengths listed on the Emory Autism Center page to be quite inspiring. An autism or PDD-NOS diagnosis does not mean your child is any less than others, merely different in the way he/she interacts. Furthermore, he/she might just be the smartest kid in class, no matter the age!


  • Good memory, especially for visually presented information
  • Enjoys completing tasks with a set end point
  • May have precocious interest in letters and numbers
  • Cuddly and affectionate with parents, usually on own terms
  • Mechanical aptitude (can program the VCR at age 2)
  • Higher skills/talents in art, music, math, balance
  • Enjoy vestibular stimulation (tosses, being turned upside down, etc)
  • Stamina
  • Good non-verbal problem solving abilities (can get what they want)

Other References:
Yale University
Center for Disease Control and Prevention