The Clinical Definitions of Autism, Asperger’s, and PDD-NOS

by Tim on February 19, 2009

As a preamble to the upcoming sequel to “What’s Your Autistic Toddler Like?” (coming very soon!), I thought we should first go straight to the source in which the diagnoses are defined – the Diagnostic and Statistical Manual of Mental Disorders – Fourth Edition or DSM-IV. (Technically, it’s DSM-IV-TR, where TR stands for ‘text revision’, but whatever.) The people who evaluate your child don’t sit there with just this list and check off boxes, though. The diagnostic tests they do are far more nuanced, but they are in their own ways based on these criteria.

This is one place where those five-digit codes – known as ICD-9 codes – you might see on medical forms and reports (e.g., 123.45) come from. For the record, ‘Autistic Disorder’ is 299.00 and Asperger’s is 299.80, in case you were wondering.

[Standard Disclaimer – This is not some diagnose-it-yourself kit for you to use on your child. A formal diagnosis must be made by a qualified, experienced professional. This is just to give you some idea of what you are looking for. If you suspect your child may have autism, read our “Five Things You Can Do If You Think Your Child Has Autism” post, and especially note the M-CHAT questionnaire. Don’t just say, “My kid only gets 5 out of 6 so there’s nothing to be concerned about.” It’s important that you go over any questions and concerns with qualified people; don’t just go ‘by the book’.]

This is what that text says (below, or “Click to Continue” if you’re reading this as an excerpt). I will say one thing before plowing ahead – our children and their challenges are far more complex than what can be covered in a diagnostic manual. Think of this like a starting place where the road that follows is full of difficulties, surprises, challenges, unknowns, adventures, and joys.

Source: The Centers for Disease Control and Prevention.

Diagnostic Criteria for 299.00 Autistic Disorder

[Note from Tim: Items A, B, and C all have to be true.]

A. A total of six (or more) items from (1), (2), and (3), with at least two from (1), and one each from (2) and (3):

[Another note from Tim: For the visual learners among you, you need six total from the following three lists – with at least two greens, one purple, and one orange. That’s assuming you or your browser isn’t color blind.]

(1) qualitative impairment in social interaction, as manifested by at least two of the following:

a. marked impairment in the use of multiple nonverbal behaviors such as eye-to-eye gaze, facial expression, body postures, and gestures to regulate social interaction

b.failure to develop peer relationships appropriate to developmental level

c. a lack of spontaneous seeking to share enjoyment, interests, or achievements with other people (e.g., by a lack of showing, bringing, or pointing out objects of interest)

d. lack of social or emotional reciprocity

(2) qualitative impairments in communication as manifested by at least one of the following:

a. delay in, or total lack of, the development of spoken language (not accompanied by an attempt to compensate through alternative modes of communication such as gesture or mime)

b. in individuals with adequate speech, marked impairment in the ability to initiate or sustain a conversation with others

c. stereotyped and repetitive use of language or idiosyncratic language

d. lack of varied, spontaneous make-believe play or social imitative play appropriate to developmental level

(3) restricted repetitive and stereotyped patterns of behavior, interests, and activities, as manifested by at least one of the following:

a. encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus
b. apparently inflexible adherence to specific, nonfunctional routines or rituals

c. stereotyped and repetitive motor manners (e.g., hand or finger flapping or twisting, or complex whole-body movements)

d. persistent preoccupation with parts of objects

B. Delays or abnormal functioning in at least one of the following areas, with onset prior to age 3 years: (1) social interaction, (2) language as used in social communication, or (3) symbolic or imaginative play.

C. The disturbance is not better accounted for by Rett’s Disorder or Childhood Disintegrative Disorder.

 

Diagnostic Criteria for 299.80 Asperger’s Disorder

[Note from Tim: Items A through F have to be true.]

A. Qualitative impairment in social interaction, as manifested by at least two of the following:

1. marked impairment in the use of multiple nonverbal behaviors such as eye-to eye gaze, facial expression, body postures, and gestures to regulate social interaction

2. failure to develop peer relationships appropriate to developmental level

3. a lack of spontaneous seeking to share enjoyment, interests, or achievements with other people (e.g., by a lack of showing, bringing, or pointing out objects of interest to other people)

4. lack of social or emotional reciprocity

B. Restricted repetitive and stereotyped patterns of behavior, interests and activities, as manifested by at least one of the following:

1. encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity of focus

2. apparently inflexible adherence to specific, nonfunctional routines or rituals

3. stereotyped and repetitive motor mannerisms (e.g., hand or finger flapping or twisting, or complex whole-body movements)

4. persistent preoccupation with parts of objects

C. The disturbance causes clinically significant impairment in social, occupational, or other important areas of functioning.

D. There is no clinically significant general delay in language (e.g., single words used by age 2 years, communicative phrases used by age 3 years).

E. There is no clinically significant delay in cognitive development or in the development of age-appropriate self-help skills, adaptive behavior (other than in social interaction), and curiosity about the environment in childhood.

F. Criteria are not met for another specific Pervasive Developmental Disorder or Schizophrenia.

Notice that the major differences between autism and Asperger’s are the lack of speech delay and certain developmental skills (item E) in persons with Asperger’s. From people I’ve talked to, it’s usually the speech development that people notice most readily in classifying someone as Asperger’s rather than autistic.

Then there’s PDD-NOS, or what some call, “Heck-If-We-Know?”.

299.80 Pervasive Developmental Disorder Not Otherwise Specified (Including Atypical Autism)

[Note from Tim – Yes, the codes for Asperger’s and PDD-NOS apparently are the same, and no, I don’t know why. They aren’t considered the same ‘condition’.]

This category should be used when there is a severe and pervasive impairment in the development of reciprocal social interaction associated with impairment in either verbal or nonverbal communication skills or with the presence of stereotyped behavior, interests, and activities, but the criteria are not met for a specific Pervasive Developmental Disorder, Schizophrenia, Schizotypal Personality Disorder, or Avoidant Personality Disorder. For example, this category includes “atypical autism” – presentations that do not meet the criteria for Autistic Disorder because of late age at onset, atypical symptomatology, or subthreshold symptomatology, or all of these.

Clear? I confess it really wasn’t to us after we first read this last year. It makes way more sense to me now, but that’s with a year under our belts. Again, go read our “Five Things You Can Do If You Think Your Child Has Autism” post and the “Autism and Autism Spectrum Disorders (ASDs)” section of our Links and Resources page for information that may help make this easier to understand.

Next time, less jargon and more J-Man!

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{ 6 comments… read them below or add one }

Ecki February 20, 2009 at 12:42 pm

My older daughter has a PDD-NOS diagnosis and I hate it. It’s so vague, it’s not really a diagnosis. It’s just something so that she can receive some services in school. Personally I think the PDD-NOS criteria are so silly that just about everyone could have that diagnosis!!

Tim February 23, 2009 at 11:16 pm

I’ve been meaning to do a little digging and see whether children diagnosed with PDD-NOS encounter particular obstacles when seeking school services. When you get “Autism” stamped on your file, most of the rest of the conversation is haggling over how many services you get. I’ve been wondering whether PDD-NOS makes that conversation – like at the IEP level – a lot more challenging, or is it treated by the schools similarly to autism but perhaps with fewer services or less school hours, or what? This is an area in which I show serious gaps in my knowledge. I’d be interested in your insights.

The doctor who diagnosed our son actually refuses to give out PDD-NOS diagnoses at this age. His philosophy was essentially, “If I can’t tell you it’s autism, I’m not going to make up a label for it.” He wasn’t into that vague, gray area stuff.

I know with the DSM-V revision they’re working on (supposedly debuting in 3-5 years), the goal is to greatly refine the categories so that descriptively they make more sense and reflect the reality of what our kids are experiencing. It sounds like one of their major goals is to get rid of PDD-NOS in favor of more specific diagnoses. I’d bet the farm that the number of types of autism described in the manual will go up significantly. How they’ll come up with those ‘types’ is a task I don’t envy them at all for.

What I’m very fascinated to see is whether they really do add a severity label to a diagnosis. Right now, ‘severe’, ‘moderate’, ‘high functioning’, etc. are all essentially made-up terminology without any clinical definition. One goal of the working group is clearly to remedy that if at all possible.

I did find this link that discusses what all they are investigating; it’s an interesting read. Report of the DSM-V Neurodevelopmental Disorders Work Group

Tim February 23, 2009 at 11:17 pm

Oh, and seriously, if there’s ever a type of autism a little bit ‘higher’ up the list than Asperger’s, I bet there’s a good chance I’d fit in there somewhere.

PDD-NOS Autism March 23, 2010 at 8:23 am

Hi, Nice post :). I’m blogging about autism to, can we exchange link?

carrie April 20, 2011 at 11:46 pm

i am hearing they are taking out pdd-nos and aspergers , my son was JUST diagnosed with pdd-nos first it was aspergers and then we went to an autism clinic and they said pdd-nos and are doing a social situation test on him tuesday april 26th to see if he fits anywhere else with a more definate answer, BUT WHAT IS THIS I HEAR ABOUT GETTING RID OF PDD-NOS OR ASPERGERS/?????? CAN ANYONE GIVE ME ANY INSIGHT INTO THIS?????????????

Tim May 16, 2011 at 12:57 pm

Carrie – There has been a lot of discussion about whether Asperger’s and PDD-NOS as separate diagnoses will be dropped in favor of broadening the umbrella of autism to include them. This may end up being a good thing in that it should expand opportunities for our kids to get services (theoretically). The DSM-V (the gigantic diagnostic guide to things related to ‘mental disorders’) is under revision and will probably be released in 2-3 years. I’m not sure where autism-related revisions are at this point, though. PDD-NOS really needs to go away in my opinion because all it really means is “Your child is delayed, we don’t know what’s going on, but here’s a diagnosis. Have a nice day.” Parents and kids need something more specific than that. I am conflicted about Asperger’s possibly going away as a diagnosis, though. It’s something we fairly readily understand when it comes up in conversation, and it is an important identity for a lot of people. If the DSM people capture the important differences between autistic persons (e.g., verbal, non-verbal, or to some degree verbal) for the sake of making an accurate diagnosis for each individual person, then I think we’ve accomplished something. The overhaul of our long-standing vocabulary is going to be really confusing, however. I think the jury is still very much out on this whole process.

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