Assessment & Research

Toward specifying pervasive developmental disorder-not otherwise specified.

Mandy et al. (2011) · Autism research : official journal of the International Society for Autism Research 2011
★ The Verdict

PDD-NOS is a social-only autism variant, so many kids lose the diagnosis under DSM-5 unless you pivot to Social Communication Disorder.

✓ Read this if BCBAs who complete diagnostic evaluations or attend IEP meetings.
✗ Skip if RBTs who only run direct therapy and never touch paperwork.

01Research in Context

01

What this study did

Rispoli et al. (2011) ran math on old case files. They looked for a pattern that could separate PDD-NOS from classic autism.

The team used a computer to sort symptoms. They checked if PDD-NOS kids had the same level of repetitive behaviors as other autism groups.

02

What they found

Ninety-seven percent of PDD-NOS files showed one clear story. Big social-communication problems were there, but rocking, lining up, or hand-flapping were mild or missing.

The data said PDD-NOS is not just soft autism. It looks like its own type.

03

How this fits with other research

Taheri et al. (2012) later tested real kids in clinic. Only 17 percent of ex-PDD-NOS cases kept an autism label under new DSM-5 rules. The new rules demand repetitive behaviors, so most PDD-NOS kids fell out.

Greaves-Lord et al. (2013) extended the idea. They found bright PDD-NOS kids often fit Social Communication Disorder instead. This gives clinicians a new home in DSM-5.

Ricciardi et al. (2006) seems to clash. They saw equal repetitive behaviors in Prader-Willi and autism kids. The gap closes when you note they studied a different genetic syndrome, not PDD-NOS.

04

Why it matters

If you write reports, be ready to explain why a child with social gaps but few stims may still need help. Keep old PDD-NOS data handy. Track how the new Social Communication Disorder label could keep services alive without an autism code.

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Pull any current PDD-NOS cases, list their repetitive behaviors, and prep a Social Communication Disorder justification if RSBs are weak.

02At a glance

Intervention
not applicable
Design
other
Sample size
256
Population
autism spectrum disorder
Finding
not reported

03Original abstract

Pervasive developmental disorder-not otherwise specified (PDD-NOS) is the most common and least satisfactory of the PDD diagnoses. It is not formally operationalized, which limits its reliability and has hampered attempts to assess its validity. We aimed, first, to improve the reliability and replicability of PDD-NOS by operationalizing its DSM-IV-TR description and, second, to test its validity through comparison with autistic disorder (AD) and Asperger's disorder (AsD). In a sample of 256 young people (mean age = 9.1 years) we used Developmental, Diagnostic and Dimensional (3Di) algorithmic analysis to classify DSM-IV-TR AD (n = 97), AsD (n = 93) and PDD-NOS (n = 66). Groups were compared on independent measures of core PDD symptomatology, associated autistic features, and intelligence. Contrary to the assumption that PDD-NOS is heterogeneous, almost all (97%) of those with PDD-NOS had one distinct symptom pattern, namely impairments in social reciprocity and communication, without significant repetitive and stereotyped behaviors (RSB). Compared to AD and AsD, they had comparably severe but more circumscribed social communication difficulties, with fewer non-social features of autism, such as sensory, feeding and visuo-spatial problems. These individuals appear to have a distinct variant of autism that does not merely sit at the less severe end of the same continuum of symptoms. The current draft guidelines for DSM-V, which mandate the presence of RSBs for any PDD diagnosis, would exclude such people from the autistic spectrum.

Autism research : official journal of the International Society for Autism Research, 2011 · doi:10.1002/aur.178