An Examination of the Proposed DSM-V Criteria for ASD

Background:

The DSM-V, currently in development, proposes one diagnosis of Autism Spectrum Disorder (ASD), which will include individuals currently diagnosed with Autistic Disorder, Asperger’s Disorder, Childhood Disintegrative Disorder, PDD-NOS. Instead of the previous 12 criteria , 4 each in the “triad of impairments”, the criteria are reduced to 3 social-communication difficulties and 4 repetitive behaviour/interests criteria, based on research suggesting the social and communication items load together and are distinct from repetitive actions, speech, use of objects, and sensory issues.

Objectives:

The purpose of this study is to report on an initial examination of the proposed DSM-V ASD criteria in relation to: (a) the DSM-IV criteria; (b) autism severity; (c) cognitive level; and (d) adaptive behaviour level. We hypothesized that all children previously diagnosed with AD or PDD-NOS would meet criteria for ASD under the DSM-V criteria.

Methods:

The data for this study were based on a retrospective file review of 131 children (3 to 13 years old), previously diagnosed with Autistic Disorder (n=93) or PDD-NOS (n=38). A checklist was developed consisting of the 7 items from the proposed DSM-V criteria. An experienced psychologist, who had originally diagnosed the children using DSM-IV, rated each of the 7 criteria on a 3-point scale (fully met, partially met, not met).

Results:

Contrary to our prediction, results indicated that only 63.4% of the sample met the DSM-V criteria for ASD; 91.6% of children with AD and 8.4% of children with PDD-NOS. The ASD met group had significantly higher autism severity on the CARS; lower Full scale IQ, Nonverbal and Verbal IQ, and lower adaptive behaviour scores on all domains. However, the age did not differ between the two groups.

 The 7 specific criteria for ASD were examined to determine the number of children who fully met, partially met, or did not meet each criterion. In the social-communication domain, over 80% of children met each of the 3 criteria. For the domain of restricted, repetitive behaviour only 20% of children met the criteria for two items “excessive adherence to routines... or excessive resistance to change” and “highly restricted, fixated interests” but over 70% met the other two criteria (stereotyped behaviour and hyper-or hypo-reactivity to sensory input). 

Conclusions:

Age did not differ between the ASD and non-ASD groups, suggesting that the criteria were equally sensitive for both younger and older children within the age range studied. However, the ASD group were significantly lower on cognitive and adaptive levels, suggesting the new criteria are sensitive in identifying autism in lower functioning children, but may be missing autistic symptomatology as manifest in more capable children

This study reveals that the new criteria, at least as implemented in this study, may have low sensitivity in less impaired children which has significant implications for both research and clinical practice. The findings imply that the proposed DSM-V criteria, if they remain as is, could result in many children who should receive a diagnosis being missed.