Recent studies on autism concern the number of individuals diagnosed with pervasive developmental disorder (PDD) according to DSM-IV-TR who may no longer qualify for diagnoses under the new DSM-5 autism spectrum disorder (ASD). ASD is diagnosed using the impairments in two dimensions:

– the social and communication dimension;

– the restricted and repetitive interests and behaviors (RRIB) dimension whereas PDD is diagnosed using impairments in three dimensions.

All the studies indicate between 50 and 75% of individuals will maintain diagnoses.

The aim of the study is to quantify how many individuals with previous PDD diagnoses under DSM-IV-TR criteria would maintain a diagnosis of ASD under DSM-5 criteria.

Our sample consists of 23 cases (21 males, 2 female) related to the treatment Centre “Una breccia nel muro” of Rome and Salerno. All the cases previous received a PDD diagnose according to DSM-IV TR criteria. The mean age of cases was 7.7 years. All the cases were diagnosed by our team according to DSM-5 criteria, clinicians also used to make diagnoses: the Autism Diagnostic Observation Schedule-2, the Autism Diagnostic Interview-Revised.

Eighty-seven percent of cases with PDD were classified as ASD using DSM-5 criteria. Thirteen percent of cases, that previous received an Asperger diagnose, did not meet the ASD criteria (Fig. 1).

DSM-5 criteria may easily exclude cases with high functioning from ASD because they tend to be atypical for ASD according to this study.

The authors have not supplied their declaration of competing interest.