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.