Concordance of DSM-5 and DSM-IV-TR classifications for autism spectrum disorder

The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) was published in May 2013. Autism spectrum disorder (ASD) has been structured for the three subtypes of pervasive developmental disorder (PDD), but the number of impairment in social and communication dimension is not stated.

The subjects were 68 children who visited the Department of Psychology and Development at Nagoya City University Hospital for the first time between the ages of 6 and 15 years old. We retrospectively re-examined the subjects using DSM-IV-TR criteria and DSM-5 criteria with two rules (two of three and one of three on the social and communication dimension) and examined the concordance rate.

Forty subjects were diagnosed with PDD, and 28 were not. The mean PDD subject age was 9.4 years, and mean IQ was 84.0 on the Wechsler Intelligence Scale for Children III or 62.7 on the Tanaka-Binet test. Twenty-seven (68%) of the PDD subjects were classified with ASD using DSM-5 criteria when the two of three rule was applied, while 32 (80%) were classified with ASD when the one of three rule was applied. All subjects without PDD were not diagnosed with ASD on DSM-5 criteria.

DSM-5 criteria may exclude high functioning and older subjects from ASD because they tend to be atypical. The diagnostic procedure for DSM-5 criteria is ambiguous, especially in high functioning subjects and those diagnosed at an older age.