PURPOSE:

To evaluate prevalence rates of autism and autism symptomatology in toddlers using DSM-IV vs DSM-5 criteria.

METHOD:

Two thousand seven hundred and twenty-one toddlers at risk for a developmental disability participated. DSM-IV and DSM-5 criteria were applied and overall prevalence using each set of criteria was established. Groups were also compared on BISCUIT-Part 1 scores to determine if groups differed on autism symptomatology.

RESULTS:

DSM-5 resulted in 47.79% fewer toddlers being diagnosed with ASD compared to those on the DSM-IV. Toddlers diagnosed according to DSM-5 exhibited greater levels of autism symptomatology than those diagnosed with DSM-IV, but the latter group still exhibited significant levels of autism symptomatology.

CONCLUSION:

The proposed DSM-5 will result in far fewer persons being diagnosed with ASD. These results replicate findings from two previous studies, with older children/adolescents and adults. As a result of these new criteria, far fewer people will qualify for needed autism services.