In the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III), SDD was opposed to the pervasive developmental disorders (PDD). There were two factors that were considered:
- The specificity of the impairment: in SDD there is one single domain that is affected, whereas in PDD multiple areas of functioning are affected.
- The nature of the impairment: development in SDD is delayed but not otherwise abnormal, whereas in PDD there are behavioral deviations that are not typical for any developmental stage.
In the fourth edition of the DSM specific developmental disorders are no longer grouped together. Instead they are reclassified as communication disorders, learning disorders, and motor skills disorders.
Read more about this topic: Specific Developmental Disorder