How did the DSM-5 change the classification of autism spectrum disorder compared to the previous edition?

The DSM-5 changed the classification of autism spectrum disorder (ASD) by combining four previously distinct disorders—autistic disorder, Asperger’s disorder, pervasive developmental disorder not otherwise specified (PDD-NOS), and childhood disintegrative disorder—into a single category called ASD. Additionally, it streamlined diagnostic criteria by collapsing separate areas of impairment into a single category of social/communication deficits and removed language delays as a criterion.

In the DSM-5, autism spectrum disorder (ASD) is classified under one umbrella term, which includes what were previously considered separate disorders: autistic disorder, Asperger’s disorder, PDD-NOS, and childhood disintegrative disorder. This change reflects a more unified understanding of the spectrum. Furthermore, the DSM-5 revised the diagnostic criteria by merging social communication and interaction deficits into a single area, simplifying the diagnosis. The previous requirement of language delays as a diagnostic criterion was removed, acknowledging that such delays are not exclusive to ASD and do not apply to all individuals on the spectrum.