Doctors used to think of Asperger's as a separate condition. But in 2013, the newest edition of the standard book that mental health experts use, called The Diagnostic and Statistical Manual of Mental Disorders (DSM-5), changed how it's classified. Today, Asperger's syndrome is technically no longer a diagnosis on its own.
PDDs are now called autism spectrum disorder. The name change came in 2013, when the American Psychiatric Association reclassified autistic disorder, Asperger’s syndrome, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified (PDD-NOS) as autism spectrum disorders.