Diagnosis is a medical term for a label that helps professionals communicate about the cluster of symptoms they see in a person they are treating. The criteria for making a diagnosis follow the DSM 5 Manual. As of the May 2013 publishing, Asperger’s is no longer a specific diagnosis. The behaviors, challenges, and symptoms still exist for an individual but will no longer be medically labeled Asperger’s.
Asperger’s isn’t the only diagnosis that changed- all the autism diagnoses changed with the new edition of the DSM. Instead of there being several autism related diagnoses (autistic disorder, Asperger’s disorder, childhood disintegrative disorder, and pervasive developmental disorder not otherwise specified) there is now one diagnosis called autism spectrum disorder or ASD. According to the American Psychological Association, this will help to more accurately diagnose all individuals showing the signs of autism.
For more information about these changes see the Autism Society’s response to the change.
If you want a history of the change and opinions from both sides- this is a great news article from Slate.