According to Renee A. Alli, MD,
“High-functioning autism” isn’t an official medical term or diagnosis. It’s an informal one some people use when they talk about people with an autism spectrum disorderwho can speak, read, write, and handle basic life skills like eating and getting dressed. They may live independently, and are a lot like anyone else.
For a long time, however, only people with very severe symptoms were diagnosed with autism. Starting in the 1990s, milder forms were recognized, including high-functioning autism and Asperger’s syndrome, which share many of the same symptoms.
Then in 2013, the American Psychiatric Association grouped the autism-related disorders into one term: autism spectrum disorder, or ASD.