Currently_Sleeping wrote:
"... However, in the past and still today, some young adults with Asperger's syndrome are referred for a psychiatric assessment for schizophrenia."
This is also my experience, and apparently common. It is especially so for people who are undiagnosed and are evaluated for the first time in adulthood, perhaps for depression or anxiety - in other words, there has often been a real change in the psychiatric presentation, but the autistic traits mislead even competent diagnosticians.
If the autistic spectrum disorder is not recognized, then it can lead to a great deal of unnecessary treatment to "return" the person to an assumed level of previous function, rather than that person's own normal.