misdiagnosis's... yikes have i had them... so many.. and at one point i had a paragraph long of them and most had "NOS" at the end. in my case that meant "we get more funding if you have these. and since you dont fit under the actual dx's we will diagnosis you with them as not otherwise specified."
Now i like the NOS drink. but the NOS of dx's i didnt lol.
my very first diagnosis was autism, (i was 4yr), altho at that time my family saw it like it was a death sentence or cancer or something, and the rejected it. it kept coming back. and back. and back. and now its back and the rest got tossed. oh, and kept the actual accurate dx's that i had. but since age 4, i had been diagnosied/rediagnosed with add/adhd, depression, manic depressive disorder (when i was 7yr), generalized anxiety disorder, social anxiety disorder, agoraphobia, elective mutism, borderline intellectual functioning, bipolar nos, mood disorder nos, borderline personality disorder, ptsd, combat ptsd, ummmmm... and a lot more. but right now its autism(correct), mood disorder nos(incorrect), and depression(correct).

i have noticed that some of those diagnosing generally somehow often have a hard time pinpointing between autism, borderline personality disorder, and add/adhd (thats just in my experience and knowing a few other people with the same kind of experience).
and at one time a really long time ago, those children who had autism at that time would be diagnosed with childhood schizophrenia.

also another interesting fact is that treatment for mental health first started when a bunch of patients who were in state hospitals was getting sick and they were given cough mediciene and that seemed to help a few if them with their mental health symptoms. and thats how the first medications started.