Not exactly, but they lumped a bunch of symptoms together that often weren't really psychosis at all. Autism used to be known as childhood schizophrenia. DID often involves hearing alters' voices and having the "delusion" that you are someone else, so that was often misdiagnosed as schizophrenia, especially since it often results from sexual abuse/trauma and back in the day, it was thought that that almost never happened and women made it up because of their Freudian fantasies. PTSD can involve hallucination-/delusion-like flashbacks, hypervigilance that borders on paranoia, etc. Epilepsy (especially temporal lobe epilepsy) can still be mistaken for psychosis today.

The other diagnosis that lumped together a bunch of unrelated disorders/symptoms back in the day was hysteria (another diagnosis DID patients got stuck with), but I won't even go into that... so much pseudoscience and sexism that I can't even...