Well, first of all, I don't think that psychiatry has for decades claimed that "schizophrenia is caused by refrigerator moms", even though the downfall of that

Well, first of all, I don't think that psychiatry has for decades claimed that "schizophrenia is caused by refrigerator moms", even though the downfall of that claim may have been more due to political pressure than medical research. And secondly, whether therapy does any good is a completely different question from what is causing schizophrenia - although here we are talking about triggering it rather than causing it. I have a friend who came up with schizophrenia just when graduating from university, and it was indeed devastating. But the endless therapy helps him a bit.