[vacri]

Way back in the 90s when I was doing my neurophysiology degree, one lecturer who worked with schizophrenia said that it was such a difficult disease to work with because it wasn't one disease. Traditionally, if they didn't know what was wrong with you, they just threw you in the 'one-size-fits-all' schizophrenia bucket. One example of this was that the most frequent symptom (hearing voices) was present in only 69% of cases, and all other symptoms dropped off fairly quickly from there.

At the time, he thought that schizophrenia would break up into four basic groups, based on positive/negative affect (does an episode have the person doing extra activity or withdrawing) and, I think, whether or not the person has hallucinations.

I haven't really kept in touch with the literature to see how his 4-way prediction went, but I have never seen anything to counter the idea that schizophrenia is more than a single disease. And, of course, classification of disease is a key element of treating it, so if schizophrenia is not being properly classified...