The issue is that it is not clear cut at all. Psychosis is a positive symptom. But by changing the neuro-transmitter balance when treating psychosis with anti

The issue is that it is not clear cut at all. Psychosis is a positive symptom. But by changing the neuro-transmitter balance when treating psychosis with anti-psychotic medication, negative symptoms can also appear. Depending on who establishes the diagnostic, you can be diagnosed as schizophrenic while you are simply in one of the phase (acute or post) of psychosis. In general, if you repeatedly suffer from bouts of psychosis, you will get a diagnosis even though the real trigger has not been established. Also, the presence of negative and/or positive symptoms differs from people to people so even that is not clear-cut.