First I am not a doctor. But telling you what my docs said. Psychosis is a condition which can be caused by more than one thing. Before starting anti psychotic your doctor should eliminate other possibilities. There are auto immune diseases which can cause hallucinations which can be misdiagnosed as Sz or bipolar (http://neurosciencenews.com/schizophrenia-immune-disorder-bipolar-8179/). Your doctor does blood test, and MRI scans to check which is the condition. Unfortunately there are no tests for sz yet but progress is being made on that (eg :Progress towards a brain scan for diagnosis). But there are tests that can eliminate possibilities that you might have one of other conditions.
Talk about these with your family and docs and then decide the course.
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