It is called Schizo-affect disorder. it is the higher level of Bi-polar disorder, so of a maxed out version when the mania and brain speed is so 'kindled' or hyperactive that you can see things and hear voice and yet not be schizophrenic. I know because that was me for five years I was diagnosed with it as a form of bi-polar disorder. I have been off all anti-psychotic meds now since 1997 and take nothing but something for insomnia and am sober as well. But besides multiple medications related to bipolar disease I was on Thorazine for the hallucinations from 1991 through 1996. It is not BOTH. Schizophrenia doesn't just appear one day. here is some information:
https://www.mind.org.uk/information-support/types-of-mental-health-problems/schizoaffective-disorder/about-schizoaffective-disorder/
Yes, some people with bipolar disorder have hallucinations and hear voices. Voices aren't really fully schizophrenia. https://www.healthline.com/health/bipolar-disorder/bipolar-hallucinations Schizophrenia follows a pattern different than bipolar. Are you trying to decide which is going on for your son or does he already have a bipolar diagnosis?