No but schizophrenia is a difficult disorder. Sometimes, (and this isnāt always but some of the time) the paranoia means they wonāt trust anything like meds because they believe it poison due to their delusion.
I donāt want talk out of my butt, so Iāll let the facts speak. This has been studied.
https://pmc.ncbi.nlm.nih.gov/articles/PMC3782179/
Adherence will depend on many factors like social support, attitude about medication to begin with, etc.he has no support and is unlikely to succeed unless maybe he can get visiting care. He could benefit from a social worker.