My grandmother was diagnosed schizophrenic when I was a kid. She took haldol, lithium, had ECT, took anti-depressants and probably a host of other drugs.
Even without the ECT she was forgetful ... most likely culprit was haldol. Everytime we went to visit she'd recite the same stories. This was well before the old-age forgetfulness that most people get.
She was NEVER violent toward people. She could get fairly agitated but she usually took it out on herself or "the dirty magazines" at the grocery store. She got arrested once for tearing up magazines that she considered inappropriate.
One of the biggest problems with this illness is the fact that the treatment can actually exacerbate the problem. Sure haldol and lithium seem to calm patients down; but if they stop taking them the backlash is worse than if they'd never taken them at all. Plus, the body builds up a tolerance for most of these drugs. If you're really interested read this book:
Mad In America
I don't have any real advice to give you. Your friend is already feeling fairly isolated and alone so if it's at all possible maybe you could try to maintain contact.
Please be sure that you are safe though.