>>13650180>without using any drugs>>13649962OP your best bet will be extensive isolation as fpbp said, and also add to that sleep deprivation. Sleep deprivation will fuck your brain up at an astounding pace. My theory is the main reason meatheads tend to be so erratic is largely because they regularly stay awake for so long, not just because the drug itself is frying their receptors (although that is a huge part of it).
A third thing that has a detrimental effect on mental state is environment. Changing location regularly, sleeping in a different place every day, bonus points if its somewhere both uncomfortable and unsafe, for example under a bridge, or behind a building in an unfamiliar location. This will gradually erode your psyche somewhat.
Basiclly, living like a homeless drug addict, minus the drugs, would probably be the most effective way to become schizo (or something like it). The main factors will be high stress (high cortisol), and deprived sleep, compounded by isolation.
