I used to skip most of my meds every Sunday night, and Monday I would wake up feeling better. My doctor did not want me to skip my heart meds, because they are fast acting and short lived. But my Depekote took weeks to build up in my system, and the concentration in my system only dropped slowly. If I’d taken fast acting and short lived anti-psychotics, skipping those could have been more of a potential problem.
The side effects of drugs may go away quickly, and a person may feel better immediately upon stopping them. But the untreated mental illness is building, and before very long it will be back. The mental illness will then become the problem it was before, probably with all the other problems that came along with it. And if left untreated, all the issues like finances, drug and alcohol abuse, housing, physical health, relationships, depression etc. etc will return.
I eventually was able to find a dose which was high enough to keep the mental illness in check but low enough so the side effects didn’t bother me.