When my MIL would go off her meds, it was awful. My FIL had to get a court order to get her into a hospital to regulate the meds and to keep it going. It took a lot of $$$$ and a lot of time.
In New York state it takes two psch. to commit someone to a hospital against their will. My mother has a very high IQ and she would convince the doctors their was nothing wrong with her, this was like 40 years ago. Later when she had a history it was not as difficult. Yes lots of time and money. I learned to detach at an early age.