I'll preface this by saying that in addition to being Buddhist, I'm also a licensed mental health therapist. A lot of mental illnesses are based in physical things going on in the brain and body, often as a result of trauma, sometimes genetics, a whole host of interdependent factors. The methods of Buddhism are actually designed to be used by someone who is also decently mentally stable in a relative sense. Trying to go too deeply into meditation, especially vipashana/insight meditation, but even regular calm abiding, can have very adverse effects on those with untreated mental illness.

I only mention this because we so many users coming here with this expectation of Buddhism. Yet the fact is that Buddhism is a method to permanently uproot the causes of samsara, not necessarily treat every particular manifestation of it. They didn't know much about the brain or mental illness in the Buddha's time. If one can get stabilized through a combination of medication and therapy, one is going to be able to follow the path more easily and with less risk. I also speak from my own personal experience in initially making my MH symptoms worse when I tried to use Buddhism for such a thing 10 years ago.