I have been there with one child who I did have to get into a hospital and was able to because they had expressed suicidality. It is true they can leave after 3 days unless the hospital goes to court. Luckily mine stayed.

I have two friends dealing with adult sons in very similar situations to yours.

It is encouraging that your son was willing to try meds, but not sure those were the best ones. For example, he might need Lithium or a mood stabilizer like Lamictal. Without those a person with bipolar can become worse on an anti-depressant. If he has paranoid schizophrenia that would seem to indicate a need for an anti-psychotic. And so on.

I am not suggesting any of these disorders or diagnosing, just saying that med choices are important and need to be tailored to what is actually wrong. Hospitals are the best for that but it can be done outpatient. Any chance he would see another psychiatrist?

Sending a loving card or text or whatever once a month worked for me for awhile. I think that was a good suggestion. NAMI helps some too.