Perhaps your friend should consider a voluntary inpatient program at a psychiatric health facility. Forget all the stigma associated with the “nut house”. Depending on the treatment facility, he should be able to engage in more frequent individual therapy involving a psychologist (talk therapy), also structured group based programs like cognitive behavioural therapy (CBT). Whilst there a psychiatrist would be able to closely monitor his meds and his reaction to it (drug therapy).
Should there be a risk of self harm, a psychiatric facility can provide a safe environment whilst learning how to adapt.
If he seems hesitant, arrange an appointment where he could meet some of the nursing staff, perhaps a quick tour. After having done this I felt more at ease, seeing there aren’t any padded cells, prison bars nor evil orderlies.
If he books himself in, he can leave whenever he wishes.
I hope your friend finds peace and joy in life.