Vitamin B3, aka niacin, is known to have positive effects on mood, so can be taken as an antidepressant. It is used by many doctors also as a therapy for people with schizophrenia. But it has many other uses. I personally take it because I found it helped me get out of bed in the mornings without pain. Previously, I had got out of bed very slowly and awkwardly. Now I jump out of bed.