Strange. I had that happen to me once after drinking black cohosh tea. I bought the herb in a natural foods store, made the tea, drank it, and experienced absolutely uncontrollable laughter. Sounds funny, but it is not funny, at all. I was lying on the floor, couldn't stop laughing. My ribs were aching, but I couldn't get control of my emotion. I've never been on Rexulti, but your reaction sounds much like mine with the black cohosh. If it happens again, I would definitely tell your pdoc.