For anti-psychotic medication, you will find that if someone has a substance-induced psychosis and they have an anti-psychotic medication on board, the anti-psychotic medication won't prevent their from becoming psychotic.
Earlier in my talk I spoke about a kindling effect that occurred with substance use. As I mentioned earlier, what happens is you'll become psychotic during toxication, and that extends into sobriety, which extends into...and it becomes more severe. It actually prevents that progression from happening, and that's the benefit of it.
Also, if someone is acutely psychotic, it will help treat their acute psychotic symptoms.