> I’m really worried about the subset of the population with preexisting mental disorders such as manic depressive disorder, schizophrenia, and depression who will suffer a psychotic break from the use of these substances.

I honestly don't think we have the capacity to test existing psychiatric medication to the extent that we can provably demonstrate that over the long term, psychiatric medication + negligence (or simply, variance - controlled lab conditions versus real world) in mental health care is not a direct cause (more nicely, a contributory factor) of psychotic breaks for patients.

So yes, it's a risk, but it's not one that doesn't currently exist with what we do now.