Using Medical Marijuana: How to Stay Safe
Here is a rundown of what she suggests to the patients she works with:

If you are going to use marijuana, it’s important to work with your psychiatrist and other trusted members of your mental health team who understand the dangers of THC on people vulnerable to experiencing psychosis and who can guide you in the best way.
Understand that even if something is labeled as low THC or no-THC, this doesn’t mean it’s true since marijuana is not currently approved by the Food and Drug Administration (FDA). The only way to know how it will impact you is to actually try it, which is not worth the risk if it could lead to psychosis.
Keep in mind that just because it’s called “medical marijuana” doesn’t mean that it’s safe, whether you are consuming it as a tincture, in plant form, as a topical product, or as an edible. “Medical marijuana” is simply a name. Only testing with your own body will let you know if something is safe. (Also keep in mind that there are several FDA-approved cannabis-based medications with very restricted indications including nausea, appetite stimulation, and epilepsy, but these are not medical marijuana.)