I don't blame you for feeling so skeptical about the medical benefits of marijuana. Most of us have formed opinions about marijuana based on decades worth of negative cultural impressions and government propaganda.
What's only now coming to light, is that there are a great many medical uses for marijuana, and that research confirming this, has been quietly going on for decades.
I base my distrust in marijuana on teenagers I knew that started smoking and became mentally lazy, unmotivated, and drop out.
I am not sure what percent of kids have anti-motivational problems but not trivial.
Reactions to a drug is variable and close supervision necessary imho..
Personal belief is there are many types of PTSD, not one solution for all.