[x86ARMsRace]

This comment really is at odds with a lot of current research, especially with respect to harm reduction and medical usage.

The exact opposite of your theory is pretty clearly demonstrated in the medical literature with respect to risk escalation. Cannabis use is correlated with reduction in mortality rates, and lower frequency use of hard drugs in chronic substance abusers. It facilitates a risk deescalation for hard drug users.

Literature does indicate that those abusing a substance are more likely to abuse other substances, however there is consensus that there is no gateway effect. Essentially, there's no way to determine causality in these situations, as poly-drug addiction is a complex illness. Lastly, these results were for people who's use disorder escalated to the point where they were checked into an inpatient care facility. That's not the type of quasi-medical use you describe.

See, for instance:

https://onlinelibrary.wiley.com/doi/abs/10.1080/095952399967...

https://www.sciencedirect.com/science/article/abs/pii/S15265...