https://media.jamanetwork.com/news-item/lower-opioid-overdos...
...which declares other correlations: "cannabis use has been linked with increased use of other drugs, including opioids" again adding "however, a causal relationship has not been established." Should we assume the bad stuff is causal, too? I don't believe we should.
https://www.vice.com/en/article/ne45vd/more-vancouver-opioid...
https://mugglehead.com/vancouver-cannabis-harm-reduction-pro...
"...no consensus among studies that cannabis use is associated with reduced opioid use or longer treatment retention when used during methadone maintenance therapy"
[0] https://thehighestcritic.com/news/recreational-marijuana-leg...