Regarding cognitive issues, the meta I've personally taken away is that, yes, there is some legitimate concern for permanent cognitive issues regarding pre-adul

Regarding cognitive issues, the meta I've personally taken away is that, yes, there is some legitimate concern for permanent cognitive issues regarding pre-adult usage of marijuana. However, for adults, my "gut feeling" (based on knowing some people who regularly consumed what I consider a modest amount of marijuana) is that if you aren't really heavy on your usage, you don't have much to worry about cognitive wise. Chronic heavy users, of course, may run into issues. Unfortunately it's difficult to conclude much beyond "gut feeling" because data wise, the studies on long term effects are all over the map. See this evidence based review --https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3037578/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3037578/ I get the impression that the data just isn't too good right now. You can look up one study, but you can then look up another with a different conclusion. Part of the problem I'm sure is that the illegal nature of marijuana makes experiments difficult to conduct, and will introduce a bias in the population researchers are working with that they have to be careful to control out. Alcohol incidentally also has significant cognitive concerns for pre-adults, while not being a real issue for moderate adult drinkers. Strictly enforced age restrictions mitigate this issue to some degree. (Prohibition of alcohol was tried for a while, but it didn't work too well.)