What's most interesting about this article IMHO is that these results were found with "long-term cannabis users" defined as those who use "typically 1-4 times weekly". That seems like relatively casual use.
That highly depends on your frame of reference, I suppose. In most of Germany that would be considered fairly 'heavy' use already, whereas most of the West Coast would probably consider that to be rookie numbers.
I had roommates at UCSC where 1-4 times a day was a minimum.
Dude eventually quit cold turkey for a 6+ months. Also quit booze, coffee, and tobacco, dropped out of Uni and hung out at an uncle's cabin in the mountains, real Walden Pond sorta stuff. Did him a world of good, but then he got a job w/ a FAANG and went back to the "smoke two joints" routine again.
If you look at the description of the cohorts you'll find that most of the people classified as long-term cannabis users were using cannabis quite a bit more frequently than that (median ~300 days per year). It just happens that the analysis here split people into boolean subgroups rather than trying to quantify a dose-response effect (as the primary outcome; dose-response effects are claimed but not emphasized).
I would be most interested in seeing a correlation with sleep disturbances. Some cannabis users claim that they smoke weed to help with sleep disturbances; critics argue to the contrary that persistent cannabis use may cause sleep disturbances. Chronic sleep disturbances are known to correlate with a variety of negative outcomes, and the use of sleep-inducing drugs is known to correlate with a variety of problems as well (including the great boogeyman, all-cause mortality).
From my own perspective, I stopped smoking weed last year, but I don't think the overall change has been very noticeable. The use of means can distort perceptions when distributions are not symmetric. Notably, my sleep habits aren't great right now, though I'm working on it.
Author obviously has a conflict of interest. He fails to acknowledge that correlation is not causation and that these studies fail to take into account other variables that could influence the outcomes.
I don’t think you’re using conflict of interest correctly. You’re saying here the author has secondary motives, such as being sponsored by an anti-weed org or something, which they would have to disclose in their own section (as per basic academic standards).
You might want to instead if you want to criticize the research say the authors clearly have a personal agenda or bias.
I don't think they have any shortage of patients in rehab. There is already a steady stream of them. Rehab counselors are often former addicts just trying to help others live through what they did. It is not exactly a way to get rich.
I read the article and did not see anything that would qualify as a conflict. Correlation is not causation only on its face, which is why researchers compare their findings against control groups.