which is in contrast to several other studies done with weed over the years.
Every article I have read on this claims that there is insufficient evidence to prove any serious long-term effects. Either that or it says things like "increases the risk" psychosis, alzheimers etc. But by how much? Eating fatty foods increases your risk of heart disease, drinking alcohol increases your risk of liver failure, artificial sweeteners increase your risk of cancer (although if you have sugar instead that can also cause cancer/make you fat and in turn cause heart disease etc.).
Are we really supposed to stay away from all these things just because they might "increase our risk" of getting a disease by an unknown amount? As long as you don't go overboard and have too much of any of them then you should be fine.
That's my thoughts on the matter anyway.