Its not that hard to believe though. When you have used something for a long while, its difficult to face the fact that you may have been doing something to the detriment of your health. I see it as a coping mechanism.

I really don't understand what the allure of cannabis is. For me, an immediate effect was a decline not only in cognitive ability but also short term memory. Like not being able to hold a thought for more than 5 seconds. How is that pleasurable? It should be no wonder long term use trends in the direction of decline. Of course, for older or termininally ill patients, the pain management benefits may be worth the trade-off, but if the choice is living with pain vs. being perpetually stoned, I think I'd try living with the pain as much as long as I can.

(FTR, I am not against legalisation, so no need to accuse me of trying to take away your drug. I just think we need to make these decisions with caution.)

Sorry I didn’t make myself clear. I think it’s entirely possible cannabis causes problems. I’m saying this study has successfully narrowed down reasonable associations to make direct cause more likely. But this also means if it is caused by another factor, we can use weed use as a signal for whatever that other factor is with high confidence. It’s multi use in that way which is helpful to establish. It shows evidence that people who are smokers of weed now either are doing damage to themselves or have potentially significant issues they need to address because something is doing damage.

It has drawbacks. No one is saying it doesn't, but now we have a gasp on them.

Like, wait until I tell you about how bad alcohol, sugar, or sleep deprivation is for you...