With the low sample size of the study, I wonder how much of that is confounding variables. I know when I’ve been at my heaviest cannabis usage, my life was falling apart and I was using it to cope with a shitload of stress — which is known to cause short-term and working memory impairments.

Then you’ve also got, say, ADHDers (diagnosed or otherwise). We’ve literally got dogshit working memory disorder and as a population we tend to love substances (on account of the underactive reward circuits in our brains).