There is so much wrong here… A tiny sample size, non-random group selection, short duration, no real control group (overall diet and intake of other substances were not controlled for). The self-selected group regularly smoking marijuana is bound to be substantially different from a self-selected group not smoking at all in many other respects, starting from previous history of substance use and ending with different current habits and routines.
And, of course, the authors already knew what conclusions they’d like to see. Makes one wonder how many similar studies were conducted and subsequently quietly buried because the results didn’t fit the desired narrative.
