Sadly, long term pot use has been linked to losing as much as 10 IQ points over a decade. With the rise of pot use significantly correlated with the rise in Leftism in the US (my assertion but the timeline sure seems to click) perhaps it's more than an a coincidence.
Here is one such paper on the pot use so the morons can't cry about me making stuff up.
https://neurosciencenews.com/cannabis-cognition-19945