So I’m sure we have all known a “brain-dead stoner” or two, but for as many of those types out there, there are also the opposite: the highly conscious, freakishly intelligent, enlightened pot smokers. So why the difference? How do some people seem to make the plant work for them — to have both marijuana and intelligence — while others don’t? I thought this would be an interesting dichotomy to look into.
What exactly goes on up there in that brain when we consume marijuana? How does this affect pot smokers on a daily basis as well as long-term? And most importantly, if marijuana does affect intelligence, how can we make it work for us?
Well, after many haze-filled hours of deep research into the subject I can quite positively say that marijuana may just be the best darn plant to consume for recreation when it comes to conserving and even stimulating your intelligence. There are of course some helpful tidbits to know on the topic concerning how to best make it work for you — discussed in my next article — but overall you most likely aren’t damaging your long-term intelligence with a daily weed habit.
This Is Your Brain on Drugs
The most recent study I looked at on marijuana and intelligence was published in the Proceedings of the National Association of Sciences (PNAS) Journal in 2014 titled “Long-term effects of marijuana use on the brain”. This study yielded some very interesting results concerning how marijuana has the ability to increase the neural pathways in the frontal lobe of the brain — possibly increasing both traditional intelligence as well as emotional intelligence.
The most significant findings in this study reveal how regular, daily marijuana use decreases the volume of the grey matter in the orbitofrontal cortex (OFC) and the forceps minor, but at the same time alters complex neuroadaptive processes in the OFC and the forceps minor. This is another way of saying that even though marijuana decreases the amount of usable brain matter it increases brain functioning by means of increasing structural and functional connections in the nerve pathways.
According to the study,
This increased functional connectivity in users may suggest a compensatory mechanism in which greater network recruitment is engaged to compensate for the OFC liability from the marijuana use.
Now this is very interesting as the OFC is the part of the brain responsible for mental processing (thinking), decision-making, and planning. It is where our personalities are formed, it influences our brain’s responses to adversity as well as rewards, and it is linked to one’s level of empathy. This may mean that since marijuana increases the processes in this part of the brain it may cause an increase in the types of intelligence associated with these parts of the brain. Notice how stoners seem to have a lot of things in common as far as personality, levels of creativity, and non-conformist views? Hmm….
But there is one catch: the study suggests that the greatest structural-connectivity increases occurred when participants first began using pot regularly, and with chronic use over time (6-8 years) the connectivity began to decline. But users as a whole still had higher levels of connectivity than non-users, which may suggest that even long past onset cannabis use aids connectivity. Pretty cool, hey? I guess this would explain why many of the long-term users I know seem to be functioning on quite a high intellectual and emotional level, despite what anti-pot propaganda would have us believe.
Still, the study authors note that “whether evidence that exposure to marijuana leads to long-term changes in human brain structure has been equivocal” and their study doesn’t show if any effects may be reversed after discontinued use.
This Is Your Brain after Drugs
And so this is where things get interesting because there have been studies done on marijuana and intelligence and the reversal of effects after discontinued use.
Studies were published in 1999 and 2002 on the long term effects of marijuana on intelligence, and the findings are very clear: there seem to be no long-term effects of marijuana on intelligence after a period of time. And there is even evidence, though not statistically relevant, that light users had increased intelligence, which the 2014 study also found in certain circumstances.
The 2002 study “Current and former marijuana use: preliminary findings of a longitudinal study of effects on IQ in young adults” published in the Canadian Medical Association Journal (CMAJ) concluded that no long term negative effects on global intelligence (IQ) were found.
The study found marijuana use had a negative effect on IQ score in subjects who were currently smoking five or more joints per week, and that current use was significantly correlated to a decline in IQ. However, that decline wasn’t found among subjects who had previously been heavy users but were no longer smoking pot. It also found that light marijuana use didn’t significantly affect IQ. I guess this is where the increased structural and functional connections of the nerve pathways may come into play to balance the decrease in volume.
And so this study concluded that former use of marijuana does not have a long-term effect on intelligence in youth. However, its long-term effects on memory and attention remain unclear.
The 1999 study done at Johns Hopkins University had very similar findings for adults. “Cannabis Use and Cognitive Decline in Persons under 65 Years of Age” found there to be
… no significant differences in cognitive decline between heavy users, light users, and non-users of cannabis. There were also no male–female differences in cognitive decline in relation to cannabis use.
Upon completion of the studies comparing users with non-users, they found short-term residual effects of cannabis use on attention, ability to perform tasks, and on short-term memory. These effects are more severe in heavy users of cannabis as compared with light users. It also found that women had more severe short-term negative effects than men.
So there are clear findings of short-term effects on the brain, but the data shows that “over the long term cannabis use is not associated with greater declines in cognition among men, women, or heavy users.”
So there you go, when it comes to marijuana and intelligence, no findings of long-term negative effects in one study and no evidence of long-term cognitive decline in another. And I mean, we all know about the short-term stuff right? Don’t expect to remember a bunch of new names after you smoke a big fatty, obviously.
I don’t really know of any other plants used recreationally that can also make those claims. So if you are like me and enjoy altering your mental state on a regular basis but want to use a substance that has no long-term effects and only subtle short-term effects on intelligence, and may possibly even increase certain aspects of intelligence … well, evidence seems to be pointing in the direction of that enlightened plant, the queen of weeds, Mary Jane.