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Giving up marijuana improves memory in just one week, study shows

Attention rates, however, remained the same whether smoking or not.


Key Takeaways
  • 88 youngsters from Boston were recruited for the study. 55 of them managed to abstain the full 30 days.
  • Memory improved one week after abstaining, although attention rates stayed the same.
  • The researchers hope to conduct a six-month test.

According to a recently study published in the Journal of Clinical Psychiatry, if you stop smoking marijuana, your memory will improve. Real shocker here from the science community, folks!

88 teenagers and young people from Boston were recruited for the study, and offered 62 of them money to stop smoking marijuana for 30 days. Of those 62, 55 abstained for the full month, while the remaining seven probably thought they were suuuuper cooool by lying to the good folks at Massachusetts General Hospital in Boston, where the test was held.

The 55 saintly individuals who didn’t smoke were monitored as MJ-Abst, or marijuana abstinent. The 26 who continued to smoke marijuana (and the seven rascals who defied the medical community with their flagrant disregard to the law) were monitored as MJ-Mon, which sounds like it could be a Jamaican DJ, but in fact stands for ‘Marijuana Monitored’, which sounds like it could be a Canadian talk show, but isn’t.

All subjects were given weekly urine tests to see whether they were following the abstinence. Memory and attention tests took place weekly for the 30-day trial.

The study itself is most clear in its findings in this paragraph:

There was an effect of abstinence on verbal memory (P = .002) that was consistent across 4 weeks of abstinence, with no time-by-abstinence interaction, and was driven by improved verbal learning in the first week of abstinence. MJ-Abst participants had better memory overall and at weeks 1, 2, 3 than MJ-Mon participants, and only MJ-Abst participants improved in memory from baseline to week 1. There was no effect of abstinence on attention: both groups improved similarly, consistent with a practice effect.

Translated into humanspeak, this means that memory functions improved significantly after about a week for the 55 good souls who managed to eke out a full month without the devil’s cabbage, while the 26 who kept on tokin’ (plus the seven trouble-makin’ ne-er-do-wells who basically got paid to smoke weed, despite breaking the rules) saw only small improvements in memory in the tests. According to the lead researcher of the study, Randi Schuster, this could most likely be attributed to getting used to the test, reports New Scientist.

The study also means that memory quickly goes back to pre-marijuana use levels within just a couple of days of not smoking. Ultimately, this means that people can learn better when they’re not using marijuana, which is stated explicitly by Randi Schuster in a press release (which is behind a paywall):

“The first is that adolescents learn better when they are not using cannabis. The second – which is the good news part of the story – is that at least some of the deficits associated with cannabis use are not permanent and actually improve pretty quickly after cannabis use stops.”

U.S. News reports that the Boston team wants to conduct a six-month trial next, to see more long-term effects.


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