Smoking Pot May Make You More Prone to False Memories

Illustration for article titled Smoking Pot May Make You More Prone to False Memories

As we’re all aware, weed makes us a bit forgetful. Say what? But a regular toke might also leave you more prone to remembering stuff that didn’t actually happen, according to new research published in the journal Molecular Psychiatry.


Top image: Brett Levin / Flickr

False memories are one of those weird quirks of our brains, and they can run the gambit from completely benign fabrications, like placing your keys in your purse, to very serious and scary fallacious beliefs, such as imagining you were chased through the forest by bloodthirsty leprechauns. Given the growing evidence that THC can interfere with memory formation, a group of psychiatrists decided to see whether false memories, too, are affected by the drug.

For their experiments, the researchers recruited 16 regular pot-smokers, and matched them with a control group, all of whom who had used cannabis less than 50 times in their lives (apparently, finding volunteers who hadn’t sparked up at all was impossible.) In a memory recall test, the participants were asked to learn a series of words. A few minutes later, they were presented with the same words again, in addition to a handful of rogue words they hadn’t seen the first time, which were either related or unrelated to the initial group.

Using fMRI to scan the participants’ brains, the researchers found that pot-smokers were more likely to react to a “lure word”—one they had never seen before but that was related to the original list—in the same manner a person would react to a word he or she is recalling from memory. The researchers attributed this to the formation of false memories. Given that all participants abstained from smoking pot for one month before the experiments, the effect was presumed to be the result of long-lasting differences in the smokers’ brains.

“Our results show that cannabis users had a higher susceptibility to memory illusions, as observed in certain neurologic and psychiatric populations, and elderly individuals,” the researchers write.

Of course, we need to bear in mind that these were lab experiments which do not address the long-term formation of false memories. And personally, I’d take those sixteen pot-smoking participants with a big grain of salt—that’s an awfully small sample size to draw statistically meaningful conclusions from. (Which, by the way, is a big reason the biomedical literature is plagued with false research findings. For those who are statistically inclined, here’s a nice breakdown of false positive results and sample sizes.)


Still, the findings are interesting, and I’ve got no doubt there are more studies on the relationship between pot and memory to come. In the meanwhile, we can all continue to live our lives, perhaps a touch more paranoid than before about whether anybody actually ordered the pizza.

On the other hand, we could all be living in a Matrix-like simulation, in which case, screw the neuroscience and grab your bong before the machines decide to take all the fun away.


You can read the full open-access scientific paper here.


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That explains a lot.