Does Using Cannabis Make You Forgetful?

Here’s what we know about their relationship.

Does Using Cannabis Make You Forgetful?
Photo by Alexas_Fotos via Pixabay

Often, the charges against cannabis users are tied in with the usual stoner clichés: laziness, poor work ethic and reduced memory function. In this article, we will discuss some emerging research on the topic working memory and cannabis, finding out once and for all what cannabis use does to our memories.

New Evidence And Old Ideas

Cannabis use dates back thousands of years, yet it’s use, cultivation, and sales have been less than legal for much of the last century. While untold thousands have been arrested, several billions of dollars have been collected through the legal system.

What’s worse: along the way, through drug violence many have died.

The resulting psychosocial process commonly revolves around a specific idea with an outsize (more influential than it should be) pretense. Such is the concept of ‘Reefer Madness.’ Something rare, when given the scope of worldwide interaction with a product or good like cannabis. Yet, when an experience is awful or conflated, it tends to stick out in the mind of those who experience it is.

As marijuana became more popular in the years leading to the Marijuana Tax Act of 1937, so too did public misunderstandings of the plant. Ideas of madness and paranoia began to percolate around the subject of marijuana, and it was tacked on that significant impairment of memory was from cannabis.

Back then, media didn’t move as fast as it does now, and it was scientifically valid to blame mothers for schizophrenia.

The point is, times have changed. With more and more state legalizing cannabis after 80 years of prohibition, it is time to employ some of the advances in technological and scientific understanding to gain perspective.

True: memory and reaction time are statistically correlated to cannabis use.

False: memory retrieval gets worse with cannabis use.

What Is Working Memory?

Working memory is a lot like the RAM memory of a computer. It does not mean information has been hard-coded into our memory. Instead, working memory implies a near-term function, where maybe only seconds to days have passed.

On the topic of working memory and cannabis use, one recent study in sticks out in particular. The study observed 75 participants, 60 of which have used cannabis while 15 had not. The objective was to determine whether the age of onset – that is, when in an individual’s life they first used cannabis – is related to working memory reaction time.

Working memory reaction time was measured using a system of cues and responses which imitated the typical functioning of memory in our environment. With regard to memory and cannabis use, the series of cues made by researchers additionally evaluated the following:

Memory Encoding: This was evaluated by showing one or three stimuli to be recollected.

Memory Maintenance: Using advanced imaging technology (fMRI), memory maintenance was evaluated by showing where the information was held and maintained in the brain.

Memory retrieval: This was measured by showing four stimuli and evaluated by matching cues to the previous stimuli.

As the main focus of the study was to determine if the reaction time of an individual’s working memory relates to cannabis use IF exposed during adolescence, the true results of the study provide evidence that cannabis and memory have a highly variable, if not totally illogical, relationship.

The Results

By using a fMRI scanner, researchers were able to show the parts of the brain which are most active when supplied with the encoding, maintenance, and retrieval stimuli. As was consistent with previous research, the areas of the brain researchers focused includes the posterior parietal cortex (PPC) and dorsolateral prefrontal cortex (DLPFC), which help regulate executive function and control in the near-term.

The results found three relationships regarding working memory and cannabis use worth noting.

First and most unfortunately, research reinforced the idea that individual’s who began using cannabis earlier in life had longer reaction times than both cannabis users who began using after adolescence and non-users. This suggests broadly that cannabis use may impact the development of encoding information if used early in life.

(Note: this does not mean cannabis use is a predictive factor for memory issues, rather working memory and cannabis use may have a relationship.)

Second, the age an individual first uses cannabis and whether they have used cannabis once or repeatedly had no relationship on the behavior of the brain. According to researchers, this may suggest the age a person initially uses cannabis may reflect substance use risk characteristics rather than a cannabis-exposure effect (such as impaired memory) on brain development.

And last but not least, among the group of 75 participants, the researchers were able to show repeated cannabis use AND greater levels of overall cannabis use were associated with increases of performance in the activation (i.e. – working of) of the dorsolateral prefrontal cortex (DLPFC) during the maintenance period

Cannabis and creativity? Check out this strain.

Additionally, across all 75 participants, users of cannabis generally performed better than non-users, which includes a faster reaction time and higher memory retrieval accuracy.

Joey is a freelance writer, Board-Certified Pharmacy Technician (CPhT), cheesemonger, and digital marketer based out of Denver, Colorado. He has been a contributing writer in the cannabis industry for nearly two years. In his time in the cannabis space, he has written on economics, taxes, regulations, law, and medical or scientific research. Read more of his work here.

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