Cannabis & Memory: The Evidence Behind Marijuana’s Impact on Forgetfulness

Though the idea of the dumb, unproductive stoner is still steadily phasing itself out of the cannabis conversation, unfortunately, there is still a lot of conflicting information when it comes to cannabis and memory.

The average person with a working knowledge of how weed works is often led to believe that consuming it can lower your IQ and deplete your memory, regardless of how much or how often you partake. But there is evidence that shows that there is much more to consider, including the strain of weed you’re smoking, whether or not it’s THC– or CBD-dominant and the amount of time you have been consistently smoking — and that’s just for starters.

It’s also important to consider that there are different kinds of memory. For the purpose of research, most studies focus on short-term memory (also known as working memory) and long-term memory, which includes implicit (unconscious) and explicit (conscious) memory. THC, the most well-known cannabinoid in cannabis, is what can have an impact on both long-term and short-term memory.

THC vs. CBD

Most studies, like this one from JAMA Internal Medicine, offer research confirming that “long-term heavy cannabis users show impairments in memory and attention that endure beyond the period of intoxication and worsen with increasing years of regular cannabis use.” But there are others, like this one from a medical journal called the Neurobiology of Learning and Memory, that suggest that “acute exposure” to cannabis can actually help enhance working memory performance.

In another study published in a journal called Addict Biology, researchers examined the relationship between memory function and cannabis consumption and found that “that sustained moderate to heavy levels of cannabis… do not change working-memory network functionality.”

Conversely, CBD has been shown to be a neuroprotectant that has the potential to prevent the onset of conditions like dementia and Alzheimer’s disease, illnesses have forgetfulness and a decline in memory as a common symptom.

In fact, a recent study found that “CBD was able to reverse the deficits in both objection recognition memory as well as social recognition memory without impacting the body’s anxiety parameters.” The research also showed that CBD could reduce cognitive deficits.

In Conclusion? It’s Inconclusive

If it all seems like a confusing jumble of contrary data to you, you’re not alone. The truth is that there is still a lot of research that needs to be conducted in order to paint a clear and distinct picture of how cannabis truly affects memory.

In most studies, participants (including the rats) are not even allowed to smoke cannabis. Instead, they consume concentrated or even synthetic versions of THC — which absolutely affects the outcome. Because cannabis is still federally illegal, researchers are continuously facing hurdles that prevent them from having access to cannabis for testing and studies that would help provide a wider picture.

So, what’s the verdict? For now, it seems clear that there is a link between cannabis and memory, though there are various factors to take into consideration, including method of consumption. Is there a difference when it’s smoked (inhaled) versus when it’s eaten (ingested) or absorbed as when using tinctures or transdermal patches? No one knows yet.

But, if you start to notice a change or decline in your memory that you suspect is related to cannabis, there’s good news. Some research shows that just one month of abstaining from cannabis — a move that’s sometimes referred to as a “tolerance break” — can have a noticeable improvement on memory function. If you’re concerned or want to see if there’s a difference, try taking a break for a few weeks and observe yourself to see if there are any changes.