Still, more research is necessary before we come to any major conclusions. Throughout this article, we’re going to take a look at the research we have available. We’re going to weigh the pros and cons of cannabis on memory and whether or not it’s really as much of a threat as some like to claim.

Memory and the Endocannabinoid System

Cannabis consumption is able to have a direct effect on us thanks to its interaction with the endocannabinoid system (ECS). Phytocannabinoids (cannabinoids found in the cannabis plant) largely resemble endocannabinoids (cannabinoids naturally made in our body) and, therefore, are able to attach themselves directly to receptors. ¹The ECS is responsible for a number of regulations throughout our body, including memory and learning. ² Through animal models, it’s been discovered that the ECS is strictly in charge of cognition-related processes.

Evidence concerning cannabinoids and memory is contradictory, with some research finding it promotes memory and others claiming it impairs it. ³With that said, our understanding of the ECS and memory is still in its infant stages. Furthermore, because we don’t completely comprehend the ECS and memory, we can’t possibly know everything about how cannabis affects it.What we do know is that cannabis’ effects on memory have much to do with how marijuana is consumed, the dosage, and the frequency of use.

Beyond this, we also know that CB1 receptors are more prevalent for memory than CB2 receptors. CB1 receptors are located throughout the central nervous system (CNS) along with various aspects of the brain, including:

• Accumbens
• Amygdala
• Brainstem
• Cortex
• Hippocampus
• Hypothalamus
• Nucleus
• Spinal

Tetrahydrocannabinol (THC), the most abundant phytocannabinoid found in cannabis that’s responsible for psychoactivity, directly attaches itself to CB1 receptors. So, it’s safe to say that high-THC cannabis plays an important role in how marijuana affects our memory.

Long-Term Cannabis Use Associated with Memory Loss

As of now, there is plenty of evidence to suggest that cannabis can cause memory loss in the long-term. Especially when it comes to people consuming the plant while their brains are still developing.

 For example, one study found that rats who were exposed to THC before birth, not long after birth, and throughout adolescence had difficulty when it came to certain learning and memory tasks in their adulthood.5 More particularly, other studies found that rats were most affected by structural and functional changes in their hippocampus.6It’s worth noting that THC was found to alter a rat’s reward system. So much so that they took opportunities to administer other drugs (i.e. heroin) when the opportunity arose. This is largely where the claim that cannabis is a “gateway drug” came from.

While there’s only so much research, current evidence suggests that humans who are exposed to THC during developmental years aren’t as affected as rats. Furthermore, there’s no clear indication that these changes are adverse.7In one study, 4,000 young adults were tracked for 25 years (until they were mid-adults) to determine how cannabis affected them. The study found that while cannabis had a significant impact on verbal memory, there was no evidence to suggest it reduced other cognitive abilities, such as executive function.8There’s also been an association with cannabis use and loss of IQ points. However, the evidence for this is weak.

Most notably, those who used cannabis during adolescence and went on to develop a cannabis use disorder throughout adulthood tended to have lower IQ points. In one study, it was found that individuals as such ended up losing 6 to 8 IQ points that could not be recovered even if marijuana use stopped.9 10While there is more research, most scientists agree marijuana has a negative effect on memory when used in the long-term - particularly, when use begins during adolescents. However, the exact repercussions cannabis has on memory isn’t completely understood and one study has even found it may be able to help in certain areas.

High-Potency Cannabis Has No Impact on Decision-Making

Recently, Washington State University set out to perform a number of cognitive tests on subjects who consumed high-potency cannabis flower or vaped concentrates. All the tests were performed through Zoom and all participants received their cannabis from dispensaries located in Washington. ¹¹The purpose of this study was to see how cannabis that’s legally being sold across the United States was having an impact on those purchasing. More so, it was to compare data to a similar study in which participants were using low-quality cannabis.

Similar to our above-mentioned data, this study concluded that cannabis did have a negative effect on memory. More specifically, on free recall, source memory, and false memories. However, the study also concluded that cannabis had no impact on decision-making.

Besides a placebo-controlled sober group, the researchers were attempting to ensure they interfered with participants as little as possible. When it came to the cannabis group, the only control researchers placed was ensuring that everyone was an experienced cannabis user with no history of negative experiences, such as “greening out.”80 participants were divided into four groups which were as follows:

• Two groups smoked cannabis flower with at least 20% THC in it.

• The third group vaped cannabis concentrates with at least 60% THC in it.

• The final group didn’t consume any cannabis at all.

The researchers then conducted a series of tests to see where a cannabis user’s memory stood immediately after consumption. They immediately found that when it came to risk perception and confidence in one’s knowledge (decision-making), cannabis had no effect. Not to mention, certain memory tests, such as prospective memory and the ability to remember later tasks (i.e. deadlines), also showed little to no difference.

Interestingly, data between the cannabis consuming groups didn’t change significantly despite the fact each was intaking different potencies of products. As Carrie Cuttler, WSU psychologist and lead researcher on the study, put it:“There’s been a lot of speculation that these really high-potency cannabis concentrates might magnify detrimental consequences, but there’s been almost zero research on cannabis concentrates which are freely available for people to use. I was to see way more research before we come to any general conclusion, but it is encouraging to see that the concentrates didn’t increase harms.”

Final Word 

There’s no denying that cannabis use does have consequences on memory. However, the level of those consequences still isn’t entirely understood. As we laid out in this article, there’s a lot of conflicting research which suggests that different people respond to cannabis in various ways.

Still, even with the current research, nobody in the cannabis community seems terribly concerned that their memory’s a little hazy. At the end of the day, we’re the ones who should see the largest repercussions and unlike consumption of other substances, we just aren’t seeing them.

All we can say for certain is that it’s probably best not to consume cannabis daily when your brain is still developing. But even still, there is no evidence to suggest that the damages this causes outweigh the rewards many people receive from cannabis use.