The Link Between Cannabis and Memory

“As CBD is lacking in psychoactive effects, it should have ZERO effects on short-term memory, long-term memory, and prospective memory (learning)” – Dr. Leah Zachar, CBD Testers scientific adviser.

Medical cannabis, while controversial, can be used as a treatment for a wide range of illnesses. Most often, an extract called cannabidiol (CBD) is utilized by being placed under the tongue, applied directly onto the skin, or is consumed like a food supplement. Unlike cannabis for recreational use, CBD oil has little to no trace of tetrahydrocannabinol (THC), the active ingredient in cannabis that gets users high.

Considering cannabis and CBD oil use as a medical treatment is on the rise, there have been questions about the long-term effects of the continued use of both. Most notably, there have been multiple studies about the impact of cannabis on memory. We’ll discuss a few key studies on cannabis and memory and why this research is important for the progression of cannabis and CBD as recognized treatments.

It’s important to note that the FDA does not recognize or approve of cannabis as a medicine, and due to federal regulation, we cannot make claims about the effectiveness of cannabis and CBD oil as medical treatments. There are, however, many other countries that have been studying the therapeutic benefits of cannabis and all of its compounds. We encourage you to thoroughly research this information and various medical treatment options.

Short-Term Memory

It’s no secret that using cannabis can have an impact on short-term memory, especially when cannabis is being used solely for recreational purposes. However, there’s a lot of debate around the impact of chronic medical cannabis use on short-term memory, and whether or not this use can have permanent effects.

In a recently published article by CNN, it’s suggested that the short-term memory loss from using cannabis typically lasts no longer than three days in adolescents and young adults. While there is no definitive argument that cannabis use doesn’t have a negative impact on short-term memory, the studies cited by CNN have shown that even chronic users, whether medicinal or recreational, suffered no permanent short-term memory loss.

The article discusses at length a study done by Jama Psychiatry. This study reviewed data from 69 cannabis studies with more than 2,100 cannabis users involved. As per the study, “Although continued cannabis use may be associated with small reductions in cognitive functioning, results suggest that cognitive deficits are substantially diminished with abstinence” (Jama).

This indicates that semi-regular use of cannabis or using cannabis as a short-term treatment may not have permanent effects on short-term memory. As CBD oil does not contain cannabinoids such as THC, the effects of CBD oil on short-term memory are far less drastic (or possibly non-existent).

Long-Term Memory

As many medical cannabis treatments are long-term, there have also been studies on the impact of prolonged medical cannabis use on long-term memory. Here, it’s important to distinguish the difference between short-term memory and long-term memory. There’s also a drastic difference between suggested permanent impacts on long-term memory and the suggestion of lasting impacts on short-term memory caused by continual use.

The distinction between long and short-term memory is found in how long it takes for the information to be forgotten, called temporal decay, as well as how much can be ‘stored’ in the brain, known as capacity limits. Short-term memory is loosely defined as information that is stored in the brain for less than a minute, and the part of the brain that stores short-term memory can hold 5-9 pieces of information at once.

Long-term memory is much more permanent and is not nearly as susceptible to disruptions as short-term memory. This is where learning is stored to be retrieved in the future. So the question is, can cannabis alter long-term memory?

A study conducted by the Institute of Psychiatry at King’s College in London reported similar findings to the short-term memory study released by Jama Psychiatry. “Relatively consistent findings have been reported regarding the acute impairments induced by a single dose of [THC] on verbal and working memory. It is unclear whether they may persist beyond the intoxication state.” The study concluded that “These findings emphasize the need for further investigations regarding the role of early-onset cannabis use on neurodevelopmental processes,” although it’s possible that 1. there is no long-term effect, and 2. users can develop a tolerance that prevents their memory from being affected by cannabis.

Prospective Memory

Cannabis and memory

A third type of memory called prospective memory has also been studied in regard to cannabis use. Prospective memory is remembering a plan, intention, or action to be taken in the future. This can involve remembering to pay a bill or return a library book. Prospective memory is important in our everyday lives.

There was a study conducted in Canada involving 150 participants, with the goal of testing the impact of cannabis use on prospective memory. The testing involved a thorough questionnaire and prospective memory test. “The results revealed no objective deficits in prospective memory associated with chronic cannabis use” (Cuttler). In fact, the study goes on further to indicate that issues with prospective memory were derived from self-reported memory problems or abuse of substances other than cannabis.

Medical Cannabis Treatments – Final Thoughts

So, what does this mean for cannabis users? Those that are using cannabis as a medical treatment may be concerned about permanent impacts from prolonged use. Well, first and foremost, these studies indicate that prolonged cannabis use is relatively safe and has little to no negative impact on memory. While more research certainly needs to be conducted, initial studies are promising, giving those with chronic conditions hope that an FDA-approved treatment may be on the horizon.