In recent years, there has been a surge in research regarding marijuana use and its potential risks as well as benefits. The increased interest and support in marijuana research are also fuelled by movements to legalise weed in various countries, particularly regarding medical marijuana but also surrounding weed for recreational purposes. Having said this, there still remains contrasting research about the effects of marijuana and potential risks are noted alongside benefits. 

One of the topics of research surrounding marijuana use is its effect on memory. But what is memory, really?

Memory can be seen as our brain’s way of encoding, storing, and later retrieving information. It can be split into sensory memory, short-term memory, and long-term memory. Sensory memory is information stored from our perceptions of the world around us through the five physical senses of sight, sound, touch, smell, and taste. Short-term memory is information stored in the brain that is active and ready for use. It is available for a brief period of time and has limited capacity. On the other hand, long-term memory can store an unlimited amount of information for an indefinite period of time.

So how does marijuana interact with the brain?

Marijuana contains chemicals such as delta-9-tetrahydrocannabinol (THC), which is absorbed into the blood, through which it reaches the brain. It then binds with receptors found in parts of the brain related to memory, such as the hippocampus. 

But does this affect memory functioning?

Research has shown that short-term memory functioning can be reduced while someone is using marijuana containing THC. This can depend significantly on how frequently and heavily the person smokes as well as their age. Certain studies have found that young people and adolescents, especially those who started smoking before they were 15 years old are more prone to deficits in memory as a side effect of smoking weed. The side effects can be observed mostly in verbal memory, referring to the memory of words and other language-based memories, as well as in working memory which structures and processes information for a short period of time. Problems with recalling and retaining information, in general, could also be noted. 

On the bright side research also found that effects on memory were not permanent and were often reversed after some time when the person quits smoking marijuana. Having said this, some research indicates that heavy and long-term users may still have long-lasting damage to verbal memory, learning and concentration by middle age.

Another point worth noting is that a component of marijuana known as Cannabidiol (CBD) which is not psychoactive, meaning it doesn’t get you high, can actually combat cognitive impairment and help to maintain memory in older age.

In conclusion, there is research indicating that smoking weed may have an effect on your memory, but there is inconsistent research regarding exactly how and in which circumstances. Therefore, it would be beneficial to be aware of potential risks and to be cautious when consuming this drug.

If you think that you can benefit from professional support on this issue you can reach out here.

Lisa Scalpello is a trainee professional offering therapy sessions to clients who are experiencing struggles in different areas of life such as work, studies or relationships, that put a strain on mental health. She is trained in cognitive behavioural therapy (CBT) and acceptance and commitment therapy (ACT)

Schoeler, T., & Bhattacharyya, S. (2013). The effect of cannabis use on memory function: an update. Substance abuse and rehabilitation, 11-27.

Adam, K. C., Doss, M. K., Pabon, E., Vogel, E. K., & de Wit, H. (2020). Δ9-Tetrahydrocannabinol (THC) impairs visual working memory performance: a randomized crossover trial. Neuropsychopharmacology, 45(11), 1807-1816.