A Marijuana and Memory Study: The Effects of Different Strains

Marijuana and Memory
The link between marijuana, poor memory, and cognitive afunction is as old as any drug related stigma. For decades marijuana studies confirming this link have been widely publicized and advocated by those against marijuana consumption, particularly on the developing brain. However, a new marijuana study has proposed the question of whether or not marijuana actually effects memory and cognitive ability, and if so, by how much.

Previous Marijuana and Memory Studies
But why would researchers want to perform a marijuana study about memory and cognitive ability when previous marijuana studies have already seemingly solidified the link between marijuana consumption and poor memory and cognitive function? Marijuana is not one specific plant; there are hundreds upon hundreds of strains, so any marijuana study must take into account that any conclusions reached only apply to the particular strains used. Now, marijuana is obviously an illegal substance and consuming any mind altering drug will have a universal effect on the body. But the effect of various strains of marijuana have yet to be adequately tested, some researchers believe.

Specifically, almost any past marijuana study in America, which have produced conclusions that have been applied to all strains of marijuana, were actually produced using very limited types of marijuana strains. For example, the National Institute on Drug Abuse has produced very compelling data while using very similar marijuana strains in most of their drug studies. These types of marijuana strains contain very low quantities of THC and therefore effect whatever results their corresponding marijuana study creates.

A New Marijuana and Memory Study
However, not all marijuana strains contain low quantities of THC. Furthermore, another chemical known as “cannadidiol” plays an important role in how marijuana effects the brain and in determining the quality of an individual’s memory and cognitive function. The cannabidiol counteracts the effects of THC (the effects of THC create the classic “stoner high” which include excitement either leader to euphoria or paranoia) by calming the consumer. Therefore, if a marijuana strain contains a higher level of cannabidiol, the consumer will probably be more relaxed and less hysterical.

Because there is such a disparity between the different strains of marijuana, one recent marijuana study set out to test the true difference between these strains in terms of memory and cognitive function. Is it really true that some marijuana strains will make the consumer more relaxed while others will make them more hysterical? In October of 2010, a psycho-pharmacologist from the University College of London, Valerie Curran, tested 134 marijuana study participants in order to test whether or not higher levels of TCH and cannabidiol effects the memory and cognitive ability. She allowed the marijuana study participants to smoke their own marijuana in their homes and were tested by a series of anxiety, memory, verbal fluency, and other experiments.

The Marijuana and Memory Results
She and her research team found that marijuana study participants who had smoked lower levels of cannabidiol containing marijuana, despite the level of TCH their marijuana contained, demonstrated much memory and cognitive ability loss while intoxicated compared to when they were sober. The study also suggested that no such loss of ability was demonstrated in marijuana users smoking high levels of cannabidiol. This is exciting for those in support of administering marijuana to cancer patients, as it means that while the risks of smoking still stand, there may be marijuana strains which will not strip the patients of their memory or mental prowess.


Frood, Arran. “Key Ingredient Staves off Marijuana Memory Loss: Scientific American.” Science News, Articles and Information | Scientific American. 2010. Web. 11 June 2011. http://www.scientificamerican.com/article.cfm?id=marijuana-memory.