cbd oil memoryDecember 15, 2021
Different ratios of these two chemicals are found in various types of cannabis. Consuming a cannabis product with THC but no CBD increases the risk of developing mental health problems, such as psychosis. However, CBD could actually be used to treat psychosis.
However, using cannabis later in life (age 50 and over) appears to have only a moderate impact on cognitive functioning, including on memory. These modest declines are not fully understood, and there is a lack of high quality research in this area. That will need to change as it’s not just young people that use cannabis. As more countries legalise cannabis, older people might also want to try it.
University of Leeds provides funding as a founding partner of The Conversation UK.
Cannabis with higher levels of THC and lower, or negligible, amounts of CBD appear to have a detrimental effect on short-term memory, particularly in adolescents. The main problem is their ability to retain and recall information. Fortunately this is not permanent.
These apparently paradoxical effects from the same drug are best explained by two chemicals found in cannabis. Namely delta 9-tetrahydrocannabinol (THC) and cannabidiol (CBD). We all have naturally occurring cannabinoid receptors in our brains. THC is able to effectively bind to these receptors, creating euphoric effects. However CBD can interfere with this binding process, which dampens the feeling of euphoria.
Frequent cannabis by teens may impact their memory and ability to concentrate. mooremedia/ Shutterstock.
The Conversation UK receives funding from these organisations.
Memory is divided into both short-term and long-term memory. Short-term memory is where immediate events are temporarily stored, whereas long-term memory is where information is stored indefinitely.
Current evidence shows that cannabis intoxication may temporarily alter or distort short-term memory processing. This seems to be caused by compounds in cannabis that disrupt neural signalling when binding to receptors responsible for memory in the brain. Interrupted short-term memory can indeed impact on learning, and may also cause loss of interest or problems with concentration.
New research also suggests that it’s cannabis, rather than alcohol, that’s responsible for damage to developing teen brains. Though alcohol can destroy or severely damage brain neurons and their signalling functions, this study showed cannabis actually changes the neural brain tissue responsible for memory. But this change can be reversed within a matter of weeks if a person abstains. Though surveys suggest fewer young people are using both cannabis and alcohol, those teenagers that do use cannabis use it twice as frequently.
Recent research even suggests that any memory impairment associated with using cannabis can be reversed when people stop using cannabis. This effect was seen mainly in those who used cannabis at least once a week.
However, early research also shows that cannabis could have a positive impact on neurodegenerative diseases that affect memory, such as Alzheimer’s, Huntington Chorea, and epilepsy. In mainly animal studies, when researchers used components found in cannabis, they found it could slow or even prevent the advance of these diseases – essentially through the creation of neurons.
And while there’s little doubt that some people who use cannabis do experience impaired memory, establishing that cannabis is the cause is tricky. One reason for this is because it’s difficult to rule out the impact of other drugs that people may have used – and whether these drugs contributed to this memory impairment. For example, alcohol misuse can also cause brain damage and memory loss. Another obvious problem when researching this is when asking people with impaired memory to recall their past drug use and any associated problems. Their ability to recall these details could be compromised.
Cannabis use has long been associated with memory loss. But until now, this notion was largely anecdotal. As researchers begin to look into cannabis and the effect that it has on human health, they’re beginning to better understand the effect it has on the human brain – and whether cannabis really does impair memory.
University of York provides funding as a member of The Conversation UK.
Just as higher doses of alcohol can potentially cause brain damage, higher doses or more frequent use of cannabis may also cause long-term memory problems – the ability to learn effectively and the ability to concentrate on a task for example. Some people will use both alcohol and cannabis, often at the same time, which may both worsen the potential impact on memory.
Research shows that young, frequent users of cannabis have thinner temporal and frontal cortices, which are both areas that help process memory functioning. Memory is a critical aid to learning and study – but cannabis doesn’t just effect memory, it can also reduce motivation to learn. This dual influence reduces a young person’s engagement in education and their ability to perform.
Elizabeth Hughes receives funding from National Institute for Health Research.
But these recent discoveries about the role of THC and CBD in cannabis show that we can no longer simply say cannabis itself causes psychosis, or is detrimental to memory. Rather, it might be the type of cannabis, and the compounds it contains, that may have specific risks or benefits.
Ian Hamilton does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
While there is likely to be no great harm to a person’s memory if they experiment with cannabis, current research seems to agree that the more frequent the use, the greater the risk. Though there is still a lot that researchers don’t yet know about cannabis use on memory, current evidence suggests that any memory impairment can be reversed if a person abstains from use.
The laws regarding marijuana differ from state to state. Some outlaw it altogether, while others allow it for medical purposes—to help relieve pain and nausea, for example. And in a growing number of states, marijuana is legal for recreational use. But it remains illegal at the federal level. For that reason, it has been difficult for researchers in the United States to obtain federal research funding to study marijuana, limiting the amount of high-quality evidence available.
Cannabis contains varying amounts of the potentially therapeutic compound cannabidiol (CBD), which may help quell anxiety. However, there’s no question that marijuana (the dried flowers and leaves of the cannabis plant) can produce short-term problems with thinking, working memory, executive function, and psychomotor function (physical actions that require conscious thought, such as driving a car or playing a musical instrument). This is because marijuana’s main psychoactive chemical, THC, causes its effect by attaching to receptors in brain regions that are vital for memory formation, including the hippocampus, amygdala, and cerebral cortex. The extent to which long-term use of marijuana (either for medical or recreational purposes) produces persistent cognitive problems is not known.
As you get older, certain aspects of memory normally decline, but that does not mean you are powerless to protect your brain as you age. In fact, there is a lot you can do. In addition to getting regular exercise and eating a Mediterranean style diet, you can also consider what is known and not known about marijuana.
Is weed bad for your brain?
What you can do: If you use marijuana, understand you may have problems with memory and related cognitive functions while under the influence. There also is the possibility of developing cognitive problems with long-term use.