Marijuana’s Impact on Short-Term Memory

Marijuana and memory have long been studied and still have several questions awaiting answer. Of particular focus is cannabis’s influence on short-term memory. Plainly, does weed alter it for the worse? Does it do permanent damage or does it simply provide some of the best times you’ll never remember?

The bad news is that marijuana seems to impact short-term memory in the long run, and not in a beneficial way. The good news is that this impact is the result of smoking a lot…a lot, a lot. Like an entire parking lot of herb. Thus, recreational or occasional smokers probably need not worry. Even those who smoke up on a fairly consistent basis can probably have peace of mind about this piece of their mind.

The Different Types of Memory

We know that memory is a vital part of our existence, not only allowing us to do important things (like go to work) but also allowing us to recall the tapestry of emotions and occasions that have painted our lives and made them rich and fulfilling. Memory makes us laugh, cry, and love. Simply, it’s not something we want to do without.

Humans have three main types of memory: sensory memory, short-term memory, and long-term memory

Sensory memory is very fleeting, lasting only a few seconds before it turns into short-term memory. Like the name implies, it’s memory taken in by the senses: sight, taste, smell, etc. It allows us to look at something orange and then remember that it’s orange.

Short-term memory determines which memories are dismissed and which are transferred to long-term memory. In that way, it’s like the brain’s bouncer, deciding what information gets into the nightclub and which stays outside the red velvet ropes.

Short-term memory stores information on a temporary basis; it’s what allows you to follow this article: you remember what was written above, so you understand what’s being written now. It’s also what allows you to play the aptly named board game, Memory.

Woman taking notes for memoryLong-term memory is anything that you remember from longer than a few minutes ago. It can involve memories of yesterday or two years ago or when you were four-years-old and lost your first tooth. Not all long-term memories are equal: you might remember your eighteenth birthday but not the year you turned nineteen.

Long-term memories are tied to importance as well (and, often, tragedy): most Americans recall what they were doing on September 11, 2001, but have no idea what they were doing on the tenth.

Long-term memories aren’t always constant: the mind changes and alters them, rendering them not altogether reliable – you might think your first kiss was the hot girl next door when, in reality, your first kiss was your cousin. Some things you remember as they happened; some things you don’t.

Marijuana and Short-Term Memories: What the Research Says

Short-term memories are more reliable than long-term because of the amount of time that occurs between them: moments versus months or years or decades. But, in regards to cannabis, short-term isn’t as reliable in very frequent consumers.

A study published in JAMA International Medicine found that smoking a lot of cannabis is indeed linked to damage to an individual’s short-term recall.

The research, conducted at the University of Lausanne, looked at the cannabis habits of 3,400 Americans over two and half decades. At the end of the study, the subjects took a test designed to assess cognitive abilities like focus, memory, and the ability to make decisions.

The researchers found that people who smoked on a daily basis for an extended period of time – at least five years or more – had poorer verbal memory during middle age than people who either didn’t smoke or smoked less. After controlling for several factors, including age, education level, and mental health status, the results proved significant.

This decline was dose dependent: the more people smoked, the more likely they were to experience problems

People who smoked the longest, every day for twenty or twenty-five years, had the most difficult time with the cognitive tests in regards to memory. Interestingly, the ability for people to problem-solve or stay focused wasn’t altered, not even in people who smoked daily for five years straight.Woman forgot something, no memory

But very few people smoked that much: out of the over three thousand subjects, only 8 percent had marijuana exposure of five years or more.

The researchers claimed that causation wasn’t entirely proven: it’s possible that frequent marijuana use causes short-term memory impairment but it’s also possible that those with an innate impairment are more likely to be heavy smokers.

Cannabis and Alzheimer’s

While marijuana might not be a friend to short-term memory, it’s showing promise in the fight against Alzheimer’s. According to CNN, a study conducted at the Salk Institute for Biological Studies found that THC, one of the main cannabinoids in marijuana, stimulated the removal of plaque from the brain (which is a common feature in those affected by Alzheimer’s). THC also blocked inflammation – something it’s well known for – and this blockage helped prevent damage to neurons.

Whether or not cannabis can turn into a legitimate treatment for Alzheimer’s is unknown: time will tell, it always does

But it’s exciting enough for researchers to pursue it. After all, anything that protects the brain, as THC appears to do, is worthy of another look…or several.

Everything in Moderation

There is certainly something to be said about moderation. Many things are good for you on occasion, but bad for you when you overdo it. Wine is a perfect example of this: when consumed in moderate amounts, it’s beneficial to many aspects of health (it hearts your heart, for one thing). When consumed constantly, it’s tied to diseases like cancer. Ergo, a glass is good; a bottle is not.

Cannabis may fall into a similar category; those who consume it in moderation don’t seem to have permanent damage to their short-term memory (temporary impairment, well that’s another story). And, truly, maybe everything falls into this category as well: if you consumed pounds of kale and grapes and (insert any health food here) every day for five years, they’d probably cause problems too.

Jenn Keeler

About the author: Jenn Keeler is a freelance writer and illustrator specializing in humorous lifestyle articles. She is one of the few people on earth actually using an English degree. Her heart belongs to the Denver Broncos and her husband. In that order.