Cannabis Use And Memory Loss

Have you gotten stoned, tried to perform a task like cooking a meal or finishing some work, but kept forgetting what it was you were trying to do? 

Sound familiar? It’s commonly understood that smoking weed can impair your memory, but the evidence we have supporting this idea is largely anecdotal. Today, we’ll take a look at the science behind both memory and cannabis and learn more about how the two may be connected. Does weed affect memory, and if so, how? Keep reading to find out.

Cannabis and memory retention

Long-Term Memory Vs. Short-Term Memory

First, let’s start by going over how our brains encode memories and exploring the differences between short-term and long-term memory. 

Remembering an event, person, or piece of information begins with our perception. When we pay attention to something, we interpret the sensory stimuli associated with the noun we are perceiving. The smells, sounds, visuals of an experience converge in the thalamus, where our brains convert these individual bits of sensory information into one cohesive understanding—a memory.  

All of our experiences begin as short-term memories—fleeting amalgams of sensory input we store for less than a minute on average. The information we store as short-term memory is easily displaced by new sensory inputs and rapidly decays unless we commit the experience into our long-term memory.  

Why and how our brains convert ephemeral short-term memories into permanent long-term memories is still widely debated among the scientific community. Some theories suggest our brains automatically make this conversion given enough time with an experience, while others posit our brains only convert particular memories from short-term to long-term.  

Understanding The Effects Of Weed On The Brain

Effects of weed on the brain

The psychoactive compounds in cannabis, particularly THC, can significantly impact the way our brains operate. Here’s how it works: 

Our bodies are partially regulated by a complex cell signaling system known as the endocannabinoid system (ECS). By sending chemical messages throughout the brain and nervous system in the form of neurotransmitters called endocannabinoids, the endocannabinoid system helps maintain homeostasis. Essentially, it keeps us balanced. 

Functions such as mood, appetite, sleep patterns, and memory are all impacted by the endocannabinoid system.  

When we smoke marijuana or consume cannabis, the plant’s cannabinoids trigger the same neurotransmitter receptors the endocannabinoid system naturally activates with endocannabinoids. Different cannabinoids interact with the ECS in different ways, which explains the radical difference in the effects of compounds like THC and CBD.

Does Marijuana Cause Memory Loss? 

Can cannabis affect your memory?

Because the endocannabinoid system has direct involvement in our memory encoding processes, one would reasonably assume altering the system with cannabinoids would necessarily impact our memory.  

In the short-term, cannabis consumption can impact memory in two key ways. The first is by altering our perception. As we said before, the first step to creating a memory is perceiving the sensory inputs around you. While intoxicated on THC, perceptions often change. You may perceive time as slowing down or speeding up, or normally benign situations may suddenly seem perilous and anxiety-provoking. These shifts in perceptions not only change the way you experience the world in real-time, but also affect how you recall the events. 

Additionally, on a chemical level, cannabinoids’ interaction with the endocannabinoid system can disrupt or impair the process of encoding short-term memories. This accounts for the quintessential, “wait, what am I doing again?” moment almost all cannabis users have experienced at some point. 

Long-Term Effects Of Weed On Memory

So cannabis can disrupt your short-term memory, but what about in the long term? Does smoking weed have lasting effects on memory that extend past the period of intoxication? 

Unfortunately, we don’t have very much research into the long-term effects of chronic marijuana use, and the preliminary studies we do have are often conflicting. One study from 2011 conducted by the Scripps Research Institute titled “An Evidence Based Review of Acute and Long-Term Effects of Cannabis Use on Executive Cognitive Functions” found that while marijuana use can impair working memory during intoxication, after prolonged abstinence memory function returns to normal. However, other studies suggest that chronic use may lead to decreased cognitive function over time, especially if marijuana use begins in adolescence, though these implications remain unconfirmed.

Is Weed Bad For Your Brain? 

If getting high impairs short-term memory, does it mean it’s bad for your brain? Despite what the comically hyperbolic anti-marijuana PSAs of the ‘80s and ‘90s might have told you, cannabis use doesn’t kill brain cells. In fact, new research suggests it may actually have neuroprotective qualities that help prevent dementia and Alzheimer’s

Due to the complicated legal restrictions that surround cannabis, researchers have historically had difficulty studying the plant, its long-term effects, and its medicinal potential. Hopefully, we as a nation pass more cannabis-reform legislation, our scientific minds will be freer to unlock the mysteries locked inside the sticky buds of cannabis.