Does Cannabis Make you Forget Stuff?

Liz Filmer
22 Feb 2023

Cannabis is strongly associated with memory loss. Scientists agree that cannabis does influence memory to a certain degree; however, it's not clear how detrimental or permanent this effect can be.

Cannabis only seems to impact short-term memory whilst you are under the influence, so don't worry about losing memories of your childhood or anything.

Many drugs also impact short and long-term memory. For example, many sleep aids, antihistamines and even some antidepressants have effects on memory. But, of course, the biggest one is alcohol, notorious for causing blackouts and severe memory impairments following excessive use in later life.

All drugs or medicine have some side effects. It's worth remembering, however, that cannabis offers that people other benefits, such as increased creativity and spirituality, 

It's tough to say definitively how severe and long-lasting these memory effects are because there are so many variables. The dose, type of cannabis, frequency of use, tolerance, age, sex and other factors all change the outcome. You also have to add into the mix the use of alcohol, tobacco or caffeine, not to mention prescription medications. 

The main culprit for memory loss is thought to be THC. The cells in our body have cannabinoid receptors, and THC binds to some of these receptors called CB1 and CB2 receptors.

However, THC is only a partial agonist. This means it doesn't fully activate the receptor. The resulting partial activation creates the signature psychoactive effect of feeling stoned. So then, we have to consider CBD, which is less likely to bind to CB1 and CB2 receptors unless there is also THC.

If CBD and THC meet at a receptor in the brain, the CBD will kick the THC out, meaning that the effect of the THC will be less powerful. This means that if you use a strain of cannabis with more of a balance of THC and CBD, memory problems will likely be negated. Conversely, high-THC products like dabs, wax or vapes will worsen memory issues.

One prevailing theory about the effects of THC on memory involves a brain region called the hippocampus. This region is essential for learning and memory and contains CB1 and CB2 receptors.

It is thought that once THC binds to receptors in the hippocampus, it may trigger a release of more glutamate, a neurotransmitter essential for forming memories. More glutamate may sound good, but unfortunately, when the brain registers an excess of glutamate, it reacts by turning off the receptors glutamate needs to stick to form memories. THC may also affect other receptors involved in memory, such as acetylcholine and serotonin, in a similar way

More human studies are needed to understand the relationship between cannabis and memory fully. Much of the findings we currently rely on come from studies in animals, like rats and mice, so the results may not necessarily translate across to humans.

It isn't clear how long the supposed memory-dampening effects of cannabis linger. However, no good evidence suggests that it causes long-term or permanent damage to your memory.

If you're using cannabis and are worried that it is affecting your memory, there are some things that you can do.

Keep THC doses on the lower side and add CBD into the mix if possible. 
Do all the other positive things that are good for your memory, like eating healthily, exercising, and prioritising sleep. Like with many cognitive issues, it all lies within the context of how well you care for your brain overall.

Liz Filmer