LITERATURE REVIEW:
The Effects of Cannabis on Memory
Joe Pizano
03/28/2025
Department of Social Sciences, UH-Downtown
PSY 3319: Cognitive Psychology
Professor Arthur Vallejo Jr., M.A.
Cannabis, its use to humanity goes back almost twelve thousand years ago and across numerous
ancient civilizations. [2] Despite this long history Cannabis, also known as Marijuana, is still illegal in
most of the western world and many parts of the rest of the world. Despite the status of ‘illegal’ in most
of the United States, in other parts of the world Cannabis is has been used for its medicinal qualities. In
some cultures, it is even believed to have a spiritual component.
Enter memory, something that is a vital component of human advancement and vital to the
function of society. There has always been the question of how we can improve current memory
capacity and how we can recover lost memories, additionally there are numerous degenerative diseases
that effect memory, such as dementia and Alzheimer’s. There are many components of memory,
episodic memory is a type of long-term memory that is under conscious control, specifically having to do
with ones own personal experiences. Semantic memory is the “just the facts” memories that are
subconsciously recalled. Recall is the process of retrieval of long-term memories.
There are many mixed feelings about the use of cannabis, in some places it is widely used and
accepted as an herb. In others it may be illegal, but still widely used. In some other places it is used to
make cloth or rope, known in this form as hemp. In the United States Cannabis is decriminalized in 31
states and Washington D.C., one of the arguments for legalization comes from the theory that Cannabis
contains a medicinal quality.
There have been numerous studies done on the effects of Marijuana/Cannabis and its possible
health benefits. However, the findings are not as black and white as “Good or Bad”. But rather finds that
conclude that cannabis does a few interesting things that could be beneficial under the right
circumstance while also inhibiting other processes.
In 2019 there was a study conducted on if cannabis use effects the Prospective Memory
of individuals. In the journal Joint effects of stress and chronic cannabis use on prospective memory.
Psychopharmacology [1]. Researchers studied the effects of acute and chronic stress combined with the
use of cannabis, frequent or non-frequent users. It is known that people use cannabis to unwind and
destress, but does it help cope with stress? In conclusion, it was found that acute stress detrimentally
effects prospective memory while these effects may be exacerbated by cannabis use.
In the journal Effect of Cannabis on Memory Consolidation, Learning and Retrieval and Its
Current Legal Status in India [2] the effects of cannabis were measured down to the chemical levels. The
two chemical components of cannabis are Tetrahydrocannabinol (THC) and cannabidiol (CBD). THC
being psychoactive. Based on the studies findings THC appears to be responsible for detrimental effects
on the cognitive domain whereas CBD attenuates the neurological disorders of deficits caused by THC. It
was noted that the negative effects or use are not outweighed by the possible benefits in a sense it
breaks even.
In the research article Effects of cannabis on eyewitness memory: A field study [3] memory was
the target of the study to find if cannabis helped or hurt one’s ability to recall. This study was a very
good practical application of the theory. The scenario is that eyewitnesses to a crime scene would be
tested on who remembered the most details of the crime. Based on the findings subjects under the
influence of cannabis remembered slightly fewer correct details about the event than sober witnesses.
However, when it came to identifying out of a line up, those intoxicated were slightly better at
decerning whether if their line up was accurate or not. This study was important because in recalling a
crime scene one must use episodic memory and consciously attempt to recall details that may or may
not be captured in the semantic memory mechanism. Given that memory functions by way of
reconstruction of small fragments into larger parts (Chunking). The findings conclude that use of
marijuana does, although slight, interfere with one’s ability to recall details of an eyewitness event.
In the investigating journal Effects of marijuana on visuospatial working memory:
an fMRI study in young adults [4] the effects of cannabis on visuospatial and working memory are
studied, as well as the effects on individuals of younger ages. Visuospatial working memory is the ability
to remember and manipulate spatial and visual information. Such as the visualizing of a 2D or 3D object
within the mental process. This is important for remembering locations, navigation and spatial
reasoning. In the experiment functional magnetic resonance imaging (fMRI) was used to see which
parts of the brain may be affected. It was found in the imaging that cannabis does affect neural
functioning during visuospatial working memory. This effect of cannabis is compensated for the
increased in blood flow to other parts of the brain. The deficits found by use of cannabis may not be
obviously observed unless under specific circumstances in the real-world application.
The journal entry Long-term effects of frequent cannabis use on working memory and attention:
an fMRI study [5] was focused on the effects of cannabis on conative abilities over a long period of time.
The objective of the study was to evaluate brain function in both frequent, yet moderate users, in
selective attention and working memory. In the result cannabis users and non-users preformed equal in
during memory and attention related tasks. It is unlikely that attention executive system is
compromised. However, this cannot be ruled out due to an abnormality in Left Superior Parietal Cortex,
this is the part of the brain involved in working memory. It is noted in the article that the earlier one
uses cannabis, the younger the user, the more severe the negative consequences on brain function at an
older age.
Across all journals the consensus is that the presence of cannabis does not give an advantage to
memory. Rather that it is more likely to impair brain function and inhibit working memory. There was
also no conclusive evidence that it helped with stress, while acute stress was found detrimental to
memory even with the presence of cannabis. There is still much research to be done that can find
conclusive evidence to if cannabis can help or inhibit memory function. As well as help us in the mastery
of cognitive psychology.
Citations:
1. Cuttler, C., Spradlin, A., Nusbaum, A. T., Whitney, P., Hinson, J. M., & McLaughlin, R. J. (2019).
Joint effects of stress and chronic cannabis use on prospective memory. Psychopharmacology,
236(6), 1973–1983. https://doi.org/10.1007/s00213-019-5184-9
2. Niloy, N., Hediyal, T. A., Vichitra, C., Sonali, S., Chidambaram, S. B., Gorantla, V. R., &
Mahalakshmi, A. M. (2023). Effect of Cannabis on Memory Consolidation, Learning and Retrieval
and Its Current Legal Status in India: A Review. Biomolecules, 13(1), 162.
https://doi.org/10.3390/biom13010162
3. Vredeveldt, A., Charman, S. D., den Blanken, A., & Hooydonk, M. (2018). Effects of cannabis on
eyewitness memory: A field study. Applied Cognitive Psychology, 32(4), 420–428.
https://doi.org/10.1002/acp.3414
4. Smith, A. M., Longo, C. A., Fried, P. A., Hogan, M. J., & Cameron, I. (2010). Effects of marijuana
on visuospatial working memory: an fMRI study in young adults. Psychopharmacology, 210(3),
429–438. https://doi.org/10.1007/s00213-010-1841-8
5. Jager, G., Kahn, R. S., Van Den Brink, W., Van Ree, J. M., & Ramsey, N. F. (2006). Long-term
effects of frequent cannabis use on working memory and attention: an fMRI study.
Psychopharmacology, 185(3), 358–368. https://doi.org/10.1007/s00213-005-0298-7