Cannabis users displayed altered brain functional activation during memory tasks, with verbal memory performance particularly affected.
Researchers studying cannabis and cognition, people concerned about memory effects of cannabis use
12 fMRI studies showed altered brain activation in cannabis users during memory tasks
What the researchers found
Twelve fMRI studies showed cannabis users had altered brain activation during memory tasks compared to non-users. Performance studies indicated cannabis users performed worse on verbal memory tasks. Longitudinal studies suggested cannabis may play a causal role in memory deficits.
Why it matters
Understanding the neural basis of cannabis-related memory changes helps clarify whether observed deficits reflect altered brain processing rather than just behavioral differences.
The numbers in context
12 fMRI studies identified showing altered functional brain activation in cannabis users during memory tasks.
How the study worked
Systematic review of fMRI studies examining brain function during memory tasks in cannabis users vs. non-users, supplemented with narrative reviews of behavioral performance and preclinical evidence.
What this study cannot tell us
Limited number of fMRI studies available; heterogeneity in study designs, cannabis exposure measures, and memory tasks; preclinical evidence was not conclusive on memory deficits.
How to read the evidence
Systematic review of neuroimaging studies, though the number of included studies was limited.
When this study was published
Published in 2020.
The bigger picture
Memory impairments from cannabis may be linked to how heavily someone uses and when they started, with some evidence that deficits can improve after quitting.
Questions still open
- How much cannabis exposure is needed to produce measurable memory-related brain changes? Do these changes fully reverse with sustained abstinence?
Common questions
Which type of memory was most affected by cannabis use?
Can memory recover after stopping cannabis use?
Read the original research
A Systematic Review of Human Neuroimaging Evidence of Memory-Related Functional Alterations Associated with Cannabis Use Complemented with Preclinical and Human Evidence of Memory Performance Alterations.
Brain sciences, 10(2)
Citation
Blest-Hopley, Grace; Giampietro, Vincent; Bhattacharyya, Sagnik. (2020). A Systematic Review of Human Neuroimaging Evidence of Memory-Related Functional Alterations Associated with Cannabis Use Complemented with Preclinical and Human Evidence of Memory Performance Alterations.. Brain sciences, 10(2). https://doi.org/10.3390/brainsci10020102
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