Systematic review finds cannabis users show altered brain activation during memory tasks
Cannabis users displayed altered brain functional activation during memory tasks, with verbal memory performance particularly affected.
Quick Facts
What This Study 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.
Key Numbers
12 fMRI studies identified showing altered functional brain activation in cannabis users during memory tasks.
How They Did This
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.
Why This Research 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 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.
What This Study Doesn't 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.
Questions This Raises
- ?How much cannabis exposure is needed to produce measurable memory-related brain changes?
- ?Do these changes fully reverse with sustained abstinence?
Trust & Context
- Key Stat:
- 12 fMRI studies showed altered brain activation in cannabis users during memory tasks
- Evidence Grade:
- Systematic review of neuroimaging studies, though the number of included studies was limited.
- Study Age:
- Published in 2020.
- Original Title:
- 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.
- Published In:
- Brain sciences, 10(2) (2020)
- Authors:
- Blest-Hopley, Grace(10), Giampietro, Vincent(14), Bhattacharyya, Sagnik(39)
- Database ID:
- RTHC-02429
Evidence Hierarchy
Analyzes all available research on a topic using a structured method.
What do these levels mean? →Frequently Asked Questions
Which type of memory was most affected by cannabis use?
Verbal memory showed the most consistent deficits across studies. The review noted that cannabis users performed worse particularly on tasks involving learning and recalling spoken or written information.
Can memory recover after stopping cannabis use?
The review found some evidence suggesting memory impairments may improve following cessation, but more research is needed to determine the full extent and timeline of recovery.
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Cite This Study
https://rethinkthc.com/research/RTHC-02429APA
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
MLA
Blest-Hopley, Grace, et al. "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, 2020. https://doi.org/10.3390/brainsci10020102
RethinkTHC
RethinkTHC Research Database. "A Systematic Review of Human Neuroimaging Evidence of Memory..." RTHC-02429. Retrieved from https://rethinkthc.com/research/blest-hopley-2020-a-systematic-review-of
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.