Schizophrenia Patients Who Used Cannabis Had Better Emotional Memory and More Normal Brain Activity
Schizophrenia patients with a history of cannabis abuse showed better emotional memory and more preserved prefrontal brain function compared to non-using schizophrenia patients, though they still performed below healthy controls.
Quick Facts
What This Study Found
Researchers compared emotional memory and brain activation in three groups: 14 schizophrenia patients with cannabis abuse (dual-diagnosis, DD), 14 non-using schizophrenia patients (SCZ), and 21 healthy controls (HC). Non-using schizophrenia patients showed prominent impairment in recognizing both positive and negative emotional images, while cannabis-using patients showed smaller differences from healthy controls.
Brain imaging revealed that non-using patients activated different brain regions (temporal, parietal, limbic, occipital) while cannabis-using patients showed activation patterns more similar to controls, particularly preserving frontal and limbic region activity.
Key Numbers
14 DD patients, 14 SCZ patients, 21 healthy controls. Non-users showed prominent impairment for both positive and negative emotional recognition. Cannabis users showed smaller differences from controls. Cannabis users preserved frontal and limbic activation patterns.
How They Did This
Cross-sectional fMRI study comparing three groups during an emotional memory recognition task with positive and negative pictures. 14 dual-diagnosis patients, 14 non-using schizophrenia patients, 21 healthy controls.
Why This Research Matters
Emotional memory is critical for social functioning and quality of life. The finding that cannabis-using patients have relatively preserved emotional memory and prefrontal function may help explain why some patients use cannabis, potentially to maintain emotional and cognitive abilities that are otherwise impaired by their illness.
The Bigger Picture
This study adds to the growing evidence that cannabis-using schizophrenia patients may represent a cognitively less impaired subgroup. Their relatively preserved emotional memory could be a reason they seek cannabis, or it could reflect a different underlying neurobiology that both enables cannabis seeking and confers cognitive resilience.
What This Study Doesn't Tell Us
Small sample sizes (14 per patient group) limit generalizability. Cross-sectional design cannot determine whether better function preceded cannabis use or resulted from it. Cannabis abuse has other negative consequences (poor compliance, relapse) that this study did not address. The groups may differ on unmeasured variables.
Questions This Raises
- ?Does cannabis use actively preserve emotional memory in schizophrenia, or are patients with better function simply more likely to use cannabis?
- ?Would these patients do even better without cannabis?
- ?Does the preserved emotional function translate to better social outcomes?
Trust & Context
- Key Stat:
- Cannabis-using patients preserved frontal lobe function that non-users lost
- Evidence Grade:
- Small cross-sectional fMRI study; preliminary evidence that adds to the "cognitively less impaired" hypothesis.
- Study Age:
- Published in 2013. The relationship between cannabis use and cognitive function in schizophrenia continues to be investigated.
- Original Title:
- Cannabis abuse is associated with better emotional memory in schizophrenia: a functional magnetic resonance imaging study.
- Published In:
- Psychiatry research, 214(1), 24-32 (2013)
- Authors:
- Bourque, Josiane(2), Mendrek, Adrianna, Durand, Myriam, Lakis, Nadia, Lipp, Olivier, Stip, Emmanuel, Lalonde, Pierre, Grignon, Sylvain, Potvin, Stéphane
- Database ID:
- RTHC-00656
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Why would cannabis-using schizophrenia patients have better memory?
The leading explanation is not that cannabis improves memory, but that patients who develop schizophrenia with cannabis exposure may have started with better cognitive function. They may have needed the additional risk from cannabis to develop psychosis, whereas patients without cannabis exposure developed it from internal vulnerability alone, which is associated with greater cognitive impairment.
Should schizophrenia patients use cannabis to improve their cognition?
No. Despite the cognitive advantages found in cannabis-using patients, cannabis abuse in schizophrenia is associated with poor medication compliance, more frequent psychotic relapses, and worse overall outcomes. The cognitive differences likely reflect pre-existing differences between patient subgroups rather than a beneficial effect of cannabis.
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Cite This Study
https://rethinkthc.com/research/RTHC-00656APA
Bourque, Josiane; Mendrek, Adrianna; Durand, Myriam; Lakis, Nadia; Lipp, Olivier; Stip, Emmanuel; Lalonde, Pierre; Grignon, Sylvain; Potvin, Stéphane. (2013). Cannabis abuse is associated with better emotional memory in schizophrenia: a functional magnetic resonance imaging study.. Psychiatry research, 214(1), 24-32. https://doi.org/10.1016/j.pscychresns.2013.05.012
MLA
Bourque, Josiane, et al. "Cannabis abuse is associated with better emotional memory in schizophrenia: a functional magnetic resonance imaging study.." Psychiatry research, 2013. https://doi.org/10.1016/j.pscychresns.2013.05.012
RethinkTHC
RethinkTHC Research Database. "Cannabis abuse is associated with better emotional memory in..." RTHC-00656. Retrieved from https://rethinkthc.com/research/bourque-2013-cannabis-abuse-is-associated
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.