Male cannabis users had slower motor skills and shifted brain activation patterns, linked to higher cortisol levels
Among 60 participants, male cannabis users showed significantly slower psychomotor performance, shifted brain activation from visual to executive control regions, and higher cortisol levels compared to controls.
Quick Facts
What This Study Found
Thirty cannabis users (16 men, 14 women) and 30 matched controls were tested with neuropsychological assessments and fMRI during a finger-sequencing task.
Male, but not female, cannabis users had significantly slower psychomotor speed. As a group, cannabis users showed greater activation in a motor planning region (BA 6) but reduced activation in a primary visual area (BA 17) compared to controls.
This shift from visual processing regions to executive/attentional control areas suggested cannabis users relied on more effortful, less automated motor control. Cannabis users also had significantly higher salivary cortisol levels (p=0.002).
The authors proposed that elevated cortisol from chronic cannabis use may mediate the altered brain activation patterns and reduced motor efficiency.
Key Numbers
30 cannabis users vs 30 controls. Male users significantly slower on psychomotor tests. Greater BA 6 activation, reduced BA 17 activation in users. Salivary cortisol significantly higher (p=0.002) in cannabis users.
How They Did This
Cross-sectional study comparing 30 chronic active cannabis users (16M, 14F, ages 18-45) to 30 non-drug-using controls (16M, 14F, ages 19-44). fMRI during visually paced finger sequencing at 2 and 4 Hz. Salivary cortisol measured. Neuropsychological motor tests administered.
Why This Research Matters
The sex-specific finding (males affected, females not) and the cortisol elevation provided mechanistic insights into how chronic cannabis use may disrupt motor function through stress hormone pathways.
The Bigger Picture
The cortisol-mediated mechanism linked cannabis use to the stress response system, suggesting chronic use may alter hypothalamic-pituitary-adrenal (HPA) axis function in ways that affect brain efficiency.
What This Study Doesn't Tell Us
Cross-sectional design. Cannot determine whether cannabis caused the cortisol elevation or brain changes. Active cannabis users were tested, so acute intoxication effects cannot be fully separated from chronic effects.
Questions This Raises
- ?Why were male users more affected than females?
- ?Would cortisol levels and brain activation patterns normalize with abstinence?
Trust & Context
- Key Stat:
- Male cannabis users significantly slower; cortisol elevated (p=0.002)
- Evidence Grade:
- Well-matched cross-sectional fMRI study with sex-specific analysis but unable to establish causation.
- Study Age:
- Published in 2011. Research on sex differences in cannabis effects has expanded.
- Original Title:
- Altered brain activation during visuomotor integration in chronic active cannabis users: relationship to cortisol levels.
- Published In:
- The Journal of neuroscience : the official journal of the Society for Neuroscience, 31(49), 17923-31 (2011)
- Authors:
- King, George R, Ernst, Thomas, Deng, Weiran, Stenger, Andrew, Gonzales, Rachael M K, Nakama, Helenna, Chang, Linda
- Database ID:
- RTHC-00496
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Does cannabis make you slower?
In this study, male cannabis users showed significantly slower psychomotor performance, with their brains shifting to less efficient processing strategies. Female users were not significantly slower.
Does cannabis affect cortisol?
Cannabis users had significantly higher salivary cortisol (a stress hormone) than controls. The authors proposed this hormonal change could partly explain the altered brain activation patterns.
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Cite This Study
https://rethinkthc.com/research/RTHC-00496APA
King, George R; Ernst, Thomas; Deng, Weiran; Stenger, Andrew; Gonzales, Rachael M K; Nakama, Helenna; Chang, Linda. (2011). Altered brain activation during visuomotor integration in chronic active cannabis users: relationship to cortisol levels.. The Journal of neuroscience : the official journal of the Society for Neuroscience, 31(49), 17923-31. https://doi.org/10.1523/JNEUROSCI.4148-11.2011
MLA
King, George R, et al. "Altered brain activation during visuomotor integration in chronic active cannabis users: relationship to cortisol levels.." The Journal of neuroscience : the official journal of the Society for Neuroscience, 2011. https://doi.org/10.1523/JNEUROSCI.4148-11.2011
RethinkTHC
RethinkTHC Research Database. "Altered brain activation during visuomotor integration in ch..." RTHC-00496. Retrieved from https://rethinkthc.com/research/king-2011-altered-brain-activation-during
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.