Cannabis use is quantitatively associated with nucleus accumbens and amygdala abnormalities in young adult recreational users.
Jodi M Gilman, John K Kuster, Sang H. Lee, Myung Joo Lee, Byoung Woo Kim, Nikos Makris, Andre Van der Kouwe, Anne J Blood, Hans C Breiter
Journal of Neuroscience April 16, 2014 DOI: 10.1523/jneurosci.4745-13.2014 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cross-sectional study Peer reviewed |
|---|---|
| Population | Young adult recreational marijuana users and nonusing controls |
| Topics | Cannabis |
| Keywords | Gray matter density Multimodal imaging Reward Topology/shape |
| Key findings | Marijuana users showed greater gray matter density than controls in the left nucleus accumbens extending to subcallosal cortex, hypothalamus, sublenticular extended amygdala, and left amygdala, plus significant shape differences in the left nucleus accumbens and right amygdala. The authors suggest these exposure-dependent alterations in reward structures are consistent with animal studies of dendritic arborization changes. |
Abstract
Marijuana is the most commonly used illicit drug in the United States, but little is known about its effects on the human brain, particularly on reward/aversion regions implicated in addiction, such as the nucleus accumbens and amygdala. Animal studies show structural changes in brain regions such as the nucleus accumbens after exposure to Δ9-tetrahydrocannabinol, but less is known about cannabis use and brain morphometry in these regions in humans. We collected high-resolution MRI scans on young adult recreational marijuana users and nonusing controls and conducted three independent analyses of morphometry in these structures: (1) gray matter density using voxel-based morphometry, (2) volume (total brain and regional volumes), and (3) shape (surface morphometry). Gray matter density analyses revealed greater gray matter density in marijuana users than in control participants in the left nucleus accumbens extending to subcallosal cortex, hypothalamus, sublenticular extended amygdala, and left amygdala, even after controlling for age, sex, alcohol use, and cigarette smoking. Trend-level effects were observed for a volume increase in the left nucleus accumbens only. Significant shape differences were detected in the left nucleus accumbens and right amygdala. The left nucleus accumbens showed salient exposure-dependent alterations across all three measures and an altered multimodal relationship across measures in the marijuana group. These data suggest that marijuana exposure, even in young recreational users, is associated with exposure-dependent alterations of the neural matrix of core reward structures and is consistent with animal studies of changes in dendritic arborization.
Comparable studies
Other cross-sectional and survey studies on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Cannabis use before age 15 and subsequent executive functioning 104 chronic cannabis users (49 early-onset before age 15, 55 late-onset after age 15)... | 2011 | Observational cross-sectional study | n = 148 |
| Patterns of simultaneous polysubstance use in drug using university students Drug-using university students | 2006 | Cross-sectional survey | n = 149 |
| Persisting Reductions in Cannabis, Opioid, and Stimulant Misuse After Naturalistic Psychedelic Use: An Online Survey Online survey respondents | 2020 | Cross-sectional survey | |
| User perceptions of the benefits and harms of hallucinogenic drug use: A web-based questionnaire study Users of hallucinogenic drugs who completed a web-based questionnaire | 2010 | Cross-sectional survey | n = 600 |
| Illicit Use of LSD or Psilocybin, but not MDMA or Nonpsychedelic Drugs, is Associated with Mystical Experiences in a Dose-Dependent Manner Adults recruited from the MAPS website and newsletter, most reporting use of various... | 2012 | Cross-sectional survey | n = 337 |
Citations in the library
Cited by 26
- The neuropsychopharmacology of cannabis: A review of human imaging studies Pharmacology & Therapeutics October 20, 2018
- Grey Matter Volume Differences Associated with Extremely Low Levels of Cannabis Use in Adolescence Journal of Neuroscience January 14, 2019
- Verbal Memory Performance and Reduced Cortical Thickness of Brain Regions Along the Uncinate Fasciculus in Young Adult Cannabis Users Cannabis and Cannabinoid Research March 29, 2018
- Chronic adolescent exposure to cannabis in mice leads to sex-biased changes in gene expression networks across brain regions Neuropsychopharmacology August 22, 2022
- Three-day delta-9-tetrahydrocannabinol (THC) exposure eliminates long-term depression in ventral tegmental area of young, but not adult mice. Journal of Cannabis Research May 31, 2025
and 21 more in the library
Cites 6
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- Structural MRI findings in long-term cannabis users: what do we know? Substance Use & Misuse September 2010
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- Altered brain tissue composition in heavy marijuana users. Drug and Alcohol Dependence January 7, 2005
and 1 more in the library