[First off, after all of the tobacco/cigarette use medical problems for COPD, Lung Cancer, Emphyzema, &c., why is marijuana smoking ok? Secondly, except for the tax revenue, who in their right mind wants to push it? Alcohol is too ingrained in ALL (and Islam allows it if you go to sea!) human cultures to eliminate it. Why are we starting another addiction problem? This posting is an abstract of the full article in this month’s Journal of Neuroscience. You can go to their website and download the full thing if you want to.]
Cannabis Use Is Quantitatively Associated with Nucleus Accumbens and Amygdala Abnormalities in Young Adult Recreational Users
1. Jodi M. Gilman1,4,5,
2. John K. Kuster1,2,*,
3. Sang Lee1,6,*,
4. Myung Joo Lee1,6,*,
5. Byoung Woo Kim1,6,
6. Nikos Makris3,5,
7. Andre van der Kouwe4,5,
8. Anne J. Blood1,2,4,5,†, and
9. Hans C. Breiter1,2,4,6,†
1. Author contributions: J.M.G., M.J.L., B.K., N.M., A.J.v.d.K., A.B., and H.C.B. designed research; J.M.G., J.K.K., S.L., and A.J.v.d.K. performed research; M.J.L., B.K., A.B., and H.C.B. contributed unpublished reagents/analytic tools; J.M.G., J.K.K., S.L., M.J.L., N.M., A.B., and H.C.B. analyzed data; J.M.G., A.B., and H.C.B. wrote the paper.
2. ↵*J.K.K., S.L., and M.J.L. contributed equally to this work.
3. ↵†A.J.B. and H.C.B. contributed equally to this work.
1. The Journal of Neuroscience, 16 April 2014, 34(16): 5529-5538; doi: 10.1523/JNEUROSCI.4745-13.2014
• Full Text
• Full Text (PDF)
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.