PT  - JOURNAL ARTICLE
AU  - Orr, Catherine
AU  - Spechler, Philip
AU  - Cao, Zhipeng
AU  - Albaugh, Matthew
AU  - Chaarani, Bader
AU  - Mackey, Scott
AU  - D'Souza, Deepak
AU  - Allgaier, Nicholas
AU  - Banaschewski, Tobias
AU  - Bokde, Arun L.W.
AU  - Bromberg, Uli
AU  - Büchel, Christian
AU  - Burke Quinlan, Erin
AU  - Conrod, Patricia
AU  - Desrivières, Sylvane
AU  - Flor, Herta
AU  - Frouin, Vincent
AU  - Gowland, Penny
AU  - Heinz, Andreas
AU  - Ittermann, Bernd
AU  - Martinot, Jean-Luc
AU  - Martinot, Marie-Laure Paillère
AU  - Nees, Frauke
AU  - Papadopoulos Orfanos, Dimitri
AU  - Paus, Tomáš
AU  - Poustka, Luise
AU  - Millenet, Sabina
AU  - Fröhner, Juliane H.
AU  - Radhakrishnan, Rajiv
AU  - Smolka, Michael N.
AU  - Walter, Henrik
AU  - Whelan, Robert
AU  - Schumann, Gunter
AU  - Potter, Alexandra
AU  - Garavan, Hugh
TI  - Grey Matter Volume Differences Associated with Extremely Low Levels of Cannabis Use in Adolescence
AID  - 10.1523/JNEUROSCI.3375-17.2018
DP  - 2019 Mar 06
TA  - The Journal of Neuroscience
PG  - 1817--1827
VI  - 39
IP  - 10
4099  - http://www.jneurosci.org/content/39/10/1817.short
4100  - http://www.jneurosci.org/content/39/10/1817.full
SO  - J. Neurosci.2019 Mar 06; 39
AB  - Rates of cannabis use among adolescents are high, and are increasing concurrent with changes in the legal status of marijuana and societal attitudes regarding its use. Recreational cannabis use is understudied, especially in the adolescent period when neural maturation may make users particularly vulnerable to the effects of Δ-9-tetrahydrocannabinol (THC) on brain structure. In the current study, we used voxel-based morphometry to compare gray matter volume (GMV) in forty-six 14-year-old human adolescents (males and females) with just one or two instances of cannabis use and carefully matched THC-naive controls. We identified extensive regions in the bilateral medial temporal lobes as well as the bilateral posterior cingulate, lingual gyri, and cerebellum that showed greater GMV in the cannabis users. Analysis of longitudinal data confirmed that GMV differences were unlikely to precede cannabis use. GMV in the temporal regions was associated with contemporaneous performance on the Perceptual Reasoning Index and with future generalized anxiety symptoms in the cannabis users. The distribution of GMV effects mapped onto biomarkers of the endogenous cannabinoid system providing insight into possible mechanisms for these effects.SIGNIFICANCE STATEMENT Almost 35% of American 10th graders have reported using cannabis and existing research suggests that initiation of cannabis use in adolescence is associated with long-term neurocognitive effects. We understand very little about the earliest effects of cannabis use, however, because most research is conducted in adults with a heavy pattern of lifetime use. This study presents evidence suggesting structural brain and cognitive effects of just one or two instances of cannabis use in adolescence. Converging evidence suggests a role for the endocannabinoid system in these effects. This research is particularly timely as the legal status of cannabis is changing in many jurisdictions and the perceived risk by youth associated with smoking cannabis has declined in recent years.