Preliminary findings demonstrating latent effects of early adolescent marijuana use onset on cortical architecture.
BACKGROUND
As the most commonly used illicit substance during early adolescence, long-term or latent effects of early adolescent marijuana use across adolescent developmental processes remain to be determined.


METHODS
We examined cortical thickness, gray/white matter border contrast (GWR) and local gyrification index (LGI) in 42 marijuana (MJ) users. Voxelwise regressions assessed early-onset (age <16) vs. late-onset (≥16 years-old) differences and relationships to continued use while controlling for current age and alcohol use.


RESULTS
Although groups did not differ by onset status, groups diverged in their correlations between cannabis use and cortical architecture. Among early-onset users, continued years of MJ use and current MJ consumption were associated with thicker cortex, increased GWR and decreased LGI. Late-onset users exhibited the opposite pattern. This divergence was observed in all three morphological measures in the anterior dorsolateral frontal cortex (p<.05, FWE-corrected).


CONCLUSIONS
Divergent patterns between current MJ use and elements of cortical architecture were associated with early MJ use onset. Considering brain development in early adolescence, findings are consistent with disruptions in pruning. However, divergence with continued use for many years thereafter suggests altered trajectories of brain maturation during late adolescence and beyond.
Center for BrainHealth, School of Behavioral and Brain Sciences, The University of Texas at Dallas, United States. Electronic address: Francesca.Filbey@utdallas.edu.
Francesca M
FM
Filbey
Center for BrainHealth, School of Behavioral and Brain Sciences, The University of Texas at Dallas, United States.
Tim
T
McQueeny
Center for BrainHealth, School of Behavioral and Brain Sciences, The University of Texas at Dallas, United States.
Samuel J
SJ
DeWitt
Advance MRI, LLC, Frisco, TX, United States.
Virendra
V
Mishra
D000293:Adolescent; D017668:Age of Onset; D000375:Aging / Q000473:pathology; D000437:Alcoholism / Q000473:pathology; D001921:Brain / Q000254:growth & development / Q000473:pathology; D002540:Cerebral Cortex / Q000254:growth & development / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D066128:Gray Matter / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D002189:Marijuana Abuse / Q000473:pathology*; D066127:White Matter / Q000473:pathology
Adolescence; Cortical thickness; FreeSurfer; Gyrification; Marijuana; Morphology