title: Cortical thickness in adolescent marijuana and alcohol users: A three-year prospective study from adolescence to young adulthood.
abstract: Studies suggest marijuana impacts gray and white matter neural tissue development, however few prospective studies have determined the relationship between cortical thickness and cannabis use spanning adolescence to young adulthood. This study aimed to understand how heavy marijuana use influences cortical thickness trajectories across adolescence. Subjects were adolescents with heavy marijuana use and concomitant alcohol use (MJ+ALC, n=30) and controls (CON, n=38) with limited substance use histories. Participants underwent magnetic resonance imaging and comprehensive substance use assessment at three independent time points. Repeated measures analysis of covariance was used to look at main effects of group, time, and Group × Time interactions on cortical thickness. MJ+ALC showed thicker cortical estimates across the brain (23 regions), particularly in frontal and parietal lobes (ps<.05). More cumulative marijuana use was associated with increased thickness estimates by 3-year follow-up (ps<.05). Heavy marijuana use during adolescence and into young adulthood may be associated with altered neural tissue development and interference with neuromaturation that can have neurobehavioral consequences. Continued follow-up of adolescent marijuana users will help understand ongoing neural changes that are associated with development of problematic use into adulthood, as well as potential for neural recovery with cessation of use.
authors.affiliation: Veterans Affairs San Diego Healthcare System, La Jolla, CA, USA; University of California San Diego, Department of Psychiatry, La Jolla, CA, USA.
authors.forename: Joanna
authors.initials: J
authors.lastname: Jacobus
authors.affiliation: Medical University of South Carolina, Department of Psychiatry and Behavioral Sciences, Charleston, SC, USA.
authors.forename: Lindsay M
authors.initials: LM
authors.lastname: Squeglia
authors.affiliation: University of California San Diego, Department of Psychiatry, La Jolla, CA, USA.
authors.forename: Alejandro D
authors.initials: AD
authors.lastname: Meruelo
authors.affiliation: University of California San Diego, Department of Psychiatry, La Jolla, CA, USA.
authors.forename: Norma
authors.initials: N
authors.lastname: Castro
authors.affiliation: University of California San Diego, Department of Psychiatry, La Jolla, CA, USA.
authors.forename: Ty
authors.initials: T
authors.lastname: Brumback
authors.affiliation: University of California San Diego, Department of Psychiatry, La Jolla, CA, USA.
authors.forename: Jay N
authors.initials: JN
authors.lastname: Giedd
authors.affiliation: Veterans Affairs San Diego Healthcare System, La Jolla, CA, USA; University of California San Diego, Department of Psychiatry, La Jolla, CA, USA. Electronic address: stapert@ucsd.edu.
authors.forename: Susan F
authors.initials: SF
authors.lastname: Tapert
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D000437:Alcoholism / Q000473:pathology*; D002540:Cerebral Cortex / Q000473:pathology*; D005260:Female; D005625:Frontal Lobe / Q000473:pathology; D006304:Health Status; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D002189:Marijuana Abuse / Q000473:pathology*; D008603:Mental Health; D010296:Parietal Lobe / Q000473:pathology; D011446:Prospective Studies; D020127:Recovery of Function; D012959:Socioeconomic Factors; D055815:Young Adult
keywords: Adolescence; Alcohol; Brain; Cortical thickness; Imaging; Marijuana