Relevance: Marijuana is the most commonly used illicit drug in the U.S., and 6 percent of high school seniors report using marijuana >20 times per month. Neuromaturation continues during adolescence in the form of gray matter decreases and white matter increases, including in regions with dense distributions of cannabinoid receptors (e.g., frontal lobe, hippocampus, striatum, and cerebellum). However, few studies have examined the relationship between heavy marijuana use during adolescence and subsequent brain development. Longitudinal studies are essential to determine if previously observed abnormalities predate cannabis use or are caused by cannabinoid exposure. Description: In this application, we propose to recruit 78 adolescents to add to a cohort of 90 adolescents recruited in project R21 DA15228 (PI: Tapert), and follow these 168 teens with the same neuropsychological tests, functional magnetic resonance imaging (FMRI;working memory, inhibition, and learning tasks), MRI (to examine brain volume), and diffusion imaging (to probe white matter integrity) 1.5 and 3 years after the initial assessment. Brief interviews will be conducted each 6 months over the 3-year follow-up period to assess marijuana, alcohol, nicotine, and other drug use and academic involvement. Participants will be 126 heavy marijuana users and 42 non-users, recruited through two local school districts using the same approach as in R21 DA15228. At baseline, all participants will be age 16-18, free from psychiatric, learning, neurological, and medical disorders, and with limited exposure to alcohol, nicotine, and other drugs. Among users, late onset (after age 16) current users, early onset (less than or equal to 15) current users, and early onset (less than or equal to 15) former users will be targeted for recruitment. Prior to each imaging session, youths will undergo a 28-day monitored abstinence period by providing urine samples every 3-4 days and a hair sample for drug toxicology (as in R21 DA15228).
Aims :
Aims of the current application are to: (1) replicate preliminary findings of CNS differences between chronic heavy marijuana users and demographically similar non-users after 28 days of abstinence;(2) determine whether early onset (as opposed to duration) of heavy marijuana use is associated with abnormal CNS functioning;(3) determine if frequency and intensity of marijuana use predicts changes in brain imaging and cognitive test measures over a 3-year period;and (4) evaluate if FMRI response patterns during executive functioning tasks can predict subsequent substance use. All analyses will control for premorbid factors (i.e., family history of substance use disorders and personality), educational involvement (i.e., attendance), and other substance use (i.e., alcohol, nicotine, and other drugs).

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
5R01DA021182-05
Application #
7810744
Study Section
Child Psychopathology and Developmental Disabilities Study Section (CPDD)
Program Officer
Sirocco, Karen
Project Start
2006-05-10
Project End
2012-04-30
Budget Start
2010-05-01
Budget End
2012-04-30
Support Year
5
Fiscal Year
2010
Total Cost
$321,064
Indirect Cost
Name
Veterans Medical Research Fdn/San Diego
Department
Type
DUNS #
933863508
City
San Diego
State
CA
Country
United States
Zip Code
92161
Jacobus, Joanna; Castro, Norma; Squeglia, Lindsay M et al. (2016) Reprint of ""Adolescent cortical thickness pre- and post marijuana and alcohol initiation"". Neurotoxicol Teratol 58:78-87
Jacobus, Joanna; Castro, Norma; Squeglia, Lindsay M et al. (2016) Adolescent cortical thickness pre- and post marijuana and alcohol initiation. Neurotoxicol Teratol 57:20-29
Jacobus, Joanna; Squeglia, Lindsay M; Meruelo, Alejandro D et al. (2015) Cortical thickness in adolescent marijuana and alcohol users: A three-year prospective study from adolescence to young adulthood. Dev Cogn Neurosci 16:101-109
Jacobus, Joanna; Squeglia, Lindsay M; Infante, M Alejandra et al. (2015) Neuropsychological performance in adolescent marijuana users with co-occurring alcohol use: A three-year longitudinal study. Neuropsychology 29:829-43
Padula, Claudia B; McQueeny, Tim; Lisdahl, Krista M et al. (2015) Craving is associated with amygdala volumes in adolescent marijuana users during abstinence. Am J Drug Alcohol Abuse 41:127-32
Jacobus, Joanna; Tapert, Susan F (2014) Effects of cannabis on the adolescent brain. Curr Pharm Des 20:2186-93
Jacobus, Joanna; Squeglia, Lindsay M; Sorg, Scott F et al. (2014) Cortical thickness and neurocognition in adolescent marijuana and alcohol users following 28 days of monitored abstinence. J Stud Alcohol Drugs 75:729-43
Hanson, Karen L; Thayer, Rachel E; Tapert, Susan F (2014) Adolescent marijuana users have elevated risk-taking on the balloon analog risk task. J Psychopharmacol 28:1080-7
Winward, Jennifer L; Hanson, Karen L; Tapert, Susan F et al. (2014) Heavy alcohol use, marijuana use, and concomitant use by adolescents are associated with unique and shared cognitive decrements. J Int Neuropsychol Soc 20:784-95
Jacobus, Joanna; Squeglia, Lindsay M; Infante, M Alejandra et al. (2013) White matter integrity pre- and post marijuana and alcohol initiation in adolescence. Brain Sci 3:396-414

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