title: Does incentive-elicited nucleus accumbens activation differ by substance of abuse? An examination with adolescents.
abstract: Numerous questions surround the nature of reward processing in the developing adolescent brain, particularly in regard to polysubstance use. We therefore sought to examine incentive-elicited brain activation in the context of three common substances of abuse (cannabis, tobacco, and alcohol). Due to the role of the nucleus accumbens (NAcc) in incentive processing, we compared activation in this region during anticipation of reward and loss using a monetary incentive delay (MID) task. Adolescents (ages 14-18; 66% male) were matched on age, gender, and frequency of use of any common substances within six distinct groups: cannabis-only (n=14), tobacco-only (n=34), alcohol-only (n=12), cannabis+tobacco (n=17), cannabis+tobacco+alcohol (n=17), and non-using controls (n=38). All groups showed comparable behavioral performance on the MID task. The tobacco-only group showed decreased bilateral nucleus accumbens (NAcc) activation during reward anticipation as compared to the alcohol-only group, the control group, and both polysubstance groups. Interestingly, no differences emerged between the cannabis-only group and any of the other groups. Results from this study suggest that youth who tend toward single-substance tobacco use may possess behavioral and/or neurobiological characteristics that differentiate them from both their substance-using and non-substance-using peers.
authors.affiliation: University of Colorado, Boulder, Department of Psychology and Neuroscience, 345 UCB, Boulder, CO 80309, USA. Electronic address: hollis.karoly@colorado.edu.
authors.forename: Hollis C
authors.initials: HC
authors.lastname: Karoly
authors.affiliation: University of Colorado, Boulder, Department of Psychology and Neuroscience, 345 UCB, Boulder, CO 80309, USA.
authors.forename: Angela D
authors.initials: AD
authors.lastname: Bryan
authors.affiliation: University of Colorado, Boulder, Department of Psychology and Neuroscience, 345 UCB, Boulder, CO 80309, USA.
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Weiland
authors.affiliation: The Mind Research Network/LBERI, Albuquerque, NM 87106, USA; Neurology Department, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA; Department of Psychology, University of New Mexico, Albuquerque, NM 87131, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Mayer
authors.affiliation: The Mind Research Network/LBERI, Albuquerque, NM 87106, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Dodd
authors.affiliation: Department of Psychiatry, Oregon Health & Science University, Portland, OR 97239, USA.
authors.forename: Sarah W
authors.initials: SW
authors.lastname: Feldstein Ewing
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000187:drug effects*; D000437:Alcoholism / Q000503:physiopathology / Q000523:psychology; D059031:Anticipation, Psychological / Q000187:drug effects; D065786:Delay Discounting / Q000187:drug effects; D004347:Drug Interactions; D005106:Exploratory Behavior; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D002189:Marijuana Abuse / Q000503:physiopathology / Q000523:psychology; D009714:Nucleus Accumbens / Q000187:drug effects / Q000503:physiopathology*; D012201:Reward; D012959:Socioeconomic Factors; D019966:Substance-Related Disorders / Q000503:physiopathology* / Q000523:psychology*; D064424:Tobacco Use / Q000503:physiopathology / Q000523:psychology
keywords: Adolescent; Cannabis; Monetary incentive delay; Tobacco; fMRI