title: Neural mechanisms of sensitivity to peer information in young adult cannabis users.
abstract: Though social influence is a critical factor in the initiation and maintenance of marijuana use, the neural correlates of influence in those who use marijuana are unknown. In this study, marijuana-using young adults (MJ; n = 20) and controls (CON; n = 23) performed a decision-making task in which they made a perceptual choice after viewing the choices of unknown peers via photographs, while they underwent functional magnetic resonance imaging scans. The MJ and CON groups did not show differences in the overall number of choices that agreed with versus opposed group influence, but only the MJ group showed reaction time slowing when deciding against group choices. Longer reaction times were associated with greater activation of frontal regions. The MJ goup, compared to CON, showed significantly greater activation in the caudate when presented with peer information. Across groups, caudate activation was associated with self-reported susceptibility to influence. These findings indicate that young adults who use MJ may exhibit increased effort when confronted with opposing peer influence, as well as exhibit greater responsivity of the caudate to social information. These results not only better define the neural basis of social decisions, but also suggest that marijuana use is associated with exaggerated neural activity during decision making that involves social information.
authors.affiliation: Department of Psychiatry, Center for Addiction Medicine, Massachusetts General Hospital, Boston, MA, USA. jgilman1@partners.org.|Department of Radiology, Athinoula A. Martinos Center in Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA. jgilman1@partners.org.|Harvard Medical School, Boston, MA, USA. jgilman1@partners.org.
authors.forename: Jodi M
authors.initials: JM
authors.lastname: Gilman
authors.affiliation: Department of Psychiatry, Center for Addiction Medicine, Massachusetts General Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: Randi M
authors.initials: RM
authors.lastname: Schuster
authors.affiliation: Department of Psychiatry, Center for Addiction Medicine, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Max T
authors.initials: MT
authors.lastname: Curran
authors.affiliation: Department of Psychiatry, Center for Addiction Medicine, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Calderon
authors.affiliation: Department of Radiology, Athinoula A. Martinos Center in Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: Andre
authors.initials: A
authors.lastname: van der Kouwe
authors.affiliation: Department of Psychiatry, Center for Addiction Medicine, Massachusetts General Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: A Eden
authors.initials: AE
authors.lastname: Evins
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D016022:Case-Control Studies; D003657:Decision Making / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008385:Marijuana Smoking / Q000473:pathology* / Q000523:psychology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010379:Peer Group; D011930:Reaction Time / Q000502:physiology; D012919:Social Behavior; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Cannabis; Marijuana; Nucleus accumbens; Peer groups; Reward; Social influence