The influence of recency of use on fMRI response during spatial working memory in adolescent marijuana users. J Psychoactive Drugs 2010 Sep;42(3):401-12
Date
11/09/2010Pubmed ID
21053763Pubmed Central ID
PMC3016644DOI
10.1080/02791072.2010.10400703Scopus ID
2-s2.0-79551618878 (requires institutional sign-in at Scopus site) 78 CitationsAbstract
Some neurocognitive recovery occurs within a month of abstinence from heavy marijuana use, yet functional magnetic resonance imaging (fMRI) has revealed altered activation among recent and abstinent adult users. We compared fMRI response during a spatial working memory (SWM) task between adolescent marijuana users with brief and sustained durations of abstinence. Participants were 13 recent users (two to seven days abstinent), 13 abstinent users (27 to 60 days abstinent), and 18 nonusing controls, all ages 15 to 18. Groups were similar on demographics, had no psychiatric or medical disorders, and user groups were similar on substance histories. Teens performed a two-back SWM task during fMRI. Recent users showed greater fMRI response in medial and left superior prefrontal cortices, as well as bilateral insula. Abstinent users had increased response in the right precentral gyrus (clusters > or = 1328 microl, p < .05). Results suggest that adolescents who recently used marijuana show increased brain activity in regions associated with working memory updating and inhibition. This study preliminarily suggests that (1) recent marijuana use may disrupt neural connections associated with SWM and result in compensatory brain response, and (2) sustained abstinence from marijuana may be associated with improvements in SWM response among adolescents.
Author List
Schweinsburg AD, Schweinsburg BC, Medina KL, McQueeny T, Brown SA, Tapert SFAuthor
Krista Lisdahl PhD Assistant Professor in the Psychology department at University of Wisconsin - MilwaukeeMESH terms used to index this publication - Major topics in bold
AdolescentBrain
Brain Mapping
Female
Humans
Magnetic Resonance Imaging
Male
Marijuana Abuse
Memory, Short-Term
Time Factors
