title: Altered cerebral blood flow and neurocognitive correlates in adolescent cannabis users.
abstract: BACKGROUND
  The effects of adolescent marijuana use on the developing brain remain unclear, despite its prevalence. Arterial spin labeling (ASL) is a noninvasive imaging technique that characterizes neurovascular status and cerebral blood flow (CBF), potentially revealing contributors to neuropathological alterations. No studies to date have looked at CBF in adolescent marijuana users.
  
  
  OBJECTIVE
  This study examined CBF in adolescent marijuana users and matched healthy controls at baseline and after 4 weeks of monitored abstinence.
  
  
  METHODS
  Heavy adolescent marijuana users (n = 23, >200 lifetime marijuana use days) and demographically matched controls (n = 23) with limited substance exposure underwent an ASL brain scan at an initial session and after 4 weeks of sequential urine toxicology to confirm abstinence.
  
  
  RESULTS
  Marijuana users showed reduced CBF in four cortical regions including the left superior and middle temporal gyri, left insula, left and right medial frontal gyrus, and left supramarginal gyrus at baseline; users showed increased CBF in the right precuneus at baseline, as compared to controls (corrected p values < 0.05). No between group differences were found at follow-up.
  
  
  CONCLUSIONS
  Marijuana use may influence CBF in otherwise healthy adolescents acutely; however, group differences were not observed after several weeks of abstinence. Neurovascular alterations may contribute to or underlie changes in brain activation, neuropsychological performance, and mood observed in young cannabis users with less than a month of abstinence.
authors.affiliation: Psychology Service-116B, VA San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA 92161, USA.
authors.forename: Joanna
authors.initials: J
authors.lastname: Jacobus
authors.forename: Diane
authors.initials: D
authors.lastname: Goldenberg
authors.forename: Christina E
authors.initials: CE
authors.lastname: Wierenga
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Tolentino
authors.forename: Thomas T
authors.initials: TT
authors.lastname: Liu
authors.forename: Susan F
authors.initials: SF
authors.lastname: Tapert
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods / Q000523:psychology*; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000098:blood supply* / Q000187:drug effects; D002560:Cerebrovascular Circulation; D003071:Cognition / Q000502:physiology*; D004644:Emotions / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000523:psychology; D008297:Male; D002189:Marijuana Abuse / Q000503:physiopathology* / Q000523:psychology*; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012039:Regional Blood Flow; D013113:Spin Labels
chemical_list: D013113:Spin Labels