title: Brain perfusion in polysubstance users: relationship to substance and tobacco use, cognition, and self-regulation.
abstract: BACKGROUND
  Brain perfusion is altered in both alcohol dependence and stimulant dependence. Although most substance users also abuse/depend on alcohol concurrently (polysubstance users; PSU), rigorous perfusion research in PSU is limited. Also, the relationships of perfusion abnormalities with cognition, impulsivity, or decision making are not well known.
  
  
  METHODS
  Arterial spin labeling MRI and neuropsychological measures assessed perfusion levels and neurocognition in 20 alcohol-dependent individuals with comorbid-stimulant dependence (PSU), 26 individuals dependent on alcohol only (ALC), and 31 light/non-drinking controls (LD). The patient groups included smokers and non-smokers.
  
  
  RESULTS
  ALC had lower perfusion than LD in subcortical and cortical brain regions including the brain reward/executive oversight system (BREOS). Contrary to our hypothesis, regional perfusion was generally not lower in PSU than ALC. However, smoking PSU had lower perfusion than smoking ALC in several regions, including BREOS. Lower BREOS perfusion related to greater drinking severity in smoking substance users and to greater smoking severity in smoking ALC. Lower regional perfusion in ALC and PSU correlated with worse performance in different cognitive domains; smoking status affected perfusion-cognition relationships in ALC only. Lower BREOS perfusion in both substance using groups related to higher impulsivity.
  
  
  CONCLUSIONS
  Although regional perfusion was not decreased in PSU as a group, the combination of cigarette smoking and polysubstance use is strongly related to hypoperfusion in important cortical and subcortical regions. As lower perfusion relates to greater smoking severity, worse cognition and higher impulsivity, smoking cessation is warranted for treatment-seeking PSU and ALC.
authors.affiliation: Center for Imaging of Neurodegenerative Diseases (CIND), San Francisco VA Medical Center, San Francisco, CA, USA; Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA. Electronic address: donna.murray@ucsf.edu.
authors.forename: Donna E
authors.initials: DE
authors.lastname: Murray
authors.affiliation: Center for Imaging of Neurodegenerative Diseases (CIND), San Francisco VA Medical Center, San Francisco, CA, USA; Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Durazzo
authors.affiliation: School of Applied Sciences and Statistics, Koforidua Polytechnic, Ghana.
authors.forename: Anderson
authors.initials: A
authors.lastname: Mon
authors.affiliation: Center for Imaging of Neurodegenerative Diseases (CIND), San Francisco VA Medical Center, San Francisco, CA, USA; Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Schmidt
authors.affiliation: Center for Imaging of Neurodegenerative Diseases (CIND), San Francisco VA Medical Center, San Francisco, CA, USA; Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.
authors.forename: Dieter J
authors.initials: DJ
authors.lastname: Meyerhoff
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000503:physiopathology / Q000523:psychology; D001921:Brain / Q000503:physiopathology*; D003071:Cognition / Q000502:physiology*; D055030:Drug Users / Q000523:psychology; D005260:Female; D006801:Humans; D007175:Impulsive Behavior / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012201:Reward; D012907:Smoking / Q000503:physiopathology* / Q000523:psychology; D012927:Social Control, Informal; D019966:Substance-Related Disorders / Q000503:physiopathology* / Q000523:psychology
keywords: Alcohol; Blood flow; MRI; Perfusion; Polysubstance; Smoking