title: A voxel-based morphometry study of young occasional users of amphetamine-type stimulants and cocaine.
abstract: BACKGROUND
  Although the interaction of brain volume with amphetamine-type stimulants (ATS) and cocaine has been investigated in chronically dependent individuals, little is known about structural differences that might exist in individuals who consume ATS and cocaine occasionally but are not dependent on these drugs.
  
  
  METHODS
  Regional brain volumes in 165 college aged occasional users of ATS (namely: amphetamine, methamphetamine, methylphenidate, and 3,4-methylenedioxymethamphetamine; MDMA) and cocaine were compared by voxel-based morphometry with 48 ATS/cocaine-naive controls.
  
  
  RESULTS
  Grey matter volume was significantly higher in the left ventral anterior putamen of occasional users, and lower in the right dorsolateral cerebellum and right inferior parietal cortex. A regression in users alone on lifetime consumption of combined ATS (namely: amphetamine, methamphetamine, methylphenidate and MDMA) and cocaine use revealed that individuals who used more ATS/cocaine had greater volume in the right ventromedial frontal cortex. A second regression on lifetime consumption of ATS with cocaine as a covariate revealed that individuals with a greater history of ATS use alone had more grey matter volume in the left mid-insula. Interestingly, structural changes in the ventromedial prefrontal cortex, insula and striatum have been consistently observed in volumetric studies of chronic ATS and cocaine dependence.
  
  
  CONCLUSIONS
  The present results suggest that these three brain regions may play a role in stimulant use even in early occasional users.
authors.affiliation: Department of Psychiatry, University of California, San Diego, 8939 Villa La Jolla Drive suite 200, La Jolla, CA 92037, USA. Electronic address: msmackey@ucsd.edu.
authors.forename: Scott
authors.initials: S
authors.lastname: Mackey
authors.affiliation: Department of Psychiatry, University of California, San Diego, 8939 Villa La Jolla Drive suite 200, La Jolla, CA 92037, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Stewart
authors.affiliation: Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143, USA.
authors.forename: Colm G
authors.initials: CG
authors.lastname: Connolly
authors.affiliation: Department of Psychiatry, University of California, San Diego, 8939 Villa La Jolla Drive suite 200, La Jolla, CA 92037, USA.
authors.forename: Susan F
authors.initials: SF
authors.lastname: Tapert
authors.affiliation: Department of Psychiatry, University of California, San Diego, 8939 Villa La Jolla Drive suite 200, La Jolla, CA 92037, USA; Veterans Affairs San Diego Healthcare System, La Jolla, CA 92037, USA.
authors.forename: Martin P
authors.initials: MP
authors.lastname: Paulus
mesh_terms: D000367:Age Factors; D000662:Amphetamines / Q000008:administration & dosage*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism* / Q000473:pathology; D000697:Central Nervous System Stimulants / Q000008:administration & dosage; D003042:Cocaine / Q000008:administration & dosage*; D003430:Cross-Sectional Studies; D055030:Drug Users; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D055815:Young Adult
chemical_list: D000662:Amphetamines; D000697:Central Nervous System Stimulants; D003042:Cocaine
keywords: Amphetamine-type stimulants; Cocaine; Occasional; Structural neuroimaging; Voxel-based morphometry