title: Structural brain correlates of alcohol and cannabis use in recreational users.
abstract: BACKGROUND
  Previous studies on substance-dependent populations have shown that age of first use and duration of use are associated with alterations in regional brain volumes. However, it is not clear whether such alterations are factors that predispose young people to use, and so are also present in recreational users, or are a consequence of chronic exposure to substances and/or comorbid psychopathology.
  
  
  OBJECTIVE
  To investigate relationships between key brain structures and parameters of alcohol and cannabis use, in otherwise healthy male recreational users.
  
  
  METHODS
  High-resolution magnetic resonance imaging was used to measure hippocampal, amygdala, whole-brain and intracranial cavity (ICC) volumes in 22 young men with a history of both alcohol and cannabis use.
  
  
  RESULTS
  Linear regression analyses with hippocampal, amygdala and whole-brain volumes as the dependent variables and age and ICC as covariates were performed. Findings showed that use of cannabis and alcohol at an earlier age were independently predictive of larger amygdala volumes, whereas longer duration of cannabis use was predictive of smaller hippocampal volumes.
  
  
  CONCLUSIONS
  Our findings offer preliminary support for a relationship between patterns of substance use and regional brain volumes in recreational users. It is speculative, but possible that this relationship is an evidence of a neurobiological vulnerability to drug-taking behaviour.
authors.affiliation: 1Melbourne Neuropsychiatry Centre, Melbourne.
authors.forename: Murat
authors.initials: M
authors.lastname: Yücel
authors.affiliation: 2ORYGEN Research Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Melbourne, Australia.
authors.forename: Dan I
authors.initials: DI
authors.lastname: Lubman
authors.affiliation: 1Melbourne Neuropsychiatry Centre, Melbourne.
authors.forename: Dennis
authors.initials: D
authors.lastname: Velakoulis
authors.affiliation: 1Melbourne Neuropsychiatry Centre, Melbourne.
authors.forename: Michael T H
authors.initials: MT
authors.lastname: Wong
authors.affiliation: 1Melbourne Neuropsychiatry Centre, Melbourne.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Wood
authors.affiliation: 1Melbourne Neuropsychiatry Centre, Melbourne.
authors.forename: Anita
authors.initials: A
authors.lastname: Condello
authors.affiliation: 2ORYGEN Research Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Melbourne, Australia.
authors.forename: Warrick J
authors.initials: WJ
authors.lastname: Brewer
authors.affiliation: 1Melbourne Neuropsychiatry Centre, Melbourne.
authors.forename: Christos
authors.initials: C
authors.lastname: Pantelis