title: Pretreatment measures of brain structure and reward-processing brain function in cannabis dependence: an exploratory study of relationships with abstinence during behavioral treatment.
abstract: BACKGROUND
  Cannabis is widely abused, and efficacies of therapeutics for cannabis dependence remain suboptimal. Magnetic resonance imaging (MRI) may aid in the identification of biological markers for successful treatment outcomes (i.e., abstinence).
  
  
  METHODS
  Twenty men with cannabis dependence and twenty non-substance-using healthy comparison (HC) men underwent MRI scanning. Cannabis-dependent individuals then participated in a 12-week randomized clinical trial of behavioral treatments (contingency management (CM), cognitive behavioral therapy (CBT) or both). Pretreatment functional and structural data were compared between the cannabis-dependent and HC participants. In addition, individuals with cannabis dependence were subdivided based on the successful achievement of 21 days of consecutive abstinence during treatment to assess whether abstinent versus non-abstinent cannabis-dependent participants displayed different pretreatment functional and structural characteristics when compared to HC participants.
  
  
  RESULTS
  In comparison to HC participants, cannabis-dependent participants demonstrated greater ventral striatal activation during the receipt of losing outcomes and smaller putamenal volumes. Cannabis-dependent participants who did not subsequently achieve 21 days of consecutive abstinence had increased activity within the striatum during the receipt of losing outcomes, relative to HC participants. Cannabis-dependent participants who did not achieve 21 days of abstinence had decreased bilateral putamen volumes prior to treatment, relative to HC participants.
  
  
  CONCLUSIONS
  Individual differences in pretreatment striatal function and structure may relate to individual differences in treatment responses for cannabis dependence. While mechanisms underlying these associations require further exploration, the striatum might mediate treatment responses via its role in associative reward-learning (e.g., through skills training in CBT or reinforcement of abstinence in CM).
authors.affiliation: Division of Substance Abuse, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Sarah W
authors.initials: SW
authors.lastname: Yip
authors.affiliation: Division of Substance Abuse, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Elise E
authors.initials: EE
authors.lastname: DeVito
authors.affiliation: Division of Substance Abuse, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Hedy
authors.initials: H
authors.lastname: Kober
authors.affiliation: Division of Substance Abuse, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Worhunsky
authors.affiliation: Division of Substance Abuse, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Carroll
authors.affiliation: Division of Substance Abuse, Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Department of Neurobiology, Yale University School of Medicine, New Haven, CT, USA; Yale Child Study Center, Yale University School of Medicine, New Haven, CT, USA. Electronic address: marc.potenza@yale.edu.
authors.forename: Marc N
authors.initials: MN
authors.lastname: Potenza
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology*; D015928:Cognitive Behavioral Therapy; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D002189:Marijuana Abuse / Q000473:pathology* / Q000523:psychology / Q000628:therapy*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012201:Reward; D013375:Substance Withdrawal Syndrome / Q000473:pathology / Q000523:psychology / Q000628:therapy; D055815:Young Adult
keywords: Cannabis dependence; Cognitive behavioral therapy; Contingency management; FSL-FIRST; Reward processing; fMRI