title: Striatum and insula dysfunction during reinforcement learning differentiates abstinent and relapsed methamphetamine-dependent individuals.
abstract: OBJECTIVE
  Individuals with methamphetamine dependence (MD) exhibit dysfunction in brain regions involved in goal maintenance and reward processing when compared with healthy individuals. We examined whether these characteristics also reflect relapse vulnerability within a sample of MD patients.
  
  
  METHODS
  Longitudinal, with functional magnetic resonance imaging (fMRI) and clinical interview data collected at baseline and relapse status collected at 1-year follow-up interview.
  
  
  METHODS
  Keck Imaging Center, University of California San Diego, USA.
  
  
  METHODS
  MD patients (n = 60) enrolled into an in-patient drug treatment program at baseline. MD participants remaining abstinent at 1-year follow-up (abstinent MD group; n = 42) were compared with MD participants who relapsed within this period (relapsed MD group; n = 18).
  
  
  METHODS
  Behavioral and neural responses to a reinforcement learning (paper-scissors-rock) paradigm recorded during an fMRI session at time of treatment.
  
  
  RESULTS
  The relapsed MD group exhibited greater bilateral inferior frontal gyrus (IFG) and right striatal activation than the abstinent MD group during the learning of reward contingencies (Cohen's d range: 0.60-0.83). In contrast, the relapsed MD group displayed lower bilateral striatum, bilateral insula, left IFG and left anterior cingulate activation than the abstinent MD group (Cohen's d range: 0.90-1.23) in response to winning, tying and losing feedback.
  
  
  CONCLUSIONS
  Methamphetamine-dependent individuals who achieve abstinence and then relapse show greater inferior frontal gyrus activation during learning, and relatively attenuated striatal, insular and frontal activation in response to feedback, compared with methamphetamine-dependent people who remain abstinent.
authors: Department of Psychiatry, University of California San Diego, La Jolla, CA, USA.
authors: Jennifer L
authors: JL
authors: Stewart
authors: Colm G
authors: CG
authors: Connolly
authors: April C
authors: AC
authors: May
authors: Susan F
authors: SF
authors: Tapert
authors: Marc
authors: M
authors: Wittmann
authors: Martin P
authors: MP
authors: Paulus
mesh_terms: D000328:Adult; D019969:Amphetamine-Related Disorders / Q000503:physiopathology*; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000503:physiopathology; D003657:Decision Making / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D059907:Functional Neuroimaging; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D007858:Learning / Q000502:physiology*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008694:Methamphetamine; D008875:Middle Aged; D017072:Neostriatum / Q000503:physiopathology*; D017397:Prefrontal Cortex / Q000503:physiopathology*; D012008:Recurrence; D012054:Reinforcement, Psychology; D012201:Reward; D055815:Young Adult
chemical_list: D008694:Methamphetamine
keywords: Decision-making; fMRI; learning; methamphetamine; relapse; reward