title: A preliminary investigation of Stroop-related intrinsic connectivity in cocaine dependence: associations with treatment outcomes.
abstract: BACKGROUND
  Cocaine-dependent individuals demonstrate neural and behavioral differences compared to healthy comparison subjects when performing the Stroop color-word interference test. Stroop measures also relate to treatment outcome for cocaine dependence. Intrinsic connectivity analyses assess the extent to which task-related regional brain activations are related to each other in the absence of defining a priori regions of interest.
  
  
  OBJECTIVE
  This study examined 1) the extent to which cocaine-dependent and non-addicted individuals differed on measures of intrinsic connectivity during fMRI Stroop performance; and 2) the relationships between fMRI Stroop intrinsic connectivity and treatment outcome in cocaine dependence.
  
  
  METHODS
  Sixteen treatment-seeking cocaine-dependent patients and matched non-addicted comparison subjects completed an fMRI Stroop task. Between-group differences in intrinsic connectivity were assessed and related to self-reported and urine-toxicology-based cocaine-abstinence measures.
  
  
  RESULTS
  Cocaine-dependent patients vs. comparison subjects showed less intrinsic connectivity in cortical and subcortical regions. When adjusting for individual degree of intrinsic connectivity, cocaine-dependent vs. comparison subjects showed relatively greater intrinsic connectivity in the ventral striatum, putamen, inferior frontal gyrus, anterior insula, thalamus and substantia nigra. Non-mean-adjusted intrinsic-connectivity measures in the midbrain, thalamus, ventral striatum, substantia nigra, insula and hippocampus negatively correlated with measures of cocaine abstinence.
  
  
  CONCLUSIONS
  The diminished intrinsic connectivity in cocaine-dependent vs. comparison subjects suggests poorer communication across brain regions during cognitive-control processes. In mean-adjusted analyses, the cocaine-dependent group displayed relatively greater Stroop-related connectivity in regions implicated in motivational processes in addictions. The relationships between treatment outcomes and connectivity in the midbrain and basal ganglia suggest that connectivity represents a potential treatment target.
authors.affiliation: Department of Psychiatry, Yale University School of Medicine , New Haven , Connecticut .
authors.forename: Marci R
authors.initials: MR
authors.lastname: Mitchell
authors.forename: Iris M
authors.initials: IM
authors.lastname: Balodis
authors.forename: Elise E
authors.initials: EE
authors.lastname: Devito
authors.forename: Cheryl M
authors.initials: CM
authors.lastname: Lacadie
authors.forename: Jon
authors.initials: J
authors.lastname: Yeston
authors.forename: Dustin
authors.initials: D
authors.lastname: Scheinost
authors.forename: R Todd
authors.initials: RT
authors.lastname: Constable
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Carroll
authors.forename: Marc N
authors.initials: MN
authors.lastname: Potenza
mesh_terms: D000328:Adult; D001921:Brain / Q000378:metabolism*; D016022:Case-Control Studies; D019970:Cocaine-Related Disorders / Q000503:physiopathology*; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009042:Motivation; D057190:Stroop Test; D016896:Treatment Outcome