title: Effects of transcranial direct current stimulation on craving, heart-rate variability and prefrontal hemodynamics during smoking cue exposure.
abstract: Drug-related cue exposure elicits craving and risk for relapse during recovery. Transcranial direct current stimulation is a promising research tool and possible treatment for relapse prevention. Enhanced functional neuroconnectivity is discussed as a treatment target. The goal of this research was to examine whether transcranial direct current stimulation affected cortical hemodynamic indicators of functional connectivity, craving, and heart rate variability during smoking-related cue exposure in non-treatment-seeking smokers.
  
  
  
  In vivo smoking cue exposure supported by a 2mA transcranial direct current stimulation (anode: dorsolateral prefrontal cortex, cathode: orbitofrontal cortex; placebo-controlled, randomized, double-blind) in 29 (age: M=25, SD=5) German university students (smoking at least once a week). Cue reactivity was assessed on an autonomous (heart rate variability) and a subjective level (craving ratings). Functional near-infrared spectroscopy measured changes in the concentration of deoxygenated hemoglobin, and seed-based correlation analysis was used to quantify prefrontal connectivity of brain regions involved in cue reactivity.
  
  
  
  Cue exposure elicited increased subjective craving and heart rate variability changes in smokers. Connectivity between the orbitofrontal and dorsolateral prefrontal cortex was increased in subjects receiving verum compared to placebo stimulation (d=0.66). Hemodynamics in the left dorsolateral prefrontal cortex, however, increased in the group receiving sham stimulation (η2=0.140). Transcranial direct current stimulation did not significantly alter craving or heart rate variability during cue exposure.
  
  
  
  Prefrontal connectivity - between regions involved in the processing of reinforcement value and cognitive control - was increased by anodal transcranial direct current stimulation during smoking cue exposure. Possible clinical implications should be considered in future studies.
authors.affiliation: Department of Psychiatry and Psychotherapy Tuebingen, University of Tuebingen, Germany; Graduate School of Neural and Behavioural Sciences Tuebingen, Germany. Electronic address: Agnes.Kroczek@med.uni-tuebingen.de.
authors.forename: A M
authors.initials: AM
authors.lastname: Kroczek
authors.affiliation: Department of Psychiatry and Psychotherapy Tuebingen, University of Tuebingen, Germany; Graduate School of Neural and Behavioural Sciences Tuebingen, Germany.
authors.forename: F B
authors.initials: FB
authors.lastname: Häußinger
authors.affiliation: Department of Psychiatry and Psychotherapy Tuebingen, University of Tuebingen, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Rohe
authors.affiliation: Department of Psychiatry and Psychotherapy Tuebingen, University of Tuebingen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Schneider
authors.affiliation: Department of Psychiatry and Psychotherapy Tuebingen, University of Tuebingen, Germany; Werner Reichardt Centre for Integrative Neuroscience, Tuebingen, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Plewnia
authors.affiliation: Department of Psychiatry and Psychotherapy Tuebingen, University of Tuebingen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Batra
authors.affiliation: Department of Psychiatry and Psychotherapy Tuebingen, University of Tuebingen, Germany; LEAD Graduate School Tuebingen, Germany; Werner Reichardt Centre for Integrative Neuroscience, Tuebingen, Germany.
authors.forename: A J
authors.initials: AJ
authors.lastname: Fallgatter
authors.affiliation: Department of Psychiatry and Psychotherapy Tuebingen, University of Tuebingen, Germany; LEAD Graduate School Tuebingen, Germany.
authors.forename: A-C
authors.initials: AC
authors.lastname: Ehlis
mesh_terms: D000328:Adult; D066249:Craving / Q000502:physiology*; D003463:Cues; D004311:Double-Blind Method; D005260:Female; D059907:Functional Neuroimaging; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D017397:Prefrontal Cortex / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000503:physiopathology; D012907:Smoking / Q000503:physiopathology*; D019265:Spectroscopy, Near-Infrared; D065908:Transcranial Direct Current Stimulation; D055815:Young Adult
keywords: Craving; Cue exposure; Cue reactivity; Heart rate variability; Smokers; fNIRS; tDCS