title: Exploratory study of once-daily transcranial direct current stimulation (tDCS) as a treatment for auditory hallucinations in schizophrenia.
abstract: BACKGROUND
  Auditory hallucinations are resistant to pharmacotherapy in about 25% of adults with schizophrenia. Treatment with noninvasive brain stimulation would provide a welcomed additional tool for the clinical management of auditory hallucinations. A recent study found a significant reduction in auditory hallucinations in people with schizophrenia after five days of twice-daily transcranial direct current stimulation (tDCS) that simultaneously targeted left dorsolateral prefrontal cortex and left temporo-parietal cortex.
  
  
  OBJECTIVE
  We hypothesized that once-daily tDCS with stimulation electrodes over left frontal and temporo-parietal areas reduces auditory hallucinations in patients with schizophrenia.
  
  
  METHODS
  We performed a randomized, double-blind, sham-controlled study that evaluated five days of daily tDCS of the same cortical targets in 26 outpatients with schizophrenia and schizoaffective disorder with auditory hallucinations.
  
  
  RESULTS
  We found a significant reduction in auditory hallucinations measured by the Auditory Hallucination Rating Scale (F2,50=12.22, P<0.0001) that was not specific to the treatment group (F2,48=0.43, P=0.65). No significant change of overall schizophrenia symptom severity measured by the Positive and Negative Syndrome Scale was observed.
  
  
  CONCLUSIONS
  The lack of efficacy of tDCS for treatment of auditory hallucinations and the pronounced response in the sham-treated group in this study contrasts with the previous finding and demonstrates the need for further optimization and evaluation of noninvasive brain stimulation strategies. In particular, higher cumulative doses and higher treatment frequencies of tDCS together with strategies to reduce placebo responses should be investigated. Additionally, consideration of more targeted stimulation to engage specific deficits in temporal organization of brain activity in patients with auditory hallucinations may be warranted.
authors: Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Electronic address: flavio_frohlich@med.unc.edu.
authors: F
authors: F
authors: Fröhlich
authors: Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors: T N
authors: TN
authors: Burrello
authors: Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors: J M
authors: JM
authors: Mellin
authors: Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors: A L
authors: AL
authors: Cordle
authors: Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors: C M
authors: CM
authors: Lustenberger
authors: Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors: J H
authors: JH
authors: Gilmore
authors: Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors: L F
authors: LF
authors: Jarskog
mesh_terms: D000328:Adult; D001303:Auditory Cortex / Q000473:pathology; D004311:Double-Blind Method; D005260:Female; D005625:Frontal Lobe / Q000473:pathology; D006212:Hallucinations / Q000175:diagnosis / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010296:Parietal Lobe / Q000473:pathology; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis / Q000523:psychology / Q000628:therapy; D012559:Schizophrenia / Q000175:diagnosis / Q000628:therapy; D012565:Schizophrenic Psychology; D065908:Transcranial Direct Current Stimulation / Q000379:methods*; D016896:Treatment Outcome
keywords: AHRS; Auditory hallucinations; Brain stimulation; PANSS; Placebo response; tDCS