title: Increase in PAS-induced neuroplasticity after a treatment course of transcranial direct current stimulation for depression.
abstract: BACKGROUND
  Several lines of evidence suggest that neuroplasticity is impaired in depression and improves with effective treatment. However until now, this evidence has largely involved measures such as learning and memory which can be influenced by subject effort and motivation. This pilot study aimed to objectively measure neuroplasticity in the motor cortex using paired associative stimulation (PAS), which induces short term neuroplastic changes. It is hypothesized that neuroplasticity would improve after effective treatment for depression.
  
  
  METHODS
  Neuroplasticity was measured in 18 depressed subjects before and after a course of anodal transcranial direct current stimulation (tDCS), given as treatment for depression. The relationships between PAS results, mood state and brain-derived neurotrophic factor (BDNF) serum levels were examined.
  
  
  RESULTS
  Neuroplasticity (PAS-induced change) was increased after a course of tDCS (t(17)=-2.651, p=0.017). Treatment with tDCS also led to significant mood improvement, but this did not correlate with improved neuroplasticity. Serum BDNF levels did not change after tDCS, or correlate with change in neuroplasticity after tDCS treatment.
  
  
  CONCLUSIONS
  While this study showed evidence of improved neuroplasticity in the motor cortex after effective treatment, we are unable to present evidence that this change is generalized in the depressed brain. Also, the presence of antidepressant medications and the small sample of patients (n=18) meant the study could not definitively resolve the relationship between neuroplasticity, mood and BDNF.
  
  
  CONCLUSIONS
  This novel preliminary study provides evidence that a treatment course of tDCS can improve neuroplasticity in depressed patients.
authors: School of Psychiatry, University of New South Wales, Sydney, Australia; Black Dog Institute, Hospital Road, Randwick, Sydney, NSW 2031, Australia.
authors: Michael J
authors: MJ
authors: Player
authors: Neuroscience Research Australia, Sydney, Australia; School of Medical Sciences, University of New South Wales, Sydney, Australia.
authors: Janet L
authors: JL
authors: Taylor
authors: School of Psychiatry, University of New South Wales, Sydney, Australia; Neuroscience Research Australia, Sydney, Australia; Schizophrenia Research Institute, Darlinghurst, Sydney, Australia.
authors: Cynthia Shannon
authors: CS
authors: Weickert
authors: School of Psychiatry, University of New South Wales, Sydney, Australia; Black Dog Institute, Hospital Road, Randwick, Sydney, NSW 2031, Australia.
authors: Angelo
authors: A
authors: Alonzo
authors: School of Psychiatry, University of New South Wales, Sydney, Australia; Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, Australia; Centre for Healthy Brain Ageing (CHeBA), University of New South Wales, Australia.
authors: Perminder S
authors: PS
authors: Sachdev
authors: School of Psychiatry, University of New South Wales, Sydney, Australia; Black Dog Institute, Hospital Road, Randwick, Sydney, NSW 2031, Australia.
authors: Donel
authors: D
authors: Martin
authors: School of Psychiatry, University of New South Wales, Sydney, Australia; Black Dog Institute, Hospital Road, Randwick, Sydney, NSW 2031, Australia.
authors: Philip B
authors: PB
authors: Mitchell
authors: School of Psychiatry, University of New South Wales, Sydney, Australia; Black Dog Institute, Hospital Road, Randwick, Sydney, NSW 2031, Australia; St. George Hospital, South Eastern Sydney Health, Australia. Electronic address: colleen.loo@unsw.edu.au.
authors: Colleen K
authors: CK
authors: Loo
mesh_terms: D000328:Adult; D000339:Affect; D000928:Antidepressive Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood; D003863:Depression / Q000628:therapy; D003865:Major Depressive Disorder / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology* / Q000628:therapy*; D005260:Female; D006801:Humans; D007858:Learning; D008297:Male; D008568:Memory; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009473:Neuronal Plasticity; D010865:Pilot Projects; D015203:Reproducibility of Results; D012107:Research Design; D065908:Transcranial Direct Current Stimulation; D016896:Treatment Outcome
chemical_list: D000928:Antidepressive Agents; D015415:Biomarkers; D019208:Brain-Derived Neurotrophic Factor
keywords: Major depressive disorder; Motor cortex; Neuroplasticity; Paired-associative stimulation; Transcranial direct current stimulation