title: Neurophysiological predictors of non-response to rTMS in depression.
abstract: BACKGROUND
  The application of rTMS in Depression has been very well investigated over the last few years. However, little is known about predictors of non-response associated with rTMS treatment.
  
  
  OBJECTIVE
  This study examined neurophysiological parameters (EEG and ERP) in 90 depressed patients treated with rTMS and psychotherapy and sought to identify predictors of non-response.
  
  
  METHODS
  This study is a multi-site open-label study assessing pre-treatment EEG and ERP measures associated with non-response to rTMS treatment.
  
  
  RESULTS
  Non-responders were characterized by 1) Increased fronto-central theta EEG power, 2) a slower anterior individual alpha peak frequency, 3) a larger P300 amplitude, and 4) decreased pre-frontal delta and beta cordance. A discriminant analysis yielded a significant model, and subsequent ROC curve demonstrated an area under the curve of 0.814.
  
  
  CONCLUSIONS
  Several EEG variables demonstrated clear differences between R and NR such as the anterior iAPF, fronto-central Theta and pre-frontal cordance in the Delta and Beta band (representative of increased relative pre-frontal perfusion). The increased P300 amplitude as a predictor for non-response requires further study, since this was the opposite as hypothesized and there were no correlations of this measure with clinical improvement for the whole sample. Combining these biomarkers in a discriminant analysis resulted in a reliable identification of non-responders with low false positive rates. Future studies should prospectively replicate these findings and also further investigate appropriate treatments for the sub-groups of non-responders identified in this study, given that most of these biomarkers have also been found in antidepressant medication studies.
authors.affiliation: Research Institute Brainclinics, Nijmegen, The Netherlands. martijn@brainclinics.com
authors.forename: Martijn
authors.initials: M
authors.lastname: Arns
authors.forename: Wilhelmus H
authors.initials: WH
authors.lastname: Drinkenburg
authors.forename: Paul B
authors.initials: PB
authors.lastname: Fitzgerald
authors.forename: J Leon
authors.initials: JL
authors.lastname: Kenemans
mesh_terms: D000328:Adult; D000368:Aged; D000513:Alpha Rhythm / Q000502:physiology; D001921:Brain / Q000503:physiopathology*; D003866:Depressive Disorder / Q000503:physiopathology / Q000628:therapy*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011795:Surveys and Questionnaires; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D017211:Treatment Failure