title: Changes in QEEG prefrontal cordance as a predictor of response to antidepressants in patients with treatment resistant depressive disorder: a pilot study.
abstract: BACKGROUND
  Previous studies of patients with unipolar depression have shown that early decreases of EEG cordance (a new quantitative EEG method) can predict clinical response. We examined whether early QEEG decrease represents a phenomenon associated with response to treatment with different antidepressants in patients with treatment resistant depression.
  
  
  METHODS
  The subjects were 17 inpatients with treatment resistant depression. EEG data and response to treatment were monitored at baseline and after 1 and 4 weeks on an antidepressant treatment. QEEG cordance was computed at three frontal electrodes in theta frequency band. The prefrontal cordance combines complementary information from absolute and relative power of EEG spectra. Recent studies have shown that cordance correlates with cortical perfusion. Depressive symptoms were assessed using Montgomery-Asberg Depression Rating Scale (MADRS).
  
  
  RESULTS
  All 17 patients completed the 4-week study. All five responders showed decreases in prefrontal cordance after the first week of treatment. Only 2 of the 12 nonresponders showed early prefrontal cordance decrease. The decrease of prefrontal QEEG cordance after week 1 in responders as well as the increase in nonresponders were both statistically significant (p-value 0.03 and 0.01, respectively) and the changes of prefrontal cordance values were different between both groups (p-value 0.001).
  
  
  CONCLUSIONS
  Our results suggest that decrease in prefrontal cordance may indicate early changes of prefrontal activity in responders to antidepressants. QEEG cordance may become a useful tool in the prediction of response to antidepressants.
authors.affiliation: Prague Psychiatric Centre, Ustavni 91, Prague 8 - Bohnice, 181 03, Czech Republic; 3rd Faculty of Medicine, Charles University, Ruska 87, Prague 10, 100 00, Czech Republic. bares@pcp.lf3.cuni.cz
authors.forename: Martin
authors.initials: M
authors.lastname: Bares
authors.forename: Martin
authors.initials: M
authors.lastname: Brunovsky
authors.forename: Miloslav
authors.initials: M
authors.lastname: Kopecek
authors.forename: Pavla
authors.initials: P
authors.lastname: Stopkova
authors.forename: Tomas
authors.initials: T
authors.lastname: Novak
authors.forename: Jiri
authors.initials: J
authors.lastname: Kozeny
authors.forename: Cyril
authors.initials: C
authors.lastname: Höschl
mesh_terms: D000328:Adult; D000465:Algorithms; D000928:Antidepressive Agents / Q000627:therapeutic use*; D003866:Depressive Disorder / Q000188:drug therapy* / Q000473:pathology*; D004351:Drug Resistance; D004569:Electroencephalography; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011237:Predictive Value of Tests; D017397:Prefrontal Cortex / Q000503:physiopathology*; D011569:Psychiatric Status Rating Scales; D012189:Retrospective Studies
chemical_list: D000928:Antidepressive Agents