The change of QEEG prefrontal cordance as a response predictor to antidepressive intervention in bipolar depression. A pilot study.

OBJECTIVES

The aim of the study was to examine whether the change of quantitative EEG (QEEG) theta prefrontal cordance after one week of various antidepressive interventions predicts response to a 4-week treatment in patients with bipolar depression.

METHODS

We investigated 20 inpatients who completed a 4-week treatment. EEG data were monitored at baseline and after 1 week of treatment. QEEG cordance was computed at 3 frontal electrodes (Fp1, Fp2, Fz) in theta frequency band. Depressive symptoms and clinical status were assessed using Montgomery-Åsberg Depression Rating Scale (MADRS), Clinical Global Impression (CGI) and Young Mania Rating Scale (YMRS).

RESULTS

Seven of 8 responders (reduction of MADRS ≥50%) and only 2 of 12 non-responders had decreased prefrontal theta cordance value after the first week of treatment (p = 0.02). The positive and negative predictive values of cordance reduction for response were 0.78 and 0.91, respectively. We also found significant differences in cordance value reductions between responders and non-responders after week 1 and higher baseline cordance in responders.

CONCLUSION

The change in prefrontal theta cordance was associated with subsequent change in depressive symptoms and potentially might be a useful tool in the early detection of acute response to antidepressive interventions in bipolar depressed patients.