EEG in prediction of antidepressant response in patients with depressive disorder: review and extended pilot data
Abstract
Introduction: Previous studies of patients with unipolar depression have shown that early decreases of EEG cordance (a new quantitative EEG method) can predict clinical response. Cordance combines complementary informations from absolute and relative power of EEG spectra.
Recent studies have shown that cordance correlates with cortical perfusion. The authors discuss connection between cordance and activity of anterior cingulum.
The aim of study was to examine whether early QEEG decrease represents a phenomenon associated with response to treatment with different antidepressants in patients with treatment resistant depression. Method: The subjects were 24 inpatients with treatment resistant depression.
It is extended sample (17 inpatients) from our work, which was published previously. Clinical status and response to treatment were monitored at baseline and after 1 and 4 weeks on an antidepressant treatment.
QEEG cordance was computed at 3 frontal electrodes in theta frequency band in baseline and after week 1. Results: All 24 patients completed the 4-week study.
All six responders showed decreases in prefrontal cordance after the first week of treatment. Only 4 of the 18 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 in both groups) and the changes of prefrontal cordance values were different between both groups (p-value 0.001). Conclusion: Our results suggest that QEEG cordance may become a useful tool in the prediction of response to antidepressants.