26. 9. 2009 - 29. 9. 2009
Prediction, particularly prediction of the therapeutic outcome is one of the big challenges in medicine including psychiatry (1). Due to long-lasting onset of action of antidepressants (1-3 weeks), early prediction of a therapeutic outcome could save time, money and unnecessary suffering. Previous studies of patients with unipolar depression have shown that early decreases of EEG cordance (a new quantitative EEG method) can predict clinical response (2;3). We examined whether this early QEEG decrease represents a phenomenon associated with response to treatment with different antidepressants in patients with treatment resistant depression.
The subjects were 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 might correlate with cortical perfusion reflecting to some extent regional activity of anterior cingulate. Depressive symptoms were assessed using Montgomery–Asberg Depression Rating Scale (MADRS).
Almost all responders showed decreases in prefrontal cordance after the first week of treatment. Only few of the non-responders showed early prefrontal cordance decrease. The decreases of prefrontal QEEG cordance after week 1 in responders as well as the increases in non-responders were both statistically significant and the changes of prefrontal cordance values were different between both groups.
Our results suggest that decrease in prefrontal cordance may indicate early changes of prefrontal activity in responders to antidepressants. QEEG cordance thus may become a useful tool in the early prediction of response to antidepressants.
(1) Höschl C. Prediction: Nonsense or Hope? Br J Psychiat, 163(S21);1993:46-54
(2) Bareš M, Brunovský M, Kopeček M, Stopková P, Novák T, Kožený J, Höschl C. Changes in QEEG prefrontal cordance as a predictor of response to antidepressants in patients with treatment resistant depressive disorder: A pilot study. J Psych Res, 41;2007, 3-4: 319-325
(3) Bares M, Brunovsky M, Kopecek M, Novak T, Stopkova P, Kozeny J, Sos P, Krajca V, Höschl C. Early reduction in prefrontal theta QEEG cordance value predicts response to venlafaxine treatment in patients with resistant depressive disorder. Eur Psychiatry. 2008; 23, 5:350-355