Quantitative EEG in the prediction of antidepressant response to imipramine

The purpose of this study was to examine the utility of quantitative electroencephalography (QEEG) in the prediction of response to imipramine in depressed patients. Forty patients with a diagnosis of unipolar depression were subjected to a placebo washout and were assessed at pre-drug, 3 h after their first dose of imipramine, and again 2 weeks into treatment. Following 4 weeks of open imipramine treatment, patients were separated into responder (R) and non-responder (NR) groups. Statistical analysis of the 29 patients who completed the study focused on group comparisons of power spectral estimates in four frequency bands from multi-channel recordings. Results showed that theta power differentiated R and NR groups prior to treatment, in response to an acute test dose, as well as after 2 weeks of active drug treatment. Results based on this exploratory study suggest that QEEG may be a useful early predictor of response to imipramine.