The present study was designed to confirm the predictive value of EEG alpha amplitude and asymmetry in a larger, independent sample of patients having a depressive disorder, and to extend the prior study in the following ways: First, we examined the predictive value not only for patients receiving an SSRI alone, but also those receiving dual treatment with an SSRI plus bupropion (i.e., an noradrenaline/dopamine reuptake inhibitor, NDRI) or an antidepressant with a dual mechanism of action (duloxetine or venlafaxine, both serontonin/noradrenaline reuptake inhibitors, SNRI). Second, to better identify and describe spectral topographic differences of interest, a dense recording montage (67-channels), and high-resolution EEG methods were used. Specifically, we used current source density (CSD) measures (25–26), which reduce volume conduction from distal sites, sharpen spatial resolution, and avoid problems associated with the recording reference (27–28). In contrast to rereferencing approaches to the ubiquitous reference problem for EEG recordings, CSD measures are unique (i.e, identical waveforms for any reference ), and are more closely related to neuronal activity, indicating the strength of underlying current generators as radial (transcranial) current flow (25–26,
