There is evidence that EEG alpha may differentiate patients who clinically respond to pharmacological treatment from those who do not. Ulrich et al. (20) found increased posterior alpha in depressed patients who subsequently responded to amitriptyline. More recently, Bruder et al. (21) reported encouraging findings for predicting response to fluoxetine. Responders had greater alpha than nonresponders, with differences being topographically and functionally consistent with the classic alpha rhythm, i.e., evidence of reduced cortical activity in responders over posterior regions. They also found SSRI responders to differ from nonresponders in alpha symmetry, with responders showing relatively less cortical activity over right posterior regions. Neither alpha power nor asymmetry changed following treatment, which is consistent with alpha being a stable trait characteristic (22–24).
