“…A number of EEG studies have provided evidence that depressed patients (both those with current and past depressive episodes) display a frontal asymmetry characterized by greater left than right frontal lobe alpha power (hypoactivation) [34,42,43,51,137] and some authors have further demonstrated that posterior alpha power in depression exhibits an asymmetry opposite to that of frontal alpha, indicative of greater right than left posterior alpha power in depression [43,88,103,138]. However, not all studies have demonstrated this pattern of anterior lobe asymmetry being the reciprocal of posterior asymmetry in depression [65,139,140].…”