The topographical features of EEGs in patients with affective disorders

EEG data were obtained in the basic state from 16 scalp sites of 44 patients with affective disorder, diagnosed by DSM-III criteria, and 44 normal controls. The EEG power spectra were computed and the t statistic significance probability mapping (SPM) was applied to visualize regions where the patient group showed differences in the EEG topogram from the controls. The results show: (1) left occipital predominance (P3, O1) of alpha activities in the patients with affective disorders, (2) decreased alpha activities in Fp2 and F8 areas in patients with major depression without melancholia, (3) decreased alpha activities in F7 area in patients with bipolar disorder, manic, and (4) increased beta 2 activity in F4 and C4 areas in patients with major depression with melancholia. These results suggest that inter-hemispheric and intra-hemispheric relationships may be disturbed in patients with affective disorder.