Statistical quantitative EEG studies of depression, mania, schizophrenia and normals

The EEG characteristics of 63 depressive psychotics, 75 manics and 53 schizophrenic patients, consecutive admissions satisfying research criteria, are presented. Statistical comparisons between the psychotic groups and of each psychotic group against 60 normal controls (all dextral) were undertaken for power, coherence and phase characteristics in the 8-13 Hz frequency band. The characteristic EEG-myogenic power spectra for frequencies up to 60 Hz, expressed as the log of the right/left parietal and temporal power ratios for the four groups are also graphically displayed. The results suggest the presence of increasing disorganization of the right hemisphere (least in depression, intermediate in mania and maximal in schizophrenia) together with left hemisphere disorganization (in both mania and schizophrenia; again maximal in schizophrenia).