RIGHT-HEMISPHERE ABNORMALITIES IN MAJOR DEPRESSION - QUANTITATIVE ELECTROENCEPHALOGRAPHIC FINDINGS BEFORE AND AFTER TREATMENT

The quantitative EEGs of drug-free depressed patients were analyzed an d compared to age and sex-matched controls, using spectral analysis. I n addition, QEEGs of depressed patients after clinical improvement res ulting from 6 weeks of antidepressant treatment were also analyzed. Th e subjects were 20 patients suffering from major depression (DSM-III-R ). Scores on the Hamilton Rating Scale for Depression (HRSD) of all pa tients showed a reduction of more than 50% at the end of the 6th week. The results show: (1) delta and theta bipolar absolute powers of the right hemisphere increased in drug-free depressed patients, compared t o controls. (2) No changes in all bands of QEEG were found after clini cal improvement resulting from 6 weeks of treatment. These results sug gest that the right hemisphere plays an important role in major depres sion, and that a reduction in symptoms is not necessarily indicative o f an improvement in underlying major depression.