Cortical Evoked Potentials and Clinical Rating Scales as Measures of Depressive Illness

32 adults with major depressive disorder completed the Hamilton Rating Scale for Depression, Beck Depression Inventory, Present State Examination & Newcastle scale & had contingent negative variation, postimperative negative variation & auditory evoked potential measured before & during antidepressant drug treatment. There were close correlations between all rating scales suggesting that the common variance between them related to the severity of depression.