Since the classical observations made by Addison on disturbances occurring in patients suffering from adrenocortical insufficiency, various neurological and mental alterations have suggested that the vital hormones are essential for normal function of the central nervous system. The mental changes in these patients consist among others of irritability, unexplained bursts of anger, disturbed sleep with nightmares, depression, periods of amnesia and unreality, and occasionally hallucinations and paranoid psychosis.1-4Some of the patients exhibit motor and sensory disturbances, changes in reflexes, pupillary and visual abnormalities, drowsiness, and confusion, which is occasionally accompanied by convulsions.1-3Among other abnormalities described in hypoadrenalism are slowing of the EEG in patients1,2,5,6and experimental animals7and an increase in brain excitability of the latter,8,9as determined by the threshold for electrically induced seizures. Various metabolic derangements in the central nervous system have been described in hypoadrenalism,9but there is very