Acute cortisol administration modulates EEG alpha asymmetry in volunteers: relevance to depression.

The acute effects of cortisol (35mg) administration in 11 healthy male volunteers on resting frontal EEG asymmetry measured in the alpha band were investigated, using a within-subjects double-blind design. Results were indicative of a relative increase of right frontal activity with cortisol. This pattern of activity is similar to the deviant pattern that has been reported in patients suffering from depression, a condition often accompanied by elevated plasma cortisol levels. The significant effect on frontal asymmetry provides convergent support for our hypothesis, based upon previous results, that sustained (>30 minutes after stress termination) relative high levels of cortisol inhibit approach motivation.