Relationship between alternate-day corticosteroid therapy and behavioral abnormalities.

Three patients with inflammatory or immunologically mediated disease manifested striking behavioral abnormalities in association with long-term alternate-day prednisone regimens. Of particular note was the fact that differences in the abnormalities depended on the day that the patients received their drug: the symptoms that appeared on a treatment day were opposite those present on a day of no therapy. These symptoms were reminiscent of rapid mood cycling in some patients with manic-depressive affective disorder. The phenomenon was dose related and markedly diminished in two patients as the dosage of corticosteroid was decreased, despite the fact that the alternate-day regimen was continued.