Plasma Dexamethasone Concentration and Cortisol Response during Manic Episodes

Background:Despite the widespread study of the dexamethasone suppression test (DST) in patients diagnosed with major depression, it has been less well studied during manic and mixed states of bipolar disorder. Methods:Cortisol response to the administration of 1 mg of dexamethasone was studied in 44 patients diagnosed bipolar disorder, manic (n = 37) or mixed (n = 7). Dexamethasone levels and cortisol responses were compared between these groups. Four patients initially meeting criteria for bipolar disorder, mixed, and 7 patients initially meeting criteria for bipolar disorder, manic, all of whom were characterized as DST nonsuppressors, were retested after remission. Results:Dexamethasone levels were lower and cortisol levels higher in those patients diagnosed bipolar disorder, mixed. An inverse correlation was found between log-transformed dexamethasone levels and log-transformed cortisol levels at 3 (r = −.619, p ≤ .001) and 10 (r = −.501, p ≤ .001). In those subjects retested after remission, dexamethasone levels were higher and cortisol levels lower than during the manic and mixed states. Conclusions:Disturbances in the hypothalamic-pituitary-adrenal axis are observed frequently during mixed states of bipolar disorder, but are also not uncommon in purely manic episodes. These changes appear to be state dependent and revert with treatment.