Objective: To examine the hypothesis that hypothalamic-pituitary-adrenal (HPA) axis function is a trait abnormality in bipolar disorder.
Method: We examined HPA axis function in a pilot study of five patients with rapid-cycling bipolar disorder in both relapse and remission using the dexamethasone/corticotropin releasing hormone (dex/CRH) test.
Results: The cortisol response to the dex/CRH test correlated significantly between the 2 tests (r = 0.997; p < 0.0005).
Conclusion: The data suggests that the cortisol response to the dex/CRH test is stable over time and independent of mood state.