Prediction of depressive relapse in remitted bipolar patients using corticotrophin‐releasing hormone challenge test

Abstract
Abnormalities in corticotrophin (ACTH) and Cortisol levels before and after corticotrophin‐releasing hormone (CRH) stimulation have been reported in depressed bipolar patients. The ACTH and free Cortisol response to the injection of 100 ug of synthetic human CRH and plasma cortisol‐binding globulin (CBG) levels were measured in 42 lithium‐treated patients suffering from RDC bipolar‐I disorder in remission, and in 21 age‐ and sex‐matched control subjects. A 1‐year follow‐up was conducted in order to assess any possible relationship between outcome and the hormonal response. Bipolar patients showed higher baseline and peak ACTH concentrations than controls. A lower net area under the ACTH concentration curve after CRH stimulation predicted depressive relapse within 6 months by multiple regression analysis. The CRH challenge test could be a potentially good predictor of depressive relapse in remitted bipolar patients.