Mifepristone is an antagonist of type II glucocorticoid (GR-II) receptors, which has shown safety, efficacy, and good tolerability in the treatment of psychotic major depression (PMD). Like BPD, HPA axis hyper-responsiveness appears to play a role in PMD pathophysiology. Belanoff et al. (2002) hypothesized that mifepristone causes a normalizing "resetting" of HPA axis rhythm, accounting for its efficacy in PMD. Mifepristone produces a marked (2- to 3- fold) compensatory increase in central cortisol levels via its antagonism of GR-II receptors. This consequent central cortisol elevation may then be able to counteract abnormally heightened CRH activity via enhanced negative feedback mechanisms.