The dexamethasone suppression and thyrotropin-releasing hormone tests in depressed borderline patients

Borderline patients can be both a diagnostic and a therapeutic enigma. We investigated a group of 24 depressed women with borderline personality disorder or strong borderline features by DSM III criteria for the presence of either an abnormal dexamethasone suppression test (DST) or a blunted TSH response to TRH, abnormalities which have been reported in major depression. Thirteen of the 24 borderlines failed to suppress on the DST, compared with one of 14 normal women (p less than 0.01). Nine of the 24 borderlines had a blunted TSH response to TRH, compared with one of 11 normal women. Neuroendocrine abnormalities were found in a total of 75% of the borderline women, independent of whether or not they met DSM III criteria for major depressive disorder. The results of this study support the notion that many borderline patients with depression have a genuine affective component to their illness, perhaps biologically similar to major depression in non-borderlines.