The dexamethasone suppression test and treatment outcome in elderly depressed patients participating in a placebo-controlled multicenter trial involving moclobemide and nortriptyline

Abstract

The dexamethasone suppression test (DST) was conducted in 95 elderly DSM-III-R depressed patients randomized for treatment with moclobemide (MOC; 400 mg daily), nortriptyline (NT; 75 mg daily), or placebo (PBO) in a 7-week double-blind multicenter study. Patients were assessed weekly using various clinical scales, including the 17-item Hamilton Depression Rating Scale. The DST was administered at baseline and at the end of treatment. At baseline, no relationship was found between DST status and the various clinical scales used. At the end of treatment, suppressors (DST-) had significantly improved clinical ratings compared to nonsuppressors (DST+), and were mostly found among those treated with NT (71%) as compared to MOC (41%) or PBO (33%) (p < .03). On the other hand, baseline DST measures influenced treatment outcome; DST+ patients had a greater number of treatment responders to NT (48%) than MOC (19%) or PBO (20%) (p < .07). For DST- patients, the situation was reversed: NT, 7%; MOC, 31%. Postdexamethasone cortisol levels were lower in MOC responders (p < .07). An interaction was found between DST and drug-specific response. The DST may be a useful adjunct for predicting and evaluating the outcome of antidepressant therapy.