OBJECTIVE: This study was done to compare the effects of 6-week
treatment with amitriptyline on hypothalamic-pituitary-adrenocortical (HPA)
regulation in elderly depressed patients and age-matched comparison
subjects. METHOD: A combined dexamethasone-suppression/CRH- stimulation
(dexamethasone/CRH) test was administered before initiation of
amitriptyline treatment and at the end of weeks 1, 3, and 6 of treatment.
Thirty-nine depressed inpatients, mean age = 69 years, completed the study.
Fourteen normal volunteers, mean age = 67 years, served as comparison
subjects. RESULTS: In relation to the comparison subjects, the depressed
patients had a profoundly abnormal HPA response, in particular an
exaggerated cortisol release in the dexamethasone/CRH test. This
abnormality began to disappear after 1 week of treatment with
amitriptyline. In contrast, amitriptyline did not affect neuroendocrine
regulation in the comparison subjects at any time during the test period.
CONCLUSIONS: The data suggest that amitriptyline affects HPA regulation in
hypercortisolemic depression only, and they raise the possibility that
normalization of its feedback control is related to the antidepressive
effect of amitriptyline.