Antihypertensive drug use and the risk of depression among older hypertensives in an HMO

Background: The iatrogenic effects of antihypertensive drugs have been implicated in the development of depression. The objective of this study was to investigate the relationships between antihypertensive drug dispensings and different measures of depression, with a focus on beta-blockers. Methods: A cohort design was used to study 1,660 hypertensives 65 years and older who were enrolled in the Social HMO project. The dependent measures were: (1) depression diagnosis, (2) number of depressive symptoms, (3) the Center for Epidemiologic Studies-Depression (CES-D) Scale, and (4) antidepressant dispensing. Exposure to antihypertensive medications was obtained from automated prescription dispensing records. Concomitant medical conditions and health status were used as control variables. Results: Elderly hypertensives dispensed beta-blockers [OR = 1.53 (95% CI= 1.06 to 2.22)] or calcium channel blockers[OR = 1.50(95% CI = 1.02 to 2.22)] were more likely to have a diagnosis of depression noted in their medical record. Depressive symptoms noted in the medical record were associated with dispensings for calcium channel blockers or ACE inhibitors, but not for beta-blockers. Risk was greater for both dysthymic mood and excessive lethargy when dispensed calcium channel blockers [OR = 1.60 (95% CI = 1.18 to 2.18)], [OR = 1.49 (95% CI = 1.12 to 1.98)]. Those dispensed beta-blockers [OR 1.36 (95% CI = 1.05 to 1.77)] or ACE inhibitors [OR = 1.74 (95% CI = 1.29 to 2.36)] were at greater risk only for excessive lethargy. Risk of major depressive disorder and beta- blocker use was not significant. Risk of an antidepressant dispensings was greater for patients dispensed betablockers [OR = 1.55 (95% CI = 1.08 to 2.24)] or calcium channel blockers [OR = 1.97 (95% CI = 1.34 to 2.90)]. Conclusion: The findings regarding an association between betablockers and depression depended upon how depression was measured. However, there was no evidence that hypertensives dispensed betablockers were at greater risk for major depressive disorder than hypertensives treated with other antihypertensive medications.