High blood pressure is related to depression in elderly subjects

A positive association between hypertension and depression has been reported in some inquiries but not in others, and the relationship was limited to individuals with diastolic blood pressure (DBP) in some studies.

Methodological difficulties are observed in previous research: some studies are based on self-reported hypertension, adjustment for potential confounders is not systematic and the use of a standardized psychiatric diagnosis is not common. This study tests the hypothesis of a positive association between hypertension and depression, and tries to circumvent the described methodological difficulties.

A large, stratified random sample of individuals from the census list aged 55 and over was selected. An epidemiological screening design was implemented, and standardized Spanish versions of assessment instruments were used, including the Geriatric Mental State (GMS), its computerized diagnostic program, AGECAT, and the History and Aetiology Schedule. The history of medical diseases was documented by means of the Risk Factor Questionnaire designed by the EURODEM Workgroup. The assessment of blood pressure followed World Health Organization standards, modified by the European Society of Hypertension, and Joint National Committee Seventh Report criteria were used for the diagnosis of hypertension. The specific hypothesis of the association of hypertension with depression was tested by means of logistic regression (LR) analysis.

At the end of the investigation, hypertension was documented in 2,523 individuals (61.0%; 41.7% were stage 1 and 19.3% were stage 2 hypertensives), and 314 of them (12.4%) were depressed. Results of LR analysis show, in the unadjusted model, that OR for depression was significantly higher in stage 2 hypertension (OR = 1.46, 95% CI = 1.12–1.90).

The results support the hypothesis that depression is secondary, since the association was found with moderate/severe hypertension (stage 2), but not with mild hypertension (stage 1). Prospective, sound longitudinal research is now needed to confirm the potential of hypertension at baseline to increase the risk for incident depression.