Trajectories of depressive episodes and hypertension over 24 years: the Whitehall II prospective cohort study.

Prospective data on depressive symptoms and blood pressure are scarce, and the impact of age on this association is poorly understood. The present study examines longitudinal trajectories of depressive episodes and the probability of hypertension associated with these trajectories over time. Participants were 6889 men and 3413 women, London-based civil servants aged 35 to 55 years at baseline, followed for 24 years between 1985 and 2009. Depressive episode (defined as scoring≥4 on the General Health Questionnaire-Depression subscale or using prescribed antidepressant medication) and hypertension (systolic/diastolic blood pressure≥140/90 mm Hg or use of antihypertensive medication) were assessed concurrently at 5 medical examinations. In the fully adjusted longitudinal logistic regression analyses based on generalized estimating equations using age as the time scale, participants in the "increasing depression" group had a 24% (P<0.05) lower risk of hypertension at ages 35 to 39 years compared with those in the "low/transient depression" group. However, there was a faster age-related increase in hypertension in the increasing depression group, corresponding with a 7% (P<0.01) greater increase in the odds of hypertension for each 5-year increase in age. A higher risk of hypertension in the first group of participants was not evident before 55 years of age. A similar pattern of association was observed in men and women, although it was stronger in men. This study suggests that the risk of hypertension increases with repeated experience of depressive episodes over time and becomes evident in later adulthood.