Cardiovascular risk factors and life events as antecedents of depressive symptoms in middle and early-old age: PATH Through Life Study.Psychosom Med 2009; 71(9):937-43PM
To evaluate cardiovascular risk factors (CVRF) and life events (LE) as predictors of depressive symptoms in a mid-life and an early late-life cohort to determine whether they had independent or interacting effects, and whether there were age differences in the effects.
Cohorts aged 40 to 44 years (n = 2530) and 60 to 64 years (n = 2551) at baseline (Wave 1) were followed up after 4 years (Wave 2) as part of the PATH Through Life Study based in Canberra and Queanbeyan, Australia. Cross-sectional analyses evaluated rates of CVRF and LE in depressed compared with nondepressed participants. Hierarchical generalized linear models were used to evaluate demographic variables, CVRF (diabetes, smoking, alcohol, body mass index, cholesterol medication, hypertension), LE, and Wave 1 depressive symptoms as predictors of depressive symptoms at Wave 2.
At baseline, those with high levels of depressive symptoms were more likely to report smoking, using cholesterol-lowering medications, hypertension, diabetes, past stroke, and higher body mass index. Predictors of depressive symptoms at Wave 2 in the cohort of 40- to 44-year-old persons included Wave 1 depressive symptoms, diabetes, and LE at Wave 2. In the cohort of 60- to 64-year-old individuals, Wave 1 depression, stroke, smoking, low education, and Wave 2 LE predicted depressive symptoms. There was no evidence of interactions between CVRF and LE.
LE and CVRF are independent sets of risk factors for depressive symptoms with different effects in the 40- to 44-year-old and 60- to 64-year-old cohorts. These findings have implications for preventative strategies for depression.