Prevention of late-life depression in primary care: Do we know where to begin?

Objective: This study attempted to compare two models for selective ( people at elevated risk) and indicated ( those with subsyndromal depressive symptoms) prevention and to determine the optimal strategy for prevention of late- life depression. Method: Onset was assessed at 3 years with the Geriatric Mental State AGECAT in a randomly selected cohort of 1,940 non-depressed and non-demented older people in Amsterdam. Risk factors that can easily be identified in primary care were used. Results: The association of risk factors with depression incidence was expressed in absolute and relative risk estimates, number needed to treat, and population-attributable fractions. Prevention models were identified with classification and regression tree analyses. In the indicated prevention model, subsyndromal symptoms of depression were associated with a risk of almost 40% of developing depression and a number needed to treat of 5.8, accounting for 24.6% of new cases. Adding more risk factors raised the absolute risk to 49.3%, with a lower number needed to treat but also lower attributable fraction values. In the selective prevention model, spousal death showed the highest risk, becoming even higher if the subjects also had a chronic illness. Overall, the attributable fraction values in the indicated model were higher, identifying more people at risk. Conclusions: Consideration of the costs and benefits of both models in the context of the availability of evidence-based preventative interventions indicated that prevention aimed at elderly people with depressive symptoms is preferred. The focus on treatment should be readdressed; a new approach is needed, with a stronger emphasis on prevention.