There is a gap between the efficacy of treatments for late-life depression under research conditions and the effectiveness of treatments as they occur in the "real world" of primary care. Considerable evidence supports the efficacy of treatments for late-life depression, but many depressed older adults either are not recognized or do not receive effective treatment for depression in primary care. Older adults face a range of special treatment barriers: knowledge deficits; losses and social isolation; multiple medical problems; and lack of financial resources. More research is needed to understand these barriers and to study the effectiveness of multifaceted, population-based disease management interventions for late-life depression in primary care.