The intervention is offered in 6 primary care practices from 3 geographic areas (metropolitan and suburban New York, Philadelphia, and Pittsburgh) and its impact is contrasted to that of 6 comparable practices offering usual care. Patients are selected through an age-stratified, two-stage sampling design and followed for 2 years. The group consists of 1,200 subjects and is comprised of patients with depressive symptoms and signs and a random sample of patients without significant depressive symptomatology. Depression Specialists (DS) collaborate with physicians and help them increase recognition, offer timely and appropriately-targeted treatment recommendations, and encourage patients to adhere to treatment. Beyond direct systematic clinical assessment of patients, information is obtained on health services utilization from practice-based medical records and on cause of death from death certificates. Data are also collected to document the impact of intervention on patient care, and on physician knowledge, attitudes, and satisfaction and test hypotheses derived from preliminary studies of the three Intervention Research Centers (IRCs), Cornell, University of Pennsylvania, and University of Pittsburgh, where the study will be conducted.