The PROSPECT (Prevention of Suicide in Primary Care Elderly - Collaborative Trial) Study evaluates collaborative care for the treatment of current depressive disorders in older primary care patients. Using screening data, we evaluate implications of expanding the focus to additional patients who report taking psychotropic medication or having a history of depression. Some 13.8% of the patients screened were taking a psychotropic medication and 7.3% were both taking an antidepressant and had a Center for Epidemiologic Studies - Depression Scale (CES-D) score of > 15. Patients who reported current antidepressant use and those with a history of depression also had elevated CES-D scores. Conversely, most patients having an elevated CES-D score also reported taking an antidepressant or having a history of depression. These latter criteria for potential caseness yielded a larger number of patients than those identified by the CES-D alone. More comprehensive approaches to the management of depression should attend to patients already taking psychotropic medication and symptomatic patients with a history of depression, as well as those with current syndromal depression.