Detection of major depressive disorder in primary care patients.

BACKGROUND The aim of this study was to assess the utility of a two-phase case detection strategy for major depressive disorder and a quantitative self-rating instrument for dysphoria. METHODS A convenience sample of 302 ambulatory patients received three self-administered depression rating instruments: a modified version of the Dartmouth Cooperative (COOP) Functional Health Assessment Chart on emotional condition, a three-question screening test for depression taken from the Diagnostic Interview Schedule (DIS), and the Inventory to Diagnose Depression (IDD). All patients' medical charts were reviewed after the administration of these instruments, and those charts of patients found to be depressed were reviewed again 6 months later. A family practice ambulatory patient center in a university hospital was the setting for the study. RESULTS The IDD detected current major depressive disorder in 41 persons (13.6 percent of sample). Twenty-five of the 41 IDD-positive patients had not previously had a major depressive disorder diagnosed according to chart notes. Six months later, 16 of the 25 patients with newly diagnosed major depressive disorders had not returned to the clinic since the index visit. A single question (DIS question 073b), when compared with the IDD diagnosis of major depressive disorder, had a sensitivity of 95.1 percent, specificity of 78.9 percent, positive predictive value of 41.5 percent, and negative predictive value of 99 percent. Dysphoria, as measured by the modified COOP chart on emotional condition, was significantly worse among those with current major depression (IDD positive) than for those without (IDD negative). CONCLUSIONS A two-phase case detection strategy for major depressive disorder consisting of a single screening question followed by a self-administered diagnostic instrument can efficiently pick out virtually all ambulatory primary care patients with a major depressive disorder. A brief functional assessment chart can quantify the extent of dysphoria.