Twenty items assess the frequency of depressive symptoms over the past week, including depressed mood, somatic symptoms, positive affect (reverse-scored), and interpersonal difficulties. The formal name is the Center for Epidemiologic Studies Depression Scale.
Radloff, L. S. (1977). The CES-D scale: A self-report depression scale for research in the general population. Applied Psychological Measurement, 1(3), 385–401.
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