References:
Hann, D., Winter, K., & Jacobsen, P. (1999). Measurement of depressive symptoms in cancer patients: Evaluation of the Center for Epidemiological Studies
(CES-D). Journal of Psychosomatic Research, 46, 437-443.
Radloff, L. S. (1997). The CES-D scale: A self-report depression scale for research in the general population. Applied Psychological Measurement, 1, 385-401.
Score is the sum of the 20 item weights. Possible range is 0-60. If more than four questions are missing answers, do not score the CES-D. A score of 16 or more is considered depressed.