Objectives: To translate and validate the Sinhala version of the Centre for Epidemiological Studies Depression scale (CES-D) for diagnosing depression in out-patients.
Design: A combined qualitative and quantitative approach was used for the translation of the CES-D. Sample size was calculated to detect a targeted sensitivity and specificity of 85%. The sample consisted of 75 participants diagnosed with major depressive disorder according to DSM IV criteria and 75 gender matched controls. Criterion validity was assessed using receiver operating charact-eristic (ROC) analysis. The Structured Clinical Interview for DSM-IV (SCID-II) conducted by a psychiatrist was used as the gold standard.
Results: Mean age of the sample was 33 years. There were 91 females (60.7%). There was significant difference in the mean CES-D scores between cases (13.94) and controls (6.58) [t=14.50, df=148, p<0.001]. A score of ≥ 16 gave a sensitivity of 84% and specificity of 92%. A score of ≥ 21 gave a sensitivity of 73.3% and specificity of 96%. The Cronbach's alpha was 0.93. The four items that were reverse coded had poor correlation with total scores. The average correlation coefficient for the reverse-scored items was 0.35 and for the rest of the items 0.63. Principal component analysis with oblique rotation identified four factors. Factor 1 corresponds to the "depressed affect" and "somatic complaints" in the original model proposed by Radloff. Factor 2 corresponds to the interpersonal concerns. Factors 3 and 4 loaded the reversed coded items.
Conclusions: The Sinhala version of the CES-D is a valid and reliable instrument for diagnosing major depressive disorder.