Siddiqui-Shah Depression Scale (SSDS): Development and Validation

The purpose of the study was to develop and validate a self-report scale to measure depression in both clinical and non-clinical Pakistani populations. The 72 items obtained from university students were judged for their relevance to depression by psychiatrists and clinical psychologists. An approximate 50% consensus among judges was taken as the selection criterion. The 36 items so obtained were split into two equivalent halves and tested on clinical as well as non-clinical populations. The split half reliabilities of the scale with Spearman-Brown correc tion were r = 0. 79 and r = 0.84 for the clinical and r = 0.80 and r = 0.89 for the non-clinical samples respectively. The Alpha coefficients for the clinical and non-clinical samples were 0.91 and 0.89 respectively. The scale correlated sig nificantly with Zung's Depression Scale, r = 0.55 (p < .001) and psychiatrists' rat ings of depression r = 0.40 (p < .05). The scale showed a significant correlation with subjective mood ratings for the clinical group r = 0.64 (p < . .001) as com pared to the non-clinical group r = 0.14 (p: n.s.). The scale also demonstrated high sensitivity and specificity. The percentiles and cut-off scores for the clinical as well as non-clinical groups have been determined.