Psychometric properties of the Zung Self-Rating Depression Scale.

Some psychometric parameters of the instrument were estimated using a sample of depressed patients and a sample of normal subjects from the Czech population. The findings considerably support the hypothesis that the SDS items belong to the same psychometric family. Most items and the scale as a whole show a remarkable ability to discriminate between normal subjects and those suffering from depressive disorder. The result also rather convincingly indicate the SDS capacity to monitor changes of depressive disorder symptoms during treatment to be rather independent of relatively stable personality traits as measured by the EPQ. It might be concluded that the SDS psychometric parameters qualify the instrument for measurement of milder forms of depressive disorder in the Czech population.