Reliability and validity of the Danish version of the Calgary Depression Scale for Schizophrenia

Depressive symptoms within the range of schizophrenic syndromes constitute a major diagnostic and therapeutic problem. Earlier research has indicated that available depression scales are not adequate when examining mood disturbances in patients with schizophrenia. We have made an attempt to estimate the reliability and validity of the Danish version of the Calgary Depression Scale for Schizophrenia. The external validity has been analysed in relation to the Major Depression Inventory (MDI). The internal validity has been analysed by using Loevinger's coefficient of homogeneity as the primary statistic. For the inter-observer reliability the intra-class coefficients have been calculated. It was shown that a subscale of the Calgary scale has sufficient reliability and validity.