In this study an evaluation of the inter-rater reliability of the Hamilton Depression Rating Scale, the Melancholia Scale and the Montgomery-Asberg Depression Rating Scale has been carried out. Furthermore, the inter-item correlations of these scales have been investigated in relation to diagnostic ratings. It was found that the quantitative scales had satisfactory inter-rater relationship. Only low agreement was found between the quantitative and diagnostic scales, as expected, while there was high agreement between the quantitative scales. The relevance of introducing new scales and the definition of major depression are discussed.