Getting what you ask for: on the selectivity of depression rating scales

A large number of rating scales has been developed to assess depression severity and change during antidepressant therapy. When reviewing the literature, the choice of the rating scales used in a particular study often seems arbitrary. The most frequently used observer rating scales, the Hamilton Depression Rating Scale (HDRS) and the Montgomery-Asberg Depression Rating Scale (MADRS), and the most frequently used self-rating scale (the Beck Depression Inventory, or BDI) were developed more than 20 years ago. Their historical background is too often forgotten and they are reflections of their origin: the HDRS and the MADRS reflect antidepressant activity while the BDI reflects psychotherapy. Moreover, the HDRS is at risk of putting 'all depressions in one basket', while the MADRS is at risk of putting 'all antidepressants in one basket'. Therefore, the question whether a particular antidepressant could be more effective in a particular subtype of depression cannot be answered. Observer rating scales are more frequently used than self-rating scales, and when scales are used that do exist in an observer rating and a self-rating version, interesting differences are found. The present paper does not suggest that one scale is better than another, but suggests that a better knowledge of their differential background can help the researcher choose the correct scale for his purposes.