Methodological aspects in the assessment of severity of depression by the Hamilton Depression Scale.

Observer-rating scales are used for the evaluation of drug trials in depression. One of the most widely used depression rating scales is still the Hamilton Depression Scale (HAMD), which was developed at the time when the first antidepressants were becoming available. Due to its construction it seems to have a specific focus on drug effects of classical antidepressants. As a result of different methodological analyses such as principal component analysis, the Rasch model and facet analysis, a differentiation between core symptoms reflecting the severity of depression and additional symptoms describing other aspects of the symptomatology of depression seems meaningful. The use of the HAMD 6-item score, described primarily by Bech, as the main efficacy criterion in antidepressant drug trials gives a fair estimation of drug-induced changes of severity of depression and avoids bias such as the well-known bias of the HAMD total score in favour of tricyclic antidepressants. This is demonstrated by the evaluation of two sertraline-amitriptyline comparative studies.