The impact of somatic morbidity on the Hamilton Depression Rating Scale in the very old.

The Hamilton Depression Rating Scale (HDRS) is world-wide the most important observer rating scale for depression. Many items of this scale refer to somatic symptoms of depression which cast doubt on the validity of HDRS scores in the presence of somatic comorbidity as, for example, in elderly patients. The present study, therefore, was planned to investigate the validity of the HDRS in cases in which the patient is suffering from a depressive illness together with somatic illnesses. The study population (n = 516) is a representative sample of citizens aged 70 years and older in West Berlin. They were assessed independently by internists and psychiatrists. Each positive item of the HDRS scale was then rated by the internists as to what degree it reflects somatic morbidity. Results show that multimorbidity interferes with the validity of the HDRS. There were 8 items for which more than half of all positive scores as rated by psychiatrists were seen by the internists as being possibly related to somatic disorders. Patients with corrections in the HDRS score showed a somewhat increased rate of medicines and cardiovascular diagnoses. There was less ambiguity for items with greater severity.