A comparison af DSM‐III and ICD‐8 diagnoses for major affective disorders and the use of biological markers for depression

The aims of the present study were to investigate the value of adding DSM-III diagnosis and Newcastle Scale Rating to the ICD-8 diagnosis currently used and to investigate the association between Dexamethasone Suppression Test (DST) and the Thyrotropine Releasing Hormone- Thyroid Stimulating Hormone (TRH-TSH) test and the three classification systems for depression. Twenty-six depressed in-patients were included, 17 women and 9 men, with a mean age of 51.5 years. Fourteen patients were psychotic depressed. DST and Newcastle Scale Rating were performed on 18 patients and TRH-TSH test was performed on 16 patients. The addition of DSM-III diagnosis on the 4-digit level did not have any value compared to the ICD-8 diagnosis. However, DSM-III diagnosis on the 5-digit level added important clinical information which corresponded better to Newcastle Scale scores and DST and TRH-TSH test results than ICD-8 diagnosis. The main advantage of the DSM-III classification of depression on the 5-digit level compared to ICD-8 concerns depression on the border between psychosis and neurosis. In clinical practice there is a risk of underestimating the severity of a depression if ICD-8/9 is used as the only criterion for severity. This may have tragic consequences for the patient. This study suggests that rating of the depression on the Newcastle Scale or provision of a DSM-III diagnosis on the 5-digit level are valuable assessment procedures of severity.