Depression is a common among palliative care patients but the reported prevalence varies in studies. This is due to the overlapping of the conventional diagnostic criteria with the somatic symptoms in palliative patients. Alternative diagnostic criteria for major depressive disorder (MDD) were introduced. However, the standard method to diagnose depression in palliative setting has not been established.

The aim of this study is to determine the prevalence of MDD among palliative care patients by comparing between four sets of diagnostic criteria.

This is a cross sectional study conducted at two hospitals in Malaysia. Palliative patients were interviewed for presence of depression based on DSM – IV Criteria,Modified DSM – IV Criteria,Cavanaugh Criteria and Endicott's Criteria. They were also requested to complete the Hospital Anxiety and Depression Scale, Distress Thermometer and McGill Quality of Life Questionnaire.

The prevalence of MDD among palliative care patients was the highest for Modified DSM – IV Criteria (23.3%), followed by Endicott Criteria (13.8%), DSM – IV Criteria (9.2%) and Cavanaugh Criteria (5%). It was found that 9 items: DSM – IV Criteria Item 1, 2, 3, 4, 6, 7, and 8; and Endicott Criteria Item 6 and 7 have the ability to differentiate between depressed and non depressed patients. The prevalence based on these 9 items (which we named as ‘Revised’ Diagnostic Criteria) is 10.8%.

The prevalence of depression varies depending on the criteria used. A ‘revised diagnostic criteria’ was formed for more accurate determination of depression in palliative patients.