Poor efficacy of the hospital anxiety and depression scale in the diagnosis of major depressive disorder in both medical and psychiatric patients

The Hospital Anxiety and Depression scale (HAD) is a brief questionnaire which was designed to indicate the likely presence of a depressive disorder in medically ill patients. However, more recently it has been used in several research studies to determine the presence of depression in both medical and psychiatric patients. The aim of the present study was to validate the usefulness of the HAD when used in this way. The HAD was compared to DSM-III-R diagnoses of major depressive disorder in 153 medical in-patients and 147 psychiatric out-patients. In both groups the sensitivity of the HAD was between 80 and 100% using the cut-off point of 8. However, the positive predictive value (PPV) of the HAD was only 17% in medical patients and 29% in psychiatric patients. Changing the cut-off point for depression or using the total HAD score did not significantly improve the PPV. These findings suggest that the HAD does not accurately determine the presence of DSM-III-R major depressive disorder in medical or psychiatric patients, and should not be used as a research instrument for this purpose. Nonetheless, the HAD should still be used for its original purpose, namely as a clinical indicator as to the possibility of a depressive disorder.