A validity study of the Hospital Anxiety and Depression Scale in general hospital units and a community sample in Nigeria.

The utility of the Hospital Anxiety and Depression Scale (HADS) as a screening instrument for anxiety and depressive disorders in non-psychiatric units (medical & surgical wards; gynaecology & antenatal clinics of a teaching hospital) and a community sample in Nigeria was investigated. A two-stage screening procedure was employed. This involved the use of GHQ-12/GHQ-30 and HADS against the criteria of a standardised (PSE schedule) psychiatric interview, with psychiatric diagnosis assigned in accordance with ICD-9 criteria. Sensitivity for the anxiety sub-scale ranged from 85.0% in the medical and surgical wards to 92.9% in the ante-natal clinic, while sensitivity for the depression sub-scale ranged from 89.5% in the community sample to 92.1% in the gynaecology clinic. Specificity for the anxiety sub-scale ranged from 86.5% in the gynaecology clinic to 90.6% in the community sample, while specificity for the depression sub-scale ranged from 86.6% in the medical and surgical wards to 91.1% in the ante-natal clinic and community sample. Misclassification rates ranged from 9.9% in the community sample to 13.2% in the medical and surgical wards. Relative Operating Characteristic (ROC) analyses showed the HADS and the GHQ-12 to be quite similar in ability to discriminate between cases (anxiety and depression) and non-cases. The HADS is valid for use as a screening instrument in non-psychiatric units and although initially developed for use in hospital settings, it could be usefully employed in community settings of developing countries to screen for mental morbidity.