The effect of mild to moderate dementia on the Geriatric Depression Scale and on the General Health Questionnaire.

The Geriatric Depression Scale (GDS) and two versions of the General Health Questionnaire (GHQ 28 and corrected GHQ 28) were administered to 111 patients admitted to an acute geriatric medical unit. Depression and dementia were diagnosed by semi-structured interview using DSM III criteria. There was no statistically significant difference in the three scales between cognitively normal depressed patients and demented depressed patients. The three scales were sensitive indicators of depressive illness (greater than 90%), but the GHQ 28 and CGHQ 28 needed adjustment of their community-based threshold values.