Effects of education and culture on the validity of the Geriatric Mental State and its AGECAT algorithm

BACKGROUND: The Geriatric Mental State (GMS) is the most widely used psychiatric research assessment for older persons. Evidence for validity comes from the developed world. AIMS: To assess the validity of GMS/AGECAT organicity and depression diagnoses in 26 centres in India, China, Latin America and Africa. METHOD: We studied 2941 persons aged 60 years and over: 742 people with dementia and three groups free of dementia (697 with depression, 719 with high and 783 with low levels of education). Local clinicians diagnosed dementia (DSM-IV) and depression (Montgomery-Asberg Depression Rating Scale score >/=18). RESULTS: For dementia diagnosis GMS/AGECAT performed well in many centres but educational bias was evident. Specificity was poor in India and sensitivity sub-optimal in Latin America. A predictive algorithm excluding certain orientation items but including interviewer judgements improved upon the AGECAT algorithm. For depression, sensitivity was high. The EURO-D depression scale, derived from GMS items using European data, has a similar factor structure in Latin America, India and, to a lesser extent, China. CONCLUSIONS: Valid, comprehensive mental status assessment across cultures seems achievable in principle.