Subsyndromal depression in old age: clinical significance and impact in a multi-ethnic community sample of elderly Singaporeans

Abstract

This cross-sectional study examined the clinical significance and impact of subsyndromal depression in a sample of elderly people living in the community in Singapore. Data were analyzed from a population survey (the Singapore National Mental Health Survey of the Elderly). A total of 1092 respondents from a nationally representative multi-ethnic (Chinese, Malay and Indian) stratified random sample of older adults aged 60 and above were examined for depression using the Geriatric Mental State Examination (GMS). Diagnostic confidence levels of 3-5 indicated a DSM-IV diagnosis of syndromal depression, and 1-2 indicated subsyndromal depression. Other variables included sociodemographic characteristics, psychiatric and medical comorbidities, MMSE, health awareness, health and functional status. Subjects with subsyndromal depression were more likely to have poor socioeconomic status, cognitive impairment, anxiety, and measures of poor mental, physical and functional status compared with non-depressed subjects, and were similar to or worse than syndromal cases. In multivariate analyses that controlled for age, gender, ethnicity, education and several other sociodemographic factors, both subsyndromal and syndromal depression were significantly associated with higher numbers of medical comorbidities, diagnoses of comorbid dementia and anxiety, lower MMSE scores, self-reported mental health problem, functional disability and poor health status. In this Asian population, subsydromal depression had the same clinical significance and health impact as syndromal depression, similar to findings in the West.