Abstract
Increases in the number of elder population will have a profound impact on the old age associated problem. Common psychiatric disorder and cognitive dysfunction seen in aging persons are depression and dementia, that also the great challenge for clinician to accurately differentiate and diagnose. Elder people may not express low mood by themselves even though depression had persisted for a period of time. Multiple physical complaint may mask the true psychiatric illness as depression, leading to confusion or misdiagnosis as internal medical program by clinician, thus delay the appropriate treatment. On the other hand, mild cognitive impairment share many similar clinical presentation as depression. The accurate differential diagnosis is based on distinct characters of different disease course, and earlier intervention could refrain from mild cognitive impairment entering into dementia. We highlight that clinical practitioner, nursing staff, main care giver and geriatric doctor all have to learn more about this issue. The role of comprehensive geriatric assessment (CGA) for elder people help increasing correct diagnosis of depression or cognitive dysfunction, and benefit maintaining activities of daily living, also prevent from functional decline and improve quality of life.