Psychiatric disorders of the elderly are significantly increasing in importance. Moreover, Korea is transitioning more rapidly to an aged society than any other country in the world. Psychiatric disorders of the elderly include typical dementia, depression, anxiety, late-life psychosis, and sleep disorders. Patients also may need to see a geriatric psychiatrist for chronic pain, Parkinson's disease, heart disease, diabetes, stroke, or other medical disorders. Older adults have special physical, emotional, and social needs. The principle therapeutic guidelines for elderly psychiatric disorders are based on comprehensive diagnosis and treatment including co-existing medical illnesses and medications, family, social and environmental issues. An integrated paradigm for prevention, diagnosis, rehabilitation, and multidisciplinary approaches are essential. We reviewed the literature on the background, classification, diagnosis, and treatment of psychiatric disorders of the elderly. Treatment was classified into pharmacological and non-pharmacological intervention. Psychiatric disorders of the elderly covers from brain to community based on being able to treat elderly disorders successfully and improving quality of life.