Dementia: Definition, Overview, and Global Epidemiology

What is Dementia? Dementia is a chronic and progressive clinical syndrome caused by various diseases that damage the brain, leading to significant decline in cognitive abilities and loss of functional independence. The term derives from the Latin demens, meaning “out of one’s mind,” though modern understanding emphasizes its neurological basis rather than purely mental illness. Dementia affects: • Cognition memory, language, reasoning, visuospatial skills • Functionality ability to perform everyday activities • Behaviour and personality mood, emotions, social interactions Importantly, dementia is not a part of normal aging. While some cognitive changes are typical with age, dementia involves pathological decline beyond normal expectations for a person’s age and education level.