Delirium, depression, and dementia are some of the most common psychological diagnoses in older adults today. It is difficult to distinguish the three Ds in the elderly because they overlap with each other and can all exist at the same time in the same patient. Delirium, dementia and depression all affect the quality of life of older adults and often increase mutual risks (Downing, Caprio & Lyness, 2013). For the purposes of this article I will focus mainly on dementia diagnosis, prevention and nursing measures associated with it, but first I would like to distinguish between delirium and depression because dementia is often associated with the two in the elderly. population.Delirium is a cognitive disorder that alters the level of consciousness of patients, generally with acute onset, impairs memory, fluctuations in behavior, produces disorganized thinking and perceptual disturbances such as hallucinations (Downing, Caprio & Lyness, 2013). To diagnose and monitor Delirium, a Confusion Assessment Method (CAM) is used to measure Delirium symptoms ...