Alzheimer's disease

Dementia is a general term that refers to a decrease in cognitive abilities severe enough to impair daily activities. Alzheimer's disease is the most prevalent type of dementia, affecting at least two-thirds of dementia cases in older people.

Alzheimer's disease is a neurodegenerative condition that causes a gradual decline in behavioural and cognitive capabilities such as memory, comprehension, language, attention, reasoning, and judgment. In the United States, it is the sixth leading cause of mortality. Early-onset is rare and occurs in less than 10% of Alzheimer's patients. There is no cure for Alzheimer's disease, although there are treatments available that may alleviate specific symptoms.

Alzheimer's disease symptoms vary depending on the stage of the disease. Depending on the severity of cognitive impairment, Alzheimer's disease is categorized as preclinical or presymptomatic, mild, or dementia-stage. 

Executive functioning impairment can range from minor to severe in the early stages. Then there's a language issue and a loss of visuospatial abilities. Apathy, social isolation, disinhibition, agitation, psychosis, and wandering are prevalent neuropsychiatric symptoms in the mid to late phases.