Dementias

Dementias are a group of progressive brain disorders characterized by a decline in memory and other cognitive functions severe enough to interfere with daily life. Dementia is not a single disease; it describes a set of symptoms that can arise from various diseases or conditions. The most common causes are Alzheimer's disease, vascular dementia, Lewy body dementia, and frontotemporal dementia, often occurring in combination as mixed dementia.

Common symptoms include memory loss, language difficulties, impaired executive function, visuospatial problems, and changes in mood or behavior. Symptoms evolve over time and vary by type. Diagnosis typically involves clinical history, neurological examination, cognitive testing, and laboratory tests to rule out reversible conditions; brain imaging (CT or MRI) is used to identify patterns of atrophy or vascular damage. In some cases, lumbar puncture or PET imaging may be used. Diagnosis is based on established criteria and may require longitudinal observation.

There is no cure. Treatments aim to manage symptoms, slow progression in some cases, and support function and safety. Medications such as cholinesterase inhibitors and memantine may help with symptoms in some people, particularly with Alzheimer’s disease. Nonpharmacological approaches, including cognitive stimulation, physical activity, social engagement, sleep management, adequate nutrition, and caregiver education, are important. Management also involves treating cardiovascular risk factors and comorbid conditions, planning for daily care, legal and financial decisions, and ensuring safety at home.

Prognosis is highly variable and depends on the underlying disease, age, and health. Dementias typically worsen over years, leading to increasing dependency. The condition imposes substantial caregiving needs and healthcare costs. Public health efforts emphasize risk reduction through control of blood pressure, cholesterol, diabetes, smoking cessation, physical activity, and healthy diets.

Dementias are most common in older adults and become more prevalent with age. Risk factors include age, family history, and genetic factors; modifiable risks include cardiovascular disease, diabetes, obesity, physical inactivity, and smoking.