The most common type of dementia is Alzheimer’s disease, which makes up 50% to 70% of cases. Other common types include vascular dementia (25%), Lewy body dementia (15%), and frontotemporal dementia.[1][2] Less common causes include normal pressure hydrocephalus, Parkinson’s disease, syphilis, and Creutzfeldt–Jakob disease among others.[10] More than one type of dementia may exist in the same person.[1] A small proportion of cases run in families.[11] In the DSM-5, dementia was reclassified as a neurocognitive disorder, with various degrees of severity.[12] Diagnosis is usually based on history of the illness and cognitive testing with medical imaging and blood work used to rule out other possible causes.[3] The mini mental state examination is one commonly used cognitive test.[2] Efforts to prevent dementia include trying to decrease risk factors such as high blood pressure, smoking, diabetes, and obesity.[1] Screening the general population for the disorder is not recommended.[13]Dementia, also known as senility,[8] is a broad category of brain diseases that cause a long term and often gradual decrease in the ability to think and remember that is great enough to affect a person’s daily functioning.[1] Other common symptoms include emotional problems, problems with language, and a decrease in motivation.[1][2]A person’s consciousness is usually not affected.[1] A dementia diagnosis requires a change from a person’s usual mental functioning and a greater decline than one would expect due to aging.[1][9] These diseases also have a significant effect on a person’s caregivers.[1]
There is no cure for dementia.[1] Cholinesterase inhibitors such as donepezil are often used and may be beneficial in mild to moderate disorder.[14][15][4] Overall benefit, however, may be minor.[4][5] For people with dementia and those who care for them many measures can improve their lives.[1] Cognitive and behavioral interventions may be appropriate.[1] Educating and providing emotional support to the caregiver is important.[1] Exercise programs may be beneficial with respect to activities of daily living and potentially improve outcomes.[16] Treatment of behavioral problems with antipsychotics is common but not usually recommended due to the little benefit and side effects, including an increased risk of death.[17][18]
Globally, dementia affected about 46 million people in 2015.[6] About 10% of people develop the disorder at some point in their lives.[11] It becomes more common with age.[19] About 3% of people between the ages of 65–74 have dementia, 19% between 75 and 84 and nearly half of those over 85 years of age.[20] In 2013 dementia resulted in about 1.7 million deaths up from 0.8 million in 1990.[21] As more people are living longer, dementia is becoming more common in the population as a whole.[19] For people of a specific age, however, it may be becoming less frequent, at least in the developed world, due to a decrease in risk factors.[19] It is one of the most common causes of disability among the old.[2] It is believed to result in economic costs of 604 billion USD a year.[1] People with dementia are often physically or chemically restrained to a greater degree than necessary, raising issues of human rights.[1] Social stigma against those affected is common.[2]
