Dementia affects a person’s cognitive abilities and functioning. Learn about how the syndrome is caused, who it affects and why it affects them.

Dementia is a clinical syndrome involving cognitive impairment that disrupts social and occupational functioning. Dementia can be caused by a variety of diseases, with Alzheimer’s disease being the most common form. Dementia is generally associated with old age, and there is a growing concern about a global epidemic of dementia. This is because of rising dementia trends in older people as well as increased life expectancy. Awareness of the facts and statistics regarding dementia can help with diagnosing and treating the condition.

Prevalence of Dementia

In 2019, the number of people living with dementia in the United States is estimated to be 5.8 million. The majority is made up of people aged 65 and over. The elderly are estimated to account for 5.6 million cases, with 10% of the total elderly population suffering from dementia. In terms of dementia demographic trends, about two-thirds of Americans suffering from dementia are women, and African-Americans are twice as likely to suffer from dementia. Hispanic people also have a higher dementia prevalence rate and are one-and-a-half times more likely to develop it.

Education and income levels, especially during the early years, are known to contribute to the risk of developing dementia. Age also influences the incidence of dementia. After the age of 65, the rate of dementia doubles every five years. The prevalence of dementia between the ages of 65 to 74 is 3%. This rate rises to 17% for the 75 to 84 age group and reaches its peak at 32% in individuals over 85.

Dementia in the United States

United States dementia statistics indicate that over the last two to three decades, U.S. dementia rates are dropping. The rate of dementia in the United States changed from 11.6% to 8.8% between 2000 and 2012, and the decline rate is estimated to be between 1% to 2.6%. Although there has been a decline in dementia rates, growth in the elderly population is expected due to an increase in life expectancy and because of baby boomers reaching old age. As a result, the number of people suffering from dementia in the United States is expected to rise from 5.8 million to 13.8 million by 2050.

Rates of Dementia Worldwide

According to the World Health Organization, the incidence of dementia rates worldwide is estimated to be around 50 million. Dementia statistics by country indicate that around 60% of people with dementia live in developing countries. This number is projected to increase as the elderly population increases in countries like China and India. These developing countries are expected to contribute to 71% of dementia cases around the world by 2050. Currently, East Asia has the highest prevalence of dementia, with around 9.8 million people living with the condition. East Asia is followed by Western Europe (7.5 million), South Asia (5.1 million) and North America (4.8 million).

The percentage of elderly individuals with dementia has been declining in many high-income countries, such as the United States, the Netherlands and England. However, elderly population growth is trending upward globally, and the number of dementia cases is expected to increase. Dementia remains severely underdiagnosed in many developing countries, with almost 90% of cases in India remaining undiagnosed. There have been higher dementia rates in Western countries, but this trend is probably due to underdiagnosis elsewhere.

Age of Diagnosis

Although dementia is generally associated with old age, dementia can also occur in younger individuals. Dementia occurring in adults below 65 years of age is referred to as early-onset dementia. Statistics on dementia in different age groups indicate that dementia in individuals over the age of 65 has a prevalence of about 6.4%, and the incidence of dementia doubles every five years after 65. The average age of dementia diagnosis is 83.7 years in the United States.

A study conducted in the United Kingdom found that early-onset dementia accounts for about 2.2% of all dementia cases. However, an estimate by the World Health Organization suggests that this number may be much higher (6% to 9%). Some health care professionals do not expect younger individuals to develop dementia, and they may miss the symptoms. This results in dementia being undiagnosed for much longer. Early-onset dementia is associated with the presence of other mood disorders and higher stress levels.

Common Forms of Dementia

The major types of dementia include Alzheimer’s disease, vascular dementia and Lewy body dementia:

  • Alzheimer’s disease: The prevalence of Alzheimer’s disease is the highest of all types of dementia, accounting for about 60% to 70% of all cases. Alzheimer’s disease involves global cognitive decline involving memory, reasoning, speech and orientation. Statistics on Alzheimer’s disease indicate that it is the sixth leading cause of death in the United States, and a 14% increase in Alzheimer’s rates is expected in the country.
  • Vascular dementia: Vascular dementia is caused by cerebrovascular diseases that damage blood vessels in the brain. This results in reduced oxygen supply to brain regions and subsequent neuron damage. Vascular dementia statistics show this is the second most prevalent cause of dementia. The prevalence rate for vascular dementia is 20% to 30% of all cases.
  • Lewy body dementia: Lewy body dementia occurs when α synuclein proteins are deposited into neurons in the brain regions that coordinate movement. Statistics on Lewy body dementia indicate a prevalence rate of about 5%.

Dementia Risk Factors

The exact causes and risk factors of dementia are unknown, but dementia involves a combination of genetic and environmental factors along with lifestyle choices and habits.

  • Obesity: Obesity is a predictor of diabetes and is associated with cardiovascular diseases. Diabetes and cardiovascular diseases are risk factors for cognitive impairment, and there is a link between obesity and dementia risks later in life.
  • Smoking: People who smoke cigarettes are at an increased risk of developing dementia. Depending on the study, smoking can increase the risk of developing dementia by 40% to 80%. This relationship is only true for current smokers and not for individuals who quit smoking. Smoking is associated with a higher risk of developing cardiovascular diseases and can also increase oxidative stress and inflammation. All these factors may be responsible for the link between smoking and dementia risks.
  • Diabetes: Diabetes and dementia risks are related. Individuals with diabetes are at a higher risk of developing dementia, including Alzheimer’s disease and vascular dementia. Diabetes involves changes in insulin and glucose levels and is also associated with a higher risk of developing cardiovascular diseases. These factors may be responsible for the association between diabetes and dementia.
  • Down syndrome: Down syndrome is caused by the presence of an extra copy of chromosome 21. This chromosome carries the gene that codes for the protein that is responsible for forming amyloid plaques in Alzheimer’s disease. These plaques are considered to be neurotoxic and partly responsible for the symptoms of Alzheimer’s disease. Dementia is common in Down syndrome. At least half of the individuals with Down syndrome are likely to develop dementia due to Alzheimer’s disease in adulthood.
  • Alcohol use: Alcohol consumption and dementia are linked in a few different ways. Although low-levels of alcohol intake are linked with a lower risk of dementia, abstinence and heavy alcohol use are linked with a higher risk. Prolonged and heavy use of alcohol can directly lead to permanent damage to the brain and cause dementia. Alcohol-induced dementia may also occur due to thiamine deficiency. Thiamine is necessary for neurons to utilize energy, and a deficiency can cause neuronal damage.

Dementia Mortality Rate

Dementia is the sixth highest cause of death in the United States and the fifth highest cause of death among the elderly. According to a 2017 report on dementia death statistics, dementia accounted for 261,914 deaths in 2017. This means that dementia accounted for 66.7 deaths per 100,000 total deaths in the United States, which was more than twice the rate in 2000 (30 deaths per 100,000).

The dementia mortality rate was higher in females, at 72.7 deaths per 1000,000 compared to males at 56.4 deaths per 100,000. Alzheimer’s disease accounted for 46% of all deaths due to dementia in 2017. The mortality rate of dementia in people aged 65 to 74 was 56.9 deaths per 100,000 and 2,707 deaths per 100,000 in people aged over 85.

Economic Impact of Dementia

People with dementia require increased supervision over time due to their declining ability to do daily activities independently. The later stages of the disease require full-time supervision due to a total loss of functional autonomy. This means that the cost of dementia care involves social care in addition to medical care. The cost of dementia treatment in the United States in 2019 is estimated to be about $290 billion, which is expected to rise as the elderly population increases.

Globally, the financial impact of dementia treatment is estimated at about $818 billion per year and accounts for about 1% of the global GDP. The lifetime cost of care for a U.S dementia patient was estimated to be around $196,002 in 2017. Most of the financial burden of dementia treatment is shouldered by family members. Unpaid in-home dementia care costs made up for 72% of the costs, and out-of-pocket expenses for medical treatment accounted for 14% of the total cost. A similar trend has been observed in other developed countries, but not in developing countries where social care is considerably less expensive.

Impact on Caregivers

Caregivers are often required to help dementia patients with daily activities like paying rent and transportation as well as basic activities like bathing and dressing. Most caregivers tend to be family members or friends, with unpaid caregivers accounting for 83% of the help. In 2017, unpaid caregivers spent an average of 21.9 hours per week providing care for dementia patients. This unpaid care was worth an economic value of about $232.1 billion for the entire year.

Although almost 45% of unpaid caregivers find that providing care to dementia patients is rewarding, many suffer from stress and depression. Regarding their relationship with the patient, unpaid caregivers may find it difficult to cope with the patient’s loss of memories. Statistics on dementia caregivers indicate that twice as many caregivers for dementia patients experience financial, emotional and physical difficulties compared to caregivers for people without dementia. The rate of depression (30% to 40%) in dementia caregivers tends to be higher than that in age-matched controls (5% to 17%). Similarly, statistics about dementia caregiver stress show they also experience higher levels of stress and anxiety, which can adversely affect their physical health. About 59% of caregivers for dementia suffer from high emotional stress.

Statistics on Dementia Treatment

Dementia is an irreversible, progressive brain disorder that has no cure available at this time. Fortunately, early diagnosis and treatment can help manage the symptoms and slow down the rate of cognitive decline. The prognosis of dementia depends on the particular type of dementia. Individuals with Alzheimer’s disease have a life expectancy of between eight to 10 years after the initial diagnosis, but there are cases of individuals surviving up to 20 years. Similarly, individuals with Lewy body dementia have a life expectancy of eight years.

The life expectancy of individuals with vascular dementia is much more variable and depends on the extent of damage caused by the disease. Although there is considerable ongoing research for the treatment of dementia, the failure rate of clinical trials has been over 99%. Furthermore, only four drugs (memantine and three cholinesterase inhibitors) have been approved for the treatment of dementia in the last 20 years.

Ongoing Research

Finding new treatments is currently a priority, but finding effective methods for the early diagnosis of dementia is also necessary. There is ongoing research to identify biomarkers for the easy and early diagnosis of dementia. Biomarkers are biological factors that indicate the presence or absence of disease.

Currently, big data approaches are being applied to identify markers for diagnosis and treatment of dementia. Besides biomarker identification, some recent dementia studies and research approaches for treatment include:

  • Drugs that target amyloid plaques: Although some drugs directed at preventing amyloid plaques have failed, there is ongoing research on drugs that inhibit a protein called Fyn kinase that interacts with the β amyloid protein. The interaction between the Fyn protein and amyloid protein is considered to be responsible for neuronal degeneration in Alzheimer’s disease.
  • Anti-inflammatory agents: Alzheimer’s disease is accompanied by mild inflammation of neurons. Drugs that inhibit cells involved in causing inflammation are currently being tested.
  • Targeting insulin: Insulin can prevent cognitive decline, and it has been found to have neuroprotective effects. Drugs that cause insulin to release are currently being tested for the treatment of Alzheimer’s disease.
  • Stem cell therapy: Studies on stem cells are currently being conducted for their capacity to regenerate neurons damaged by dementia.

Individuals with substance use disorders are often at an increased risk of developing dementia. In addition, some people may suffer from dementia and substance use disorder at the same time. Caregivers may also turn to substances to deal with the stress of caring for their loved one. If you or a loved one is suffering from addiction and a co-occurring mental health condition, The Recovery Village can help. Contact us today to learn more about treatment plans that can work well with your situation. 

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Editor – Jonathan Strum
Jonathan Strum graduated from the University of Nebraska Omaha with a Bachelor's in Communication in 2017 and has been writing professionally ever since. Read more
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Medically Reviewed By – Dr. Deep Shukla, PhD, MS
Dr. Deep Shukla graduated with a PhD in Neuroscience from Georgia State University in December 2018. Read more

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Medical Disclaimer

The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.