Dementia is a general term for a decline in mental ability that is severe enough to interfere with daily life. Memory loss is a common example. Alzheimer's disease is the most common type of dementia.

Dementia Overview

Reviewed: May 19, 2014

Dementia is not a specific disease. Instead, it is the name for a group of symptoms caused by disorders that affect the brain and are associated with a decline in memory or other thinking skills that is severe enough to reduce a person's ability to perform everyday activities. People with dementia may not be able to think well enough to do normal activities, such as getting dressed or eating. They may lose their ability to solve problems or control their emotions. Their personalities may change. They may become agitated or see things that are not there.

Memory loss is a common symptom of dementia. However, memory loss by itself does not mean you have dementia. People with dementia have serious problems with 2 or more brain functions, such as memory and language. Although dementia is common in very elderly people, it is not part of normal aging.

Many different diseases can cause dementia, including Alzheimer's disease and stroke. Alzheimer's disease accounts for 60 to 80 percent of cases of dementia. Vascular dementia, which occurs after a stroke, is the second most common type of dementia. Many other conditions can cause symptoms of dementia, including some that are reversible, such as thyroid problems and vitamin deficiencies.

No treatment can cure dementia. However, some drugs may help improve symptoms or slow the decline in mental abilities.

Dementia Symptoms

While symptoms of dementia can vary greatly, at least 2 of the following core mental functions must be significantly impaired to be considered dementia:

  • Memory
  • Communication and language
  • Ability to focus and pay attention
  • Reasoning and judgment
  • Visual perception

People with dementia may have problems with short-term memory, keeping track of a purse or wallet, paying bills, planning and preparing meals, remembering appointments or traveling out of the neighborhood.

Common signs and symptoms of dementia include cognitive changes and psychological changes such as:

  • Memory loss
  • Difficulty communicating or finding words
  • Difficulty with complex tasks
  • Difficulty with planning and organizing
  • Difficulty with coordination and motor functions
  • Problems with disorientation, such as getting lost
  • Personality changes
  • Inability to reason
  • Inappropriate behavior
  • Paranoia
  • Agitation
  • Hallucinations

Many dementias are progressive, meaning symptoms start out slowly and gradually get worse. If you or a loved one is experiencing memory difficulties or other changes in thinking skills, do not ignore them. See a doctor soon to determine the cause. Professional evaluation may detect a treatable condition. And even if symptoms suggest dementia, early diagnosis allows a person to get the maximum benefit from available treatments.

And, it is important to remember that many people have memory loss issues, but this does not mean they have Alzheimer's or another type of dementia.

Dementia Causes

Dementia involves damage of nerve cells in the brain, which may occur in several areas of the brain. This damage interferes with the ability of brain cells to communicate with each other. When brain cells cannot communicate normally, thinking, behavior and feelings can be affected.

Dementia may affect people differently, depending on the area of the brain affected. The brain has many distinct regions, each of which is responsible for different functions (for example, memory, judgment and movement). When cells in a particular region are damaged, that region cannot carry out its functions normally.

Dementias can be classified in a variety of ways and are often grouped by what they have in common, such as what part of the brain is affected, or whether they worsen over time (progressive dementias). Some dementias, such as those caused by a reaction to medications or an infection, are reversible with treatment.

Most changes in the brain that cause dementia are permanent and worsen over time, but thinking and memory problems caused by the following conditions may improve when the condition is treated or addressed:

  • Depression
  • Medication side effects
  • Excess use of alcohol
  • Thyroid problems
  • Vitamin deficiencies

Many factors can eventually lead to dementia. Some factors cannot be changed, but others can be addressed to reduce your risk of developing dementia:

  • Age. The risks of several types of dementia increase after age 65. However, dementia is not a normal part of aging, and dementia can occur in younger people.
  • Family history. A family history of dementia, increases the risk of developing dementia.
  • Down syndrome. By middle age, many people with Down syndrome develop the plaques and tangles in the brain that are associated with Alzheimer's disease. Some may develop dementia.
  • Heavy alcohol use. People who consume large amounts of alcohol may have a higher risk of dementia. Although studies have shown that moderate amounts of alcohol may have a protective effect, abuse of alcohol increases your risk of developing dementia.
  • Atherosclerosis. This buildup of fats and other substances in and on the artery walls (plaques) can reduce the blood flow to the brain and lead to stroke. Reduced blood flow to your brain can also cause vascular dementia.
  • Blood pressure. High or low blood pressure may increase the risk of developing dementia.
  • Cholesterol. High levels of low-density lipoprotein (LDL) cholesterol may increase the risk of developing vascular dementia or Alzheimer's disease.
  • Depression. Although not yet well understood, late-life depression, especially in men, may be related to the development of dementia.
  • Diabetes. Diabetes may increase the risk of developing Alzheimer's disease and vascular dementia.
  • High estrogen levels. Women taking estrogen and progesterone years after menopause may be at greater risk of developing dementia.
  • Homocysteine blood levels. Elevated blood levels of homocysteine, a type of amino acid produced by the body, may increase the risk of developing vascular dementia.
  • Obesity. Being overweight or obese may increase the risk of developing dementia.
  • Smoking. Smoking may increase the risk of developing dementia and blood vessel (vascular) diseases.

Dementia Diagnosis

There is no single test to determine if someone has dementia. Doctors diagnose dementia on the basis of careful medical history, a physical examination, laboratory tests, and the characteristic changes in thinking, day-to-day function and behavior associated with each type. Doctors can determine that a person has dementia with a high level of certainty, but it is harder to determine the exact type of dementia because the symptoms and brain changes of different dementias can overlap.

Doctors may order a number of tests to diagnose dementia and rule out other conditions:

  • Cognitive and neuropsychological tests. In these tests, doctors will evaluate thinking (cognitive) function. A number of tests measure thinking skills such as memory, orientation, reasoning and judgment, language skills, and attention.
  • Neurological evaluation. In a neurological evaluation, doctors will evaluate your movement, senses, balance, reflexes and other areas. Doctors may use the neurological evaluation to diagnose other conditions.
  • Brain scans. Doctors may order brain scans, such as a CT or MRI, to check for evidence of stroke or bleeding and to rule out the possibility of a tumor.
  • Laboratory tests. Simple blood tests can rule out physical problems that can affect brain function, such as vitamin B-12 deficiency or an underactive thyroid gland.
  • Psychiatric evaluation. A mental health specialist (psychologist or psychiatrist) may evaluate whether depression or another psychological condition may be causing symptoms of dementia.

Living With Dementia

People with dementia will experience progression of their symptoms and behavior problems over time. Caregivers can help patients with dementia improve symptoms by modifying day-to-day routines and activities:

  • Enhance communication. When talking with your loved one, maintain eye contact. Speak slowly in simple sentences, and don't rush the response. Present only one idea or instruction at a time. Use gestures and cues, such as pointing to objects.
  • Encourage exercise. Exercise benefits everyone, including people with dementia. The main benefits of exercise include improved strength and cardiovascular health. Some research also shows physical activity may slow the progression of impaired thinking (cognitive) function in people with dementia. Exercise can also lessen symptoms of depression, help retain motor skills and create a calming effect.
  • Encourage participation in games and thinking activities. Participating in games, crossword puzzles and other activities in which people are using thinking (cognitive) skills may help slow mental decline in people with dementia.
  • Establish a nighttime ritual. Behavior is often worse at night. Try to establish going-to-bed rituals that are calming and away from the noise of television, meal cleanup and active family members. Leave night lights on to prevent disorientation. Limiting caffeine during the day, discouraging daytime napping and offering opportunities for exercise during the day may help prevent nighttime restlessness.
  • Encourage keeping a calendar. Keeping a reminder calendar may help your loved one remember upcoming events, daily activities, and medication schedules. Consider sharing a calendar with your loved one.
  • Modify the environment. Reduce clutter and distracting noise can make it easier for someone with dementia to focus and function. It also may reduce confusion and frustration.
  • Modify responses. A caregiver's response to a behavior can make the behavior, such as agitation, worse. Avoid correcting and quizzing a person with dementia. Reassure the person and validate his or her concerns.
  • Modifying tasks. Break tasks into easier steps and focus on success, not failure. Structure and routine during the day also help reduce confusion in people with dementia.
  • Plan for the future. Develop a plan with your loved one that identifies goals for care in the future. Several support groups, legal advisers, family members and others can help you. Consider financial and legal issues, safety and daily living concerns, and long-term care options.

Dementia Treatments

Most types of dementia cannot be cured. However, treatment of dementia symptoms may help slow or minimize the development or progression of symptoms.

Several medications are available to treat symptoms of dementia including:

These drugs regulate the chemicals that transmit messages between neurons and they help maintain thinking, memory, and communication skills.

Dementia Prognosis