Overview
Dementia is chronic, global, usually irreversible deterioration of cognition. Diagnosis is clinical; laboratory and imaging tests are usually used to identify treatable causes. Treatment is supportive. Cholinesterase inhibitors can sometimes temporarily improve cognitive function.
Memory loss is a common symptom of dementia, but it can have many different causes. Memory loss alone does not necessarily indicate dementia, despite the fact that it is frequently one of the first symptoms of the illness.
Although there are several additional causes of dementia, Alzheimer’s disease is the most frequent one in older persons. Some dementia symptoms could be reversible, depending on the underlying cause.
Dementia may occur at any age but affects primarily older people. It accounts for more than half of nursing home admissions.
Dementias can be classified in several ways; one way is

- Alzheimer or non-Alzheimer type
- Cortical or subcortical
- Irreversible or potentially reversible
- Common or rare
Dementia should not be confused with delirium, although cognition is disordered in both. The following helps distinguish them:
- Dementia affects mainly memory, is typically caused by anatomic changes in the brain, has slower onset, and is generally irreversible.
- Delirium affects mainly attention, is typically caused by acute illness or drug toxicity (sometimes life threatening), and is often reversible.
Classification of Some Dementias
Classification | Examples |
---|---|
Beta-amyloid deposits and neurofibrillary tangles | Alzheimer disease |
Tau abnormalities | Chronic traumatic encephalopathyCorticobasal ganglionic degenerationFrontotemporal dementia (including Pick disease)Progressive supranuclear palsy |
Alpha-synuclein abnormalities | Dementia with Lewy bodiesParkinson disease dementia |
Autoimmune disorders | Autoimmune dementia, including postencephalitis syndromes |
Huntingtin gene mutation | Huntington disease |
Cerebrovascular disease | Vascular dementias:Binswanger diseaseLacunar diseaseMulti-infarct dementiaStrategic single-infarct dementiaCerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) |
Symptoms
Cognitive changes
- Memory loss, which is usually noticed by someone else
- Difficulty communicating or finding words
- Difficulty with visual and spatial abilities, such as getting lost while driving
- Difficulty reasoning or problem-solving
- Difficulty handling complex tasks
- Difficulty with planning and organizing
- Difficulty with coordination and motor functions
- Confusion and disorientation
Psychological changes
- Personality changes
- Depression
- Anxiety
- Inappropriate behavior
- Paranoia
- Agitation
- Hallucinations
Causes
Dementia is caused by damage to or loss of nerve cells and their connections in the brain. Dementia can affect people differently and result in various symptoms depending on the part of the brain that is affected.
Commonalities among dementias, such as the protein or proteins deposited in the brain or the area of the brain affected, are frequently used to categorize them. Certain illnesses, such those brought on by drug interactions or vitamin shortages, have the appearance of dementias and may respond favorably to therapy.
Progressive dementias
Types of dementias that progress and aren’t reversible include:
- Alzheimer’s disease. The most typical dementia-causing factor is this. Although there are a few unknown causes of Alzheimer’s disease, three genes that can be passed down from parent to kid have a small number of recognized causes. While many genes are likely implicated in Alzheimer’s disease, apolipoprotein E4 is a significant gene that raises risk (APOE). Patients with Alzheimer’s disease have tangles and plaques in their brains. Beta-amyloid protein forms aggregates known as plaques, and tau protein forms fibrous tangles known as tangles. These aggregates may harm healthy neurons and the fibers that link them..
- Vascular dementia. Damage to the blood arteries that feed your brain with oxygen causes this particular form of dementia. Blood vessel issues can result in strokes or have other negative effects on the brain, such as destroying the white matter fibers. Problem-solving challenges, sluggish thinking, and loss of focus and organization are some of the most typical symptoms of vascular dementia. They are typically more obvious than memory loss.
- Lewy body dementia. Lewy bodies, which resemble aberrant protein balloons, have been discovered in the brains of persons with Parkinson’s disease, Alzheimer’s disease, and Lewy body dementia. One of the more prevalent varieties of progressive dementia is this one. Typical warning signs and symptoms include acting out nightmares while sleeping, seeing things that aren’t there, and having trouble focusing and paying attention. Tremors, stiffness, and sluggish or uncoordinated movement are other symptoms (parkinsonism).
- Frontotemporal dementia. The frontal and temporal lobes of the brain’s nerve cells and their connections break down in a variety of disorders. These are the areas that are typically linked to language, behavior, and personality. Common symptoms have an impact on speech and movement as well as behavior, personality, thinking, and judgment.
- Mixed dementia. Alzheimer’s disease, vascular dementia, and Lewy body dementia are just a few of the causes of dementia in the brains of adults 80 and older who underwent autopsy research. The effects of mixed dementia on symptoms and therapies are still being researched.
Other disorders linked to dementia
- Huntington’s disease. Caused by a genetic mutation, this disease causes certain nerve cells in your brain and spinal cord to waste away. Signs and symptoms, including a severe decline in thinking (cognitive) skills, usually appear around age 30 or 40.
- Traumatic brain injury (TBI). This condition is most often caused by repetitive head trauma. Boxers, football players or soldiers might develop TBI.Depending on the part of the brain that’s injured, this condition can cause dementia signs and symptoms such as depression, explosiveness, memory loss and impaired speech. TBI may also cause parkinsonism. Symptoms might not appear until years after the trauma.
- Creutzfeldt-Jakob disease. This rare brain disorder usually occurs in people without known risk factors. This condition might be due to deposits of infectious proteins called prions. Signs and symptoms of this fatal condition usually appear after age 60.Creutzfeldt-Jakob disease usually has no known cause but can be inherited. It may also be caused by exposure to diseased brain or nervous system tissue, such as from a cornea transplant.
- Parkinson’s disease. Many people with Parkinson’s disease eventually develop dementia symptoms (Parkinson’s disease dementia).
Dementia-like conditions that can be reversed
Some causes of dementia or dementia-like symptoms can be reversed with treatment. They include:
- Infections and immune disorders. Dementia-like symptoms can result from fever or other side effects of your body’s attempt to fight off an infection. Multiple sclerosis and other conditions caused by the body’s immune system attacking nerve cells also can cause dementia.
- Metabolic problems and endocrine abnormalities. People with thyroid problems, low blood sugar (hypoglycemia), too little or too much sodium or calcium, or problems absorbing vitamin B-12 can develop dementia-like symptoms or other personality changes.
- Nutritional deficiencies. Not drinking enough liquids (dehydration); not getting enough thiamin (vitamin B-1), which is common in people with chronic alcoholism; and not getting enough vitamins B-6 and B-12 in your diet can cause dementia-like symptoms. Copper and vitamin E deficiencies also can cause dementia symptoms.
- Medication side effects. Side effects of medications, a reaction to a medication or an interaction of several medications can cause dementia-like symptoms.
- Subdural hematomas. Bleeding between the surface of the brain and the covering over the brain, which is common in the elderly after a fall, can cause symptoms similar to those of dementia.
- Brain tumors. Rarely, dementia can result from damage caused by a brain tumor.
- Normal-pressure hydrocephalus. This condition, which is caused by enlarged ventricles in the brain, can result in walking problems, urinary difficulty and memory loss.
Risk factors
Many factors can eventually contribute to dementia. Some factors, such as age, can’t be changed. Others can be addressed to reduce your risk.
- Age. The risk rises as you age, especially after age 65. However, dementia isn’t a normal part of aging, and dementia can occur in younger people.
- Family history. Having a family history of dementia puts you at greater risk of developing the condition. However, many people with a family history never develop symptoms, and many people without a family history do. There are tests to determine whether you have certain genetic mutations.
- Down syndrome. By middle age, many people with Down syndrome develop early-onset Alzheimer’s disease.
Diagnosis
Dementia and its form can be difficult to diagnose. The clinician must identify the pattern of skill and function loss and ascertain what the patient is still capable of in order to pinpoint the dementia’s underlying cause. Now, biomarkers have been made accessible to diagnose Alzheimer’s disease more precisely.
Your doctor will examine you physically and go through your medical history and symptoms. He or she will probably also inquire about your symptoms from a trusted source.
Doctors will likely do a series of tests that can assist them identify the issue because there is no one test that can diagnose dementia.
Cognitive and neuropsychological tests
Doctors will evaluate your thinking ability. A number of tests measure thinking skills, such as memory, orientation, reasoning and judgment, language skills, and attention.
Neurological evaluation
Doctors evaluate your memory, language, visual perception, attention, problem-solving, movement, senses, balance, reflexes and other areas.
Brain scans
- CT or MRI. These scans can check for evidence of stroke or bleeding or tumor or hydrocephalus.
- PET scans. These can show patterns of brain activity and whether the amyloid or tau protein, hallmarks of Alzheimer’s disease, have been deposited in the brain.

Laboratory tests
Simple blood tests can detect physical problems that can affect brain function, such as vitamin B-12 deficiency or an underactive thyroid gland. Sometimes the spinal fluid is examined for infection, inflammation or markers of some degenerative diseases.
Psychiatric evaluation
A mental health professional can determine whether depression or another mental health condition is contributing to your symptoms.
Treatment
Medications
The following are used to temporarily improve dementia symptoms.
- Cholinesterase inhibitors. These drugs, which include galantamine (Razadyne), rivastigmine (Exelon), and donepezil (Aricept), increase levels of a chemical messenger that is involved in memory and judgment. These drugs may be recommended for different dementias, such as vascular dementia, Parkinson’s disease dementia, and Lewy body dementia, even though their primary usage is to treat Alzheimer’s disease. Diarrhoea, vomiting, and nausea are possible side effects. Sleep difficulties, fainting, and a decreased heart rate are some more potential side effects.
- Memantine. Memantine (Namenda) functions by controlling the action of glutamate, a different chemical messenger important in mental processes including memory and learning. Memantine may occasionally be administered along with a cholinesterase inhibitor. Dizziness is a frequent adverse effect of memantine.
- Other medications. In order to treat other signs or conditions like agitation, hallucinations, parkinsonism, depression, or sleep issues, your doctor may prescribe medication.

Acuranumab (Aduhelm) was authorized by the Food and Drug Administration (FDA) in 2021 for the treatment of certain Alzheimer’s cases. The medication was tested on persons with early-stage Alzheimer’s disease, including those who had the illness-related mild cognitive impairment.
Because it dissolves amyloid plaques from the brain, the medication has been licensed in the US. However because there are conflicting results and little publicity, it hasn’t been widely utilized to delay cognitive decline.
Lecanemab, a different Alzheimer’s drug, has demonstrated potential in treating mild Alzheimer’s disease and moderate cognitive impairment brought on by Alzheimer’s disease. It might be obtainable in 2023.
According to a phase 3 clinical trial, the drug significantly reduced the rate of cognitive loss in individuals with early Alzheimer’s disease (27%). Lecanemab functions by inhibiting the aggregation of amyloid plaques in the brain. The greatest trial to date examined whether removing amyloid plaque clusters from the brain could delay the onset of the condition.
The FDA is investigating lecanemab. Another study examines the medication’s potential efficacy for those at risk of developing the disease, such as those who have a first-degree family (a parent or sibling) who has the condition.
Helping someone with dementia
You can help a person cope with the disease by listening, reassuring the person that he or she still can enjoy life, being supportive and positive, and doing your best to help the person retain dignity and self-respect.
Therapies
Several dementia symptoms and behavior problems might be treated initially using nondrug approaches, such as:
- Occupational therapy. An occupational therapist can show you how to make your home safer and teach coping behaviors. The purpose is to prevent accidents, such as falls; manage behavior and prepare you for the dementia progression.
- Modifying the environment. Reducing clutter and noise can make it easier for someone with dementia to focus and function. You might need to hide objects that can threaten safety, such as knives and car keys. Monitoring systems can alert you if the person with dementia wanders.
- Simplifying tasks. Break tasks into easier steps and focus on success, not failure. Structure and routine also help reduce confusion in people with dementia.
Lifestyle and home remedies
Dementia symptoms and behavior problems will progress over time. Caregivers and care partners might try the following suggestions:
- Enhance communication. When talking with your loved one, maintain eye contact. Speak slowly in simple sentences, and don’t rush the response. Present one idea or instruction at a time. Use gestures and cues, such as pointing to objects.
- Encourage exercise. The main benefits of exercise in people with dementia include improved strength, balance and cardiovascular health. Exercise might also help with symptoms such as restlessness. There is growing evidence that exercise also protects the brain from dementia, especially when combined with a healthy diet and treatment for risk factors for cardiovascular disease.Some research also shows that physical activity might slow the progression of impaired thinking in people with Alzheimer’s disease, and it can lessen symptoms of depression.
- Engage in activity. Plan activities the person with dementia enjoys and can do. Dancing, painting, gardening, cooking, singing and other activities can be fun, can help you connect with your loved one, and can help your loved one focus on what he or she can still do.
- 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 in the bedroom, hall and bathroom to prevent disorientation.Limiting caffeine, discouraging napping and offering opportunities for exercise during the day might ease nighttime restlessness.
- Keep a calendar. A calendar might help your loved one remember upcoming events, daily activities and medication schedules. Consider sharing a calendar with your loved one.
- Plan for the future. Develop a plan with your loved one while he or she is able to participate that identifies goals for future care. Support groups, legal advisers, family members and others might be able to help.You’ll need to consider financial and legal issues, safety and daily living concerns, and long-term care options.
Other therapies
The following techniques may help reduce agitation and promote relaxation in people with dementia.
- Music therapy, which involves listening to soothing music
- Light exercise
- Watching videos of family members
- Pet therapy, which involves use of animals, such as visits from dogs, to promote improved moods and behaviors in people with dementia
- Aromatherapy, which uses fragrant plant oils
- Massage therapy
- Art therapy, which involves creating art, focusing on the process rather than the outcome

Prevention
There’s no sure way to prevent dementia, but there are steps you can take that might help. More research is needed, but it might be beneficial to do the following:
- Keep your mind active. Mentally stimulating activities, such as reading, solving puzzles and playing word games, and memory training might delay the onset of dementia and decrease its effects.
- Be physically and socially active. Physical activity and social interaction might delay the onset of dementia and reduce its symptoms. Aim for 150 minutes of exercise a week.
- Quit smoking. Some studies have shown that smoking in middle age and beyond might increase your risk of dementia and blood vessel conditions. Quitting smoking might reduce your risk and will improve your health.
- Get enough vitamins. Some research suggests that people with low levels of vitamin D in their blood are more likely to develop Alzheimer’s disease and other forms of dementia. You can get vitamin D through certain foods, supplements and sun exposure.More study is needed before an increase in vitamin D intake is recommended for preventing dementia, but it’s a good idea to make sure you get adequate vitamin D. Taking a daily B-complex vitamin and vitamin C also might help.
- Manage cardiovascular risk factors. Treat high blood pressure, high cholesterol and diabetes. Lose weight if you’re overweight.High blood pressure might lead to a higher risk of some types of dementia. More research is needed to determine whether treating high blood pressure may reduce the risk of dementia.
- Treat health conditions. See your doctor for treatment for depression or anxiety.
- Maintain a healthy diet. A diet such as the Mediterranean diet — rich in fruits, vegetables, whole grains and omega-3 fatty acids, which are commonly found in certain fish and nuts — might promote health and lower your risk of developing dementia. This type of diet also improves cardiovascular health, which may help lower dementia risk.
- Get good-quality sleep. Practice good sleep hygiene, and talk to your doctor if you snore loudly or have periods where you stop breathing or gasp during sleep.
- Treat hearing problems. People with hearing loss have a greater chance of developing cognitive decline. Early treatment of hearing loss, such as use of hearing aids, might help decrease the risk.