Memory loss and dementia

What is dementia?

Dementia is a syndrome (group of symptoms) of long-term problems with brain functioning, such as thinking, remembering, and reasoning. There are different types of dementia.

Memory loss is the most well-known symptom of dementia, but dementia can affect many other brain functions as well.

Dementia can affect brain functions such as:

• Memory.

• Thinking.

• Language.

• Orientation.

• Judgement.

• Social behaviour.

Dementia isn't the only cause of memory problems. For example, it is normal for memory to deteriorate a little as we get older: this doesn't necessarily mean we are developing dementia. It is normal for memory not to work well when we are distracted or concentrating on too many things at the same time. That's why memory lapses are more common if we are stressed. Physical and mental illness can all temporarily affect memory too.

What are the types of dementia?

There are many different types of dementia. They have different causes, and the symptoms can differ between types of dementia.

The most common types of dementia are:

Alzheimer's disease

This is the most common cause of dementia in older people. The cause of Alzheimer's disease is not fully understood, but it is thought that abnormal proteins, called plaques and tangles, build up in the brain and stop it from working properly.

Vascular dementia

This is the second-most common cause of dementia in older people. Vascular dementia is caused by reduced blood flow to the brain, which damages brain cells. This can happen for a variety of reasons. One type of vascular dementia, called subcortical vascular dementia, occurs due to damage to small blood vessels supplying the brain. Another type, multi-infarct dementia, occurs as a result of several different small strokes affecting different areas of the brain.

Mixed dementia

This is a combination of two or more types of dementia; for example, if someone has both Alzheimer's disease and vascular dementia.

Lewy body dementia

This is a type of dementia caused by lumps of protein in the brain, called Lewy bodies. It can cause hallucinations, movement problems, and unpredictable changes in thinking and alertness that can fluctuate from day-to-day.

Frontotemporal dementia

This is a type of dementia that causes the frontal and temporal lobes of the brain to shrink and stop working. It often causes problems with behaviour and language.

Other types of dementia

There are many other types of dementia, such as:

• Dementia due to Parkinson's disease.

• Dementia due to Huntington's disease.

• Normal pressure hydrocephalus.

• Creutzfeldt-Jakob disease.

• Dementia due to HIV infection.

• Dementia due to excessive alcohol use.

• Wernicke-Korsakoff syndrome (which can be linked to heavy alcohol use).

What are the symptoms of dementia?

All types of dementia cause problems with functioning of the brain. The exact symptoms can differ for different types of dementia.

In general, dementia tends to cause the following symptoms:

Loss of mental ability

Memory problems

Memory problems are often the most noticeable sign of dementia. Forgetting recent events is common, like going to the store and not remembering what was needed or misplacing things.

People with dementia may remember their childhood or past events well until the condition becomes severe. As it worsens, they might struggle to recall recent events, feel like they’re living in the past, or not recognize their true age. They may forget simple facts (like the name of the Prime Minister), have trouble remembering names, or finding the right words, often repeating questions.

Language problems

Language issues can also develop. For example, someone with dementia may have difficulty understanding what is said to them or understanding written information. Problems with attention and concentration can also occur. It is common for someone with dementia not to be able to settle to anything and this can make them appear restless.

Disorientation

New surroundings and new people may confuse a person with dementia: they can become easily disorientated. However, in familiar places, and with old routines, they may function well. This is why some people with mild dementia cope well in their own homes. Losing track of time is also a common problem in someone with dementia. For example, not knowing if it is morning or afternoon, or what day it is. A person with dementia may get lost easily.

Learning new skills

People who develop dementia may find it difficult to grasp new ideas or learn new skills. For example, how to use a new household gadget. The ability to think, calculate and problem-solve can be affected as intellect begins to fail. Difficulties with planning and decision making can develop.

Changes in mood, behaviour and personality

At first, someone with dementia may appear to be easily irritated or moody. It is often family or friends who notice this. Some people with early dementia recognise that they are failing and become depressed. However, many people with dementia are not aware that they have it. They may remain cheerful. The distress is often felt more by relatives who may find it difficult to cope.

More challenging behaviour may develop in some people over time. For example, in some cases, a person with dementia may become quite disinhibited. This means that he or she may say or do things quite out of character. This is often difficult for families and friends to cope with. Some people with dementia can also become agitated or even aggressive and this may be directed towards their carers. They may become suspicious or fearful of others. In some people, delusions (abnormal beliefs) and hallucinations (a false perception of something that is not really there) can occur. Visual hallucinations can be a common problem in dementia with Lewy bodies (DLB).

Mood, behavioural and personality changes may mean that someone with dementia is not able to interact with others in a social situation and they can become quite withdrawn. Sleep is often affected and pacing and restless wandering can become a problem for some.

Problems carrying out day-to-day activities

Difficulty with self-care usually develops over time. For example, without help, some people with dementia may not pay much attention to personal hygiene. They may forget to wash or change their clothes. Remembering to take medication can become an issue. The person may also have difficulty keeping up their home. Shopping, cooking and eating may become difficult. This can lead to weight loss. Driving may be dangerous and not possible for someone with dementia.

Later-stage symptoms of dementia

As dementia progresses, it can cause more significant problems, such as:

• Not recognising close family or friends.

• Having difficulty swallowing food or drink.

• Losing the ability to speak altogether.

• Developing bladder and bowel incontinence.

• Mobility problems, such as being unable to walk unaided, needing a wheelchair to get around, or being completely unable to get out of bed.

• Losing weight and losing appetite.

What causes dementia?

In general, dementia is caused by things that damage brain cells and the connections between them.

The different types of dementia have different causes. For example, although we don't fully understand why it happens, Alzheimer's disease seems to be caused by the buildup of abnormal proteins in the brain.

You can find out more about the causes of dementia in the separate leaflet called Causes of memory loss and dementia.

How common is dementia?

The World Health Organization (WHO) tells us there are about 50 million people in the world with dementia, and nearly 10 million developing the condition each year. By 2050, it is expected that there will be 135.5 million people in the world with dementia (over 2 million in the UK). So if dementia is affecting you or your loved one, you are certainly not alone.

The likelihood of getting dementia increases with age. Having said that, more than half of people will never develop dementia even if they reach the age of 95.

Patient picks for Memory loss and dementia

Brain and nerves

What is early Alzheimer’s disease - and what causes it?

Around 70,800 people in the UK have early onset dementia - meaning they are diagnosed before the age of 65. Alzheimer's disease, the most common cause of dementia, accounts for around one third of these cases. Here we look at what we know about Alzheimer's - its causes and symptoms.

by Lydia Smith

Brain and nerves

Causes of memory loss and dementia

Everybody forgets things from time to time. In general, the things that you tend to forget most easily are the things that you feel do not matter as much.

by Dr Colin Tidy, MRCGP

What are the stages of dementia?

Typically, symptoms of dementia tend to develop slowly, often over several years. In the early stages of the disease, many people with mild dementia cope with just a small amount of support and care. As the disease progresses more care is usually needed.

In the later stages of dementia, speech may be lost and severe physical problems may develop, including problems with mobility, incontinence and general frailty. This can make people more susceptible to other health problems such as infections. Often, people with dementia die from another health problem such as a severe chest infection. So, the dementia isn't the cause of their death but has contributed to it.

Some people can live for many years after dementia has been diagnosed. However, the condition does shorten lifespan. On average, once diagnosed with dementia, people are:

• In the mild early stage for one or two years.

• In the moderate stage, needing help looking after themselves for another two or three years.

• In a severe stage by four to five years after diagnosis, being completely dependent on carers and more or less completely inactive.

The average survival after diagnosis is 3-9 years, but people can survive for up to 20 years after being diagnosed with dementia.

How is dementia diagnosed?

Dementia is difficult to diagnose in some people. In the beginning, symptoms are often put down to other causes. There may also be a degree of protection by friends, carers and relatives who help the person to look after themself and, by doing so, cover up the person's difficulties.

However, it is often not the person with the symptoms but rather their relatives, carers or friends who have concerns that the person may have dementia. They may be concerned about the person's memory or behaviour. However, people with a high intellect or a demanding job may notice themselves that their mental ability is starting to fail.

Visit your doctor

The first step if you are concerned that you may be developing dementia is to see your doctor. Or, if you are worried that someone close to you may have dementia, you should encourage them to consult their doctor. They may agree for you to see their doctor with them.

Your doctor may suggest some special tests to look at your memory and mental ability, to see whether dementia is likely or not. This does not take long and is usually a series of questions or other exercises that your doctor asks you to complete.

Your doctor may also suggest some routine tests to make sure that there are no other obvious causes for your symptoms. For example, blood tests to look for infection, vitamin deficiencies, an underactive thyroid gland, etc. If infection is suspected, they may suggest a urine test, a chest X-ray or other investigations. They may also ask questions to make sure that your symptoms are not due to, for example, depression, any medicines that you may be taking, or excess alcohol intake.

Referral to a specialist

Referral for the opinion of a specialist is usually needed to confirm the diagnosis of dementia. This is usually to one of the following:

• A specialist memory clinic.

• A psychiatrist specialised in looking after older people.

• A specialist in the care of elderly people.

• A neurologist.

The specialist may be able to determine the likely cause of dementia and decide if any specific treatment may be helpful (see below). To help with this, they may suggest further investigations such as a magnetic resonance imaging (MRI) scan of the brain.

Other more sophisticated tests may be done if an unusual cause of dementia is suspected.

Usually referral is made to a specialist team as early as possible. This is partly so the person developing dementia and their carers can obtain advice about advance planning. In the earlier stages, people are better able to make decisions about how they wish to be cared for. They are also better able to decide who they want to manage their affairs once they become unable to do so themselves.

Special memory clinics give lots of information on dementia and how to manage it. Sometimes before dementia is established, there is an earlier phase called mild cognitive impairment. People with mild memory symptoms are often referred to the specialist clinics, so that they can have information early. This is in case their symptoms get worse and develop into dementia.

You can find out more about treatments and support available in the separate leaflet called Medication and treatment for dementia.

Dementia research

Research is underway to try to find ways of diagnosing dementia earlier and more easily, as well as to try to predict who may develop it. Researchers have been looking at proteins (biomarkers) in the blood or the fluid that bathes the brain (the cerebrospinal fluid) in people who have Alzheimer's disease or may go on to develop Alzheimer's disease. Further work is needed before any of this can be used to predict Alzheimer's disease.

Can dementia be treated?

Dementia cannot be cured, but some treatments can help to control the symptoms, depending on the type of dementia.

These include drug and non-drug treatments.

For example:

• Cognitive stimulation therapy can help the memory and thinking skills of people with mild or moderate dementia.

• Talking therapies can help with depression or anxiety.

• Practical aids, equipment, and adaptations, such as:

  • Diaries and calendars to keep track of events.

  • Larger-face clocks with the time and dates.

  • Dossette boxes, or other aids to help people remember when to take their medication.

  • Equipment to help with activities of daily living, such as moving around the house or washing and dressing.

• Medications such as donepezil, rivastigmine, galantamine and memantine, which can help memory loss and confusion in some types of dementia.

• Antipsychotic medications such as haloperidol and risperidoneare sometimes used to help severe agitation, aggression, or distress in people with dementia. But they are usually only used if other, non-drug, measures haven't worked, as they can have serious side-effects.

New treatments are under research.

Recently, drugs such as aducanumab, lecanemab, and donanemab have been developed, which aim to tackle the causes of Alzheimer's disease rather than just manage the symptoms. These might slow down the rate at which Alzheimer's disease progresses.

However, these drugs are expensive, and there is some uncertainty as to how well they actually work. At present, they are not available on the NHS.

Can dementia be prevented?

Some things do show some promise.

Having risk factors for cardiovascular disease can increase your risk of developing all types of dementia. These risk factors include:

• Smoking.

• Raised cholesterol levels.

• Drinking too much alcohol.

• Not doing enough physical activity.

• Being overweight.

• Having diabetes or high blood pressure.

Therefore, it would seem likely that doing something to modify these risk factors may reduce your risk of developing dementia. Stopping smoking, reducing excessive alcohol, and losing weight if you are overweight, for example, may all help to reduce your risk of dementia. Regular physical exercise is advised for all sorts of health benefits, including reducing the risk of dementia. One UK study suggested that a fifth of cases of Alzheimer's disease might have been related to lack of physical activity. It proposed that regular exercise might have actually prevented some of these cases.

Keeping your brain active may also help to reduce your risk of developing dementia. So, for example, consider reading books, doing puzzles, learning a foreign language, playing a musical instrument, taking up a new hobby, etc.

Many studies are going on to look into treatments which may help to prevent dementia. These include certain blood pressure medicines, omega-3 fatty acids, and brain training exercises, as well as the strategies discussed above. However, there is not yet convincing evidence available for any of these.

Further research is ongoing to try to find other ways of preventing dementia.

Living with dementia

Can I keep driving if I have been diagnosed with dementia?

If you have been diagnosed with dementia in the UK, you must notify the DVLA.

Whether or not someone with dementia can drive depends on the severity of their symptoms. Usually in the early stages of dementia it is safe to drive. In later stages it is likely that the ability to drive safely will be impaired.

You may be able to continue driving a car or a motorcycle safely for some time, but you may be asked to have a driving test and/or your doctor may be asked to complete a medical report for the DVLA. Driving will then be subject to a medical assessment and will be reviewed each year.

Someone who has been diagnosed with dementia will not be able to continue to drive a bus (or other vehicle that carries passengers) or a lorry or large goods vehicle.

Sometimes a person with dementia does not have insight into their driving and does not want to notify the DVLA. Friends and relatives can also report their concerns to the DVLA, if so.

What is the life expectancy of someone with dementia?

Life expectancy varies a lot depending on the type of dementia, the age of the person with dementia, the presence of any other medical conditions they have, and also where in the course of the illness the dementia diagnosis was made.

In general, though, dementia does reduce life expectancy compared to people without dementia.

The following is a general guide, based on averages. Some people live for longer. The average life expectancy after diagnosis is:

• Alzheimer's disease - around 6 years.

• Vascular dementia - around 4 years. (This is lower than the averages for Alzheimer's disease, because people with vascular dementia are more likely to have other medical conditions that may shorten their lifespan.)

• Mixed dementia - variable, but around 5 years.

• Lewy body dementia - around 4 years.

• People with frontotemporal dementia - around 5 years.