Overview: Alzheimer's disease
Alzheimer's disease is the most common cause of dementia. The disease takes its name from the psychiatrist Alois Alzheimer, who in the early twentieth century was the first person to describe the disease. Over time, people who have Alzheimer’s lose their memory and ability to concentrate. Spatial and temporal orientation become more difficult, and it is also harder for them to manage on their own in everyday life. People who have Alzheimer’s disease will need more support as the disease progresses.
- Risk factors
- Frequency of occurrence
- Course of the disease
- Everyday life
- Further information
There are other possible causes of dementia besides Alzheimer’s disease. These include problems with the flow of blood in the brain (vascular dementia). Some people, mainly older people, have a combined form of Alzheimer’s and vascular dementia. Parkinson’s disease, brain injury or tumors can also cause dementia. Long-term alcohol consumption may lead to dementia too.
There are similarities, but also differences, between the different forms of dementia: the symptoms, the course the disease takes, and the treatment options can all vary. This overview is only about Alzheimer’s.
Most people mainly associate Alzheimer’s disease with forgetfulness. But it can have many different symptoms and develops differently in each individual person. It is not only changes affecting the brain that influence how someone reacts to having Alzheimer’s and copes with the disease. This will also depend on that individual’s personality, life experiences, and current circumstances and relationships with other people.
Memory and mental ability
Most people’s memory and other mental abilities gradually get worse as they get older. It is a natural part of aging to no longer be able to react as quickly and flexibly to new situations as we used to. It is often not as easy to recognize problems in new areas and to solve them. But it is still possible to access the knowledge that has been gained over the years, and retain orientation and good judgement.
Reduced mental performance that is due solely to aging will not affect your independence. That is different for people who have Alzheimer’s disease. Their memory gradually fades away. At first, short-term memory is affected more. This means that they forget about events that have just happened, but can still remember experiences from long ago. But long-term memory also fades with time. Concentration also declines, making it more and more difficult to maintain orientation in time and space.
It becomes more difficult to link things that were learned in the past to new situations or impressions. There comes a point when it is no longer possible to understand contexts or assess information, formulate an opinion and then decide what to do. One example: A person who has late-stage Alzheimer’s can see that it is raining outside, and can express this fact in words. But he will not be able to draw conclusions for his own actions. He may then go out to do his shopping in an undershirt instead of putting on a raincoat or taking an umbrella.
Activities that are made up of several steps (like shopping or cooking) become more and more difficult as someone’s memory, comprehension and planning skills start to fade. In early-stage Alzheimer’s, completing more complex business matters can be a problem: doing taxes may become an impossible task. Forgetfulness might not only mean forgetting what you wanted to buy or why you left the house, but can also make you more likely to get lost and have problems finding your way home again.
Speech and language
Everyone has had to search around for the right word or felt tongue-tied now and then. But forgetting individual words more and more frequently is a different matter. As dementia progresses, it becomes more difficult to remember the right words. People with dementia may use words or phrases that do not match the context instead, and this makes it difficult to understand them. And people with dementia also forget the meaning of words and are then often no longer able to follow the person they are talking to. This makes it more and more difficult to communicate verbally.
Mental health and changes in behavior
Many people with Alzheimer’s will go through noticeable changes in their behavior. Later on their personality may also change considerably. They can become unusually fearful, distrustful or passive, or may become aggressive as well. These changes can happen suddenly, and might cause rage attacks – or they may develop gradually, as with listlessness. Abnormal behavior like this may be related to the disease. But fear, passivity or aggression can sometimes be perfectly normal reactions to the circumstances of living with the disease: after all, a person who has Alzheimer’s keeps finding themselves in situations that are confusing and in which they behave “wrongly.”
Plus there is the shame and frustration of forgetting more and more, being wrong a lot of the time, and gradually losing your independence. Many people who have Alzheimer’s feel that others are patronizing them, and are worried about being seen only as a sick and needy person. Some people with Alzheimer’s have depression and trouble sleeping too. Sometimes, they might also experience unusually euphoric phases.
In Alzheimer’s disease, more and more brain cells are lost as time goes by. It is not clear why this happens. One thing that is known is that people with Alzheimer’s do not have enough of an important chemical messenger called acetylcholine in their brain. And it has also been shown that small protein particles (for example plaques) build up in their brain. These might cause the nerve cells to die. But it is still not known what actually causes Alzheimer’s disease. Several factors probably play a role.
The risk of developing Alzheimer’s increases with age, starting at about 65. Many studies have looked at whether particular life circumstances, diseases or behaviors can increase or lower the risk of Alzheimer’s. The research has not yet produced any clear answers, but it does suggest that these factors may play a role:
- high cholesterol level
- little social contact
Preventative factors include:
- good education
- mental and physical activity
- good social network
- balanced diet including a lot of fruit and vegetables, legumes and nuts, olive oil and whole grains, more fish than meat and moderate alcohol consumption
Research has shown that some people are more likely to develop Alzheimer’s than others. But just because there is a relationship between two things, it does not mean that one of them is causing the other. For example, if dementia is known to be more common in people who have a lower level of education, their level of education is not necessarily the cause of their dementia. People who have a lower level of education might also live in less healthy environments – and that might be what increases their risk of Alzheimer’s disease. The role of different circumstances and behaviors in the development of Alzheimer’s needs to be studied more closely.
Not many genes are known to influence whether someone gets Alzheimer’s. In some families, some members already develop the disease in middle age. Genetic tests can be used to find out whether they have what is called pre-senile Alzheimer’s. If they do, it is very likely that siblings and children will also develop it.
There are other genetic factors that are often identified as being linked to Alzheimer’s, but they do not make it possible to predict who will develop the disease and who will not. One example is special types of a specific gene called the APOE gene, which plays a role in breaking down cholesterol. Testing for this particular gene would not be much help since many of the people who have one of these types do not end up developing Alzheimer’s. So getting tested might give someone a scare for no good reason.
Genetic tests can often be misleading and have serious consequences for those involved, so they should only be done at human genetics institutes and with carefully prepared information and consultation.
Frequency of occurrence
In Germany there are about 1.4 million people who have dementia. Most of them are women, which is mostly due to the fact that women tend to live longer than men. Dementia is mostly diagnosed in older people: about 2% of 65 to 69-year-olds will develop it, compared to about 10% of all 80 to 84-year-olds. It is estimated that around 70% of people who have dementia have Alzheimer’s.
Course of the disease
Alzheimer’s is a chronic disease that progresses over the course of many years. It typically begins after the age of 65. Alzheimer’s that starts before beforehand will usually progress faster than if had developed later on.
Alzheimer’s disease has three stages, and each has its characteristic symptoms. But how fast these changes happen can vary from person to person. Some symptoms may appear earlier, and others may not show up at all:
In early-stage (mild) Alzheimer’s, people have a bit more trouble managing their lives on their own, but living independently is usually still possible. It is often difficult to tell the difference between early-stage symptoms and simple age-related forgetfulness, as they can be quite similar. But forgetfulness, absentmindedness and lack of concentration mean that more complex everyday tasks are difficult to complete. People who have early-stage Alzheimer’s will almost always need help with business and financial matters or official appointments. Driving and taking medication regularly are two other critical areas.
Behavior and mood can already change in early-stage Alzheimer’s. The limitations resulting from the disease can cause fear, stress, anger, or even feelings of shame: it can be embarrassing to forget things and lose your orientation. And it takes a lot of strength to find strategies for dealing with these problems. A person’s inner drive and interest in hobbies or other activities may fade. Some people feel down or irritable, or they may have intense mood swings. These mood swings – for example suddenly bursting into tears for no apparent reason – are often puzzling as well as draining for other family members.
People with middle-stage (moderate) Alzheimer’s usually have to give up living independently. They can still eat, drink and wash themselves, and perhaps do simple tasks around the home or garden, but may have to be reminded and asked to do so. Cooking, shopping, keeping their home clean, and going out on a walk are only possible with the help of others.
They are more likely to get lost, not find their way back home, burn something on the stove and endanger themselves or others. Patterns of behavior such as frantic pacing, seemingly meaningless rummaging through drawers and fiddling with clothing become more frequent. Outbursts of rage, distrust and aggressive behavior are also consequences of problems associated with Alzheimer’s that affect perception and limit a person’s abilities. People’s daily sleep-wake cycle is often affected. It becomes more difficult for them to express things in words and understand what other people say. They also confuse the past with the present. For instance, they may falsely believe that their parents are still alive and are expecting them to come back home.
In late-stage (severe) Alzheimer’s, people affected by the disease will need constant help from others. Speech and language problems may start making conversation barely possible. Help is now even needed to accomplish simple everyday activities, and to eat and drink. People who have late-stage Alzheimer’s are often restless, hallucinate or confuse the past with the present. They no longer recognize people who they used to know very well. The control of bodily functions and the ability to coordinate movement may also be lost.
On average, people with Alzheimer’s die about six years after being diagnosed. But many people also live with the disease a good deal longer.
It is not yet possible to diagnose Alzheimer’s with complete certainty using the currently available tests while the person is still alive. The disease is diagnosed if someone has the typical symptoms and no other cause can be found. Looking at the brain usingImaging techniques like computed tomography (CT) or magnetic resonance imaging (MRI) is not enough to tell if someone has Alzheimer’s disease or not.
Because symptoms like forgetfulness, changes in behavior and problems with orientation can have many different causes, it is important not to rush to a diagnosis of Alzheimer’s. These symptoms might also be caused by depression or other physical problems like meningitis, a stroke or bleeding in the brain. A fluid or vitamin deficiency or side effects of medication can sometimes also cause symptoms like these. There are often good treatments for these things and the symptoms will then improve or disappear completely. Alzheimer’s is diagnosed only if symptoms have lasted for more than six months and any other causes are considered to be unlikely.
This means that comprehensive diagnostic tests are necessary. People generally go to their family doctor first. If it is thought that someone might have Alzheimer’s, specialists (neurologists, psychiatrists, radiologists) often work together. It can be helpful to have an appointment at hospital that specializes in memory problems, particularly when the disease is still in the early stages.
Talk with the doctor
The doctor will first ask about the person’s symptoms, problems in everyday life, and general life situation. They will also be asked about their mental state, for example about whether they experience mood swings or whether their emotional state has changed. Medication use, lifestyle, and physical and mental illnesses will also be discussed. It can be helpful to have someone close to the person being diagnosed to come along to the talk for support. Relatives or friends often notice changes in behavior that the person affected by the disease does not even notice. Or the person may be too ashamed or embarrassed to talk about these things.
Certain tests are done to get an idea of how far the disease has advanced and how it might progress. There are short tests where a trained specialist asks questions and has the person do short tasks testing memory, judgment, speech and concentration. These tests usually last about 15 minutes. Some of the commonly used tests include the mini-mental state examination (MMSE), the clock-drawing test and the dementia detection test (DemTecT). These tests can give an indication of how limiting the disease has become. But neuropsychological testing, which is more extensive, is often needed to get a more exact diagnosis.
There are number of tests that can help show whether other diseases or conditions are possibly causing or influencing the symptoms. These include a physical examination, blood tests or imaging techniques like computed tomography or magnetic resonance imaging (MRI). A lumbar puncture may also be done to take a sample of cerebrospinal fluid.
People who have Alzheimer’s, and those close to them, need long-term help and treatment. Depending on their needs, their life situation and the stage of disease, a whole team of people may be involved in providing care. These could include specialists such as doctors, psychologists, nurses and social workers, as well as volunteers. Both treatment with medications and non-drug interventions aim to
- increase quality of life,
- keep the ability to do everyday tasks and stay independent for as long as possible,
- relieve mental health problems, and
- help family members to cope better.
The most common medications used to treat Alzheimer’s disease include cholinesterase inhibitors, memantine und extracts from the leaves of the Ginkgo biloba tree. You can read more about the different drugs in our information “Medications for the treatment of Alzheimer’s disease” and in our research summaries on the effectiveness of cholinesterase inhibitors, Ginkgo and memantine.
Examples of non-drug treatments include memory and orientation training, doing everyday activities as a group, or art therapy, aromatherapy, and animal-assisted or music therapy. Physical activities and massages can help too. Education programs for family members and other non-professional caregivers are also an option. You can read more about this in our information on non-drug interventions for the treatment of Alzheimer’s disease.
Being diagnosed with Alzheimer’s comes as a real shock to many people. It is often a life-changing diagnosis. Sometimes the diagnosis makes it easier to understand previously inexplicable changes in behavior or personality. Every person who develops Alzheimer’s experiences their situation differently, and copes with it differently. Some people are able to accept the disease and to go on living an active and satisfying life for as long as possible despite having Alzheimer’s. Others have a harder time. They may become withdrawn, and are often sad or depressed. Still others will try to ignore the disease and its symptoms.
Especially right after they hear the diagnosis, many people feel torn between the desire for independence and the need for security and support. Most people who have Alzheimer’s disease do realize that they will need help at some point. But only very few will find it easy to accept the gradual loss of their abilities and accept the support they need.
On the one hand, most people who have been diagnosed with Alzheimer’s think it is important to live in the present and to enjoy doing what they can still do. On the other hand, many people are worried about the future and may wonder how to go about planning the rest of their life. There are suddenly new concerns to confront: Am I still able to perform at work, and if so, for how much longer? Who should make my decisions for me when I no longer can? How long will I still be able to drive a car or live on my own? What will I do when I need to be cared for?
Over time many people manage to deal with these kinds of questions and conflicts, and come to accept life with Alzheimer’s. Getting support from others plays a big role here. For many people with Alzheimer’s, their family is their most important source of support. But the disease will also affect relationships with family members and friends. It becomes more difficult to pursue common interests. Many of the roles and responsibilities shared by family members or couples will need to be reorganized. For example, if a woman who has always kept track of the couple’s finances is no longer able to do so, her husband would have to take on this responsibility instead.
Some people say that their family ties became stronger after they were diagnosed with Alzheimer’s. Some couples feel like a team that has to stick together, now more than ever. But there may still be tension and conflicts over the course of the disease. Many family members and family members who care for someone with Alzheimer’s find it hard to cope with, and may need support themselves after a while.
A lot of people with Alzheimer’s disease benefit from dealing openly with their condition and are met with understanding and support. Humor may also be one way to deal with the disease in certain situations. But unpleasant experiences, such as failing at something or getting negative reactions from other people, cannot be avoided.
Sharing experiences with others affected by the disease, for example in a self-help group, is often considered to be helpful. It is important to stay active and keep up your hobbies: singing, hiking, cooking, painting – it is still possible to do many of these activities for a long time despite Alzheimer’s. Activities also help to keep someone’s mind off their disease.
There are many decisions that need to be made over the course of the disease – decisions about everyday practicalities, but also about treatments, planning ahead, care at later stages of the disease, and the most suitable place to live (at home, in a nursing home, group living). Nowadays people who have Alzheimer’s are more and more interested in wanting to be involved in these decisions for as long as they are able to. They want people to talk with them, not just about them.
As this disease progresses, people with Alzheimer’s gradually lose their independence. They not only become dependent on others for care, but also when it comes to making decisions that will affect their life. This can make it even more important to make arrangements for the time when it is no longer possible to make independent decisions. A power of attorney or a living will can be set up to determine who will take over these responsibilities later on, and under which conditions it will take effect. An advance health care directive can also be used to determine whether and which life-sustaining measures should be taken if the person’s condition becomes severe.
Psychological care, nursing care and support for family members who provide care become more and more important as Alzheimer’s progresses. Many cities in Germany offer assistance for people with Alzheimer’s in their everyday activities or for family members, such as services providing daytime care. There are also courses on how to care for people with Alzheimer’s, as well as self-help groups for family members. The main caregiver also has a legal right to request additional care if they get ill themselves or need some time off. Many cities across Germany have care support centers [in German: Pflegestützpunkte] which can be contacted for information on the available services in the local area.
Published by the Institute for Quality and Efficiency in Health Care (IQWiG, Germany)
Next planned update: July 2016. You can find out more about how our health information is updated in our text "Informed Health Online: How our information is produced."
- September 18th 2013 17:26
- July 03rd 2013 15:13
- Show list
IQWiG health information is based on research in the international literature. We identify the most scientifically reliable knowledge currently available, particularly what are known as “systematic reviews.” These summarize and analyze the results of scientific research on the benefits and harms of treatments and other health care interventions. This helps medical professionals and people who are affected by the medical condition to weigh up the pros and cons. You can read more about systematic reviews and why these can provide the most trustworthy evidence about the state of knowledge in our information “Evidence-based medicine.” We also have our health information reviewed to ensure medical and scientific accuracy.
Alzheimer Research Forum (ARF). AlzRisk AD Epidemiology Database. January 28, 2013 [Accessed on: February 6, 2013]. [Full text]
Alzheimer Research Forum (ARF). AlzGene – Field Synopsis of Genetic Association Studies in AD. 18.04.2011 [Accessed on: February 6, 2013]. [Full text]
Ballard C, Gauthier S, Corbett A, Brayne C, Aarsland D, Jones E. Alzheimer's disease. Lancet 2011; 377(9770): 1019-1031. [Summary]
Bunn F, Goodman C, Sworn K, Rait G et al. Psychosocial factors that shape patient and carer experiences of dementia diagnosis and treatment: a systematic review of qualitative studies. PLoS Med 2012; 9(10): e1001331. [Summary]
Burns A, Iliffe S. Alzheimer's disease. BMJ 2009; 338: b158. [Summary]
Butler R, Radhakrishnan. Dementia. Clin Evid (Online). 2012; 09. pii: 1001.
Deutsche Gesellschaft für Allgemeinmedizin und Familienmedizin (DEGAM). Demenz – DEGAM-Leitlinie Nr. 12. Düsseldorf 2008 [Accessed on: February 5, 2013]. [Full text – in German]
Deutsche Gesellschaft für Psychiatrie, Psychotherapie und Nervenheilkunde e.V. (DGPPN) und Deutsche Gesellschaft für Neurologie (DGN). S3-Leitlinie „Demenzen“. November 2009 [Accessed on: February 6, 2013]. [Full text – in German]
Finckh U. Genetische Faktoren bei Alzheimer-Demenz. Deutsches Ärzteblatt 2006; 15: A1010-A1016.
Hirschman KB, Joyce CM, James BD, Xie SX, Karlawish JH. Do Alzheimer's disease patients want to participate in a treatment decision, and would their caregivers let them? Gerontologist 2005; 45(3): 381-388. [Summary]
Moyle W, Kellett U, Ballantyne A, Gracia N. Dementia and loneliness: an Australian perspective. J Clin Nurs 2011; 20(9-10): 1445-1453. [Summary]
Ohman A, Josephsson S, Nygard L. Awareness through interaction in everyday occupations: experiences of people with Alzheimer’s disease. Scand J Occup Ther 2008; 15(1): 43-51. [Summary]
Phinney A, Moody EM. Leisure Connections: Benefits and Challenges of Participating in a Social Recreation Group for People With Early Dementia. Activities, Adaptation & Aging 2011; 35(2): 111-130. [Summary]
Robert Koch-Institut (RKI). Altersdemenz. Berlin: RKI; 2005. (Gesundheitsberichterstattung des Bundes; Volume 28). [Full text – in German]
Stechl E, Lämmler G, Steinhagen-Thiessen E, Flick U. Subjektive Wahrnehmung und Bewältigung der Demenz im Frühstadium – SUWADEM. Z Gerontol Geriat 2007; 40(2): 71-80. [Summary – in German]
Williams JW, Plassman BL, Burke J, Holsinger T, Benjamin S. Preventing Alzheimer's Disease and Cognitive Decline. Evidence Report/Technology Assessment 2010; (193): 1-727. [Full text]
Photo: PantherMedia / Thomas Lammeyer