Dementia
Last update: March 2024
Contact: Aurélie Halsband
Dementia is a clinical term used to describe a decline in the memory, thinking and verbal abilities of those affected, which in the vast majority of cases is an irreversible process. It is almost always the result of an organic brain disorder, which in turn progresses irreversibly. The disorder's irreversible progress results in serious impairment of the everyday abilities of those affected, culminating in the complete loss of an independent lifestyle. In-home or institutional care and legal custodianship are often required.
Forms, causes and prevalence of dementia
Irreversible cases, which are mostly neurodegenerative and sometimes neurovascular, are also known as primary dementia. A secondary form of dementia is a functional disorder of brain functions that is fundamentally reversible or curable, such as a brain lesion or neurological disorders caused by poisoning, cardiovascular diseases or thyroid disorders.
Primary dementia accounts for the vast majority of dementia cases today; the following information in this In Focus refers only to these cases. For forms of primary dementia, the majority of clinical syndromes in the global north in 2016 were based on Alzheimer's disease. Other neurodegenerative causes include Parkinson's disease, Creutzfeldt-Jakob disease, Huntington's disease, Lewy body dementia and frontotemporal lobar degeneration, but together these account for only about 10 % of cases. Neurovascular forms, on the other hand, account for about 15 % of cases. The same applies to forms of dementia of a mixed type.
The prevalence of dementia diseases, which in most cases do not occur until an advanced biological age, is increasing worldwide due to an overall increase in life expectancy.
Clinical symptoms and stages of dementia
A general diagnosis of dementia is based on the appearance of the first clinical symptoms and evidence of a biological cause of the disease. Standardized procedures are used to assess the symptoms, in particular memory disorders, other cognitive deficits such as impaired planning and organizational skills, and the significant impairment that these disorders cause in coping with everyday life. Furthermore, differential diagnostics exclude other possible causes such as severe depression as cause of the symptoms. The severity of the impairments allows primary forms of dementia to be divided into three phases with varying degrees of clinical symptoms. The first stage is that of mild dementia. Here the short-term memory is already clearly impaired. Sufferers are still able to live alone, but already struggle to cope with more complex tasks. The second stage is moderate dementia, when memory has become nearly non-functional. Although sufferers still understand familiar and habitual routines, up-to-date information about oneself and close persons can no longer be recalled. An independent life is no longer possible. In the third stage, severe dementia, sufferers no longer express clear thoughts and only have very fragmentary memory and routines. They do no longer recognize close persons. This stage may be accompanied by physical impairments such as movement dysfunctions, incontinence and swallowing disorders. Patients are bedridden and at risk of fatal sepsis or pneumonia.
As dementia progresses, there are significant losses of cognitive abilities and often personality changes. This raises ethical challenges in dealing with dementia patients. Obstacles and uncertainties are encountered in particular when applying established ethical principles.
Dementia and the status as persons
In ethical contexts, certain protection claims are often limited to persons. At the same time, the concept of a person is usually defined on the basis of demanding cognitive capabilities, which include a self-aware reference to the future, the (diachronic) consistent pursuit of preferences over longer periods of time, a reflective evaluation of one's own wishes and actions, and moral motivation and accountability. However, this results in the problematic consequence that dementia patients in the late stages of the disease are no longer considered persons in the true sense of the word, even if we continue to treat them as persons. This view is countered by the objection that passive components of personality remain intact even in the case of dementia and constitute a separate phase of personal life, or that basal forms or core elements of personhood that are less dependent, or not at all, on developed cognitive abilities are still present even in late phases of the disease. From the perspective of theological ethics, the continuing core of personhood of an individual is also emphasized.
Dementia and the continuity of the person in time
There is also uncertainty as to whether a patient in the late stages of the disease is still the same person that he or she was at the beginning or before the onset of the disease, so that, for example, a time-delayed self-determination through earlier expressions of will can be meaningfully achieved. This is not only about possible qualitative changes in personality, but also about the problem of whether at some stage another person may start to inhabit the same body when the current consciousness is no longer linked to the earlier stages of life by memories. An established model of thinking sees the continuity of the person as being based on psychological connections to the past.
This view is countered by the fact that at least fragments of long-term memory are often retained until the end in dementia. These isolated recalls of long-term memory by persons with dementia would therefore provide at least a fragmentary psychological link to their past and thus their continuity as persons.
Another alternative is to base the person's continued diachronic existence rather on physical or neural criteria. Overall, however, it can be concluded that an ethical orientation for normative questions, which cannot be answered without a clarification about the continuity of personal existence across time, is made more difficult by a lack of consensus on the criteria for this diachronic continuation.
These questions have a concrete application dimension, for example, with regard to the applicability of a living will in the event of significant personality changes due to illness or when assessing the culpability of a person suffering from severe dementia.
Dementia and communication
Problems in the application of ethical principles also arise due to the very limited verbal communication with people in the late stages of dementia, whose verbal ability is already greatly reduced. Protecting the autonomy of the patient faces the difficulty that current expressions of will are no longer clearly understandable or carry an increased risk of misunderstanding. The same is true for applying duties of care and the duty to avoid harm in the face of uncertainty as to whether concrete expressions should be interpreted as an expression of positive feelings or of discomfort. At least to a certain extent, however, facial expressions and gestures can still provide differentiated information about wishes and sensitivities.
Dementia and consent to medical treatment
The ethical difficulties associated with the principle of enabling dementia patients to have as much self-determination as possible in the long term are particularly manifold.
In general, the protection of self-determination in the medical context aims to enable patients to give free and informed consent to medical treatment. This also includes the possibility of refusing a measure. With regard to the treatment of people with dementia, the central challenge is to reconcile the decline or complete loss of the ability to consent with the requirement of consent.
In anticipation of the possibility that the ability to consent may be impaired at a later point, all persons with still existing legal capacity have the ability to grant power of attorney to relatives or other trusted persons. The requirement to consent to or reject treatment is in this case prospectively transferred to others.
Furthermore, a conventional institution for safeguarding patient autonomy is the time-delayed effective self-determination by means of a living will, in which a person can stipulate bindingly which medical measures should be taken or omitted if he or she is later unable to make a decision. This form of deferred self-determination is initially based on the previously mentioned, uncertain assumption that the person with dementia is still identical to the competent author of the living will.
In addition to the question of the continuity between the person afflicted with dementia and the still competent person before the onset of the illness, there is the problem that current expressions of will of a person with dementia can contradict the autonomous will of the person still fully capable of making decisions. A prominent example of such a case of conflicting expressions of will is the case of a former rhetoric professor from Tübingen, Walter Jens, who in the stage of advanced dementia expressed a situational will to live that contradicted earlier statements of his own in which he had rejected life-sustaining measures in the case of advanced dementia. This raises the difficult question of whether, in such a case, the predetermining autonomous will should be given greater weight or the so-called "natural will", which is expressed in the later situational expression. Opinions differ on this in ethical discourse, as exemplified by the Dworkin-Dresser debate. In 2012, the German Ethics Council advocated that, in view of the irreversible consequences of failing to take life-saving measures, life-affirming expressions of will in cases where the ability to make decisions cannot be reliably ruled out should be regarded as remnants of self-determination even if they conflict with the advance directives expressed in a living will.
If a person with dementia harms himself or herself through his or her behavior, it is particularly urgent to discuss to what extent the self-determination of a dementia sufferer who is legally incapable of giving consent can or must be subordinated to the care for his or her physical well-being. This debate also includes the discussion around the ethical admissibility of coercive measures such as force-feeding or confinement measures such as restraint, which are legally permissible under certain conditions but ethically controversial.
Dementia and informational self-determination in the context of prediction and early detection
In addition to ethical questions regarding the ability of dementia patients to consent, the right to self-determination also raises ethical questions in the context of medical information. The question of how to deal individually with information about a possibly existing but not yet clinically manifest disease (early detection) or with information about the risk of developing such a disease at a later stage (prediction) may emerge. Prediction and early diagnosis methods and their results nevertheless remain fraught with uncertainty in many areas. Therefore, the value of the possibly obtained medical information must also be carefully assessed in light of the available therapeutic options.
Possibilities to predict dementia
Dementia prediction aims at specifying the risk of later dementia based on an identified disposition or certain risk factors in a person who is healthy at the time of the study.
A first field of application for aspects of autonomy is the decision to undergo a predictive procedure in the case of so-called mild cognitive impairment (MCI). Mild cognitive impairment can be a permanent cognitive disorder in old age, but it can also be a precursor of subsequently developing dementia. If mild cognitive impairment (MCI) is present and biomarkers show specific molecular changes in the brain that are typical of Alzheimer's dementia, it is possible to make more individual risk assessments. In these cases, it is generally possible to predict dementia.
Overall, possibilities of predicting a later dementia disease are currently very limited. One rare form of Alzheimer's dementia that is inherited in an autosomal dominant pattern can be detected with the help of predictive genetic testing.
Early detection of dementia
Prediction of dementia must be distinguished from its early detection or early diagnosis, which is aimed at diagnosing a disease in a person who is often still asymptomatic at a particularly early stage. Both research on prediction and early detection are largely focused on the most common form of Alzheimer's dementia. The preclinical phase of Alzheimer's disease already involves systematic neurodegenerative processes. As the brain reserves compensate for the deficits, the disease remains asymptomatic at clinical level. Early diagnosis is aimed at detecting these processes at an early stage and then, ideally, using therapeutic measures to slow down the progression of the processes and the later disease.
Therapeutic approaches for dementia
There is no available cure for Alzheimer's disease and other primary forms of dementia at present.
Current research into treatment options for dementia is associated with the hope of at least delaying the progression of the disease and its neurodegenerative processes through various interventions. The aim of combined drug and non-drug therapy approaches is to enable dementia patients to cope with everyday activities independently for as long as possible, to maintain the ability to make their own decisions and to enjoy a good quality of life in general. The final, severe phase of dementia usually involves palliative care approaches in the treatment of the affected persons.
Treatment options are to be distinguished from the strategies for preventing dementia. Prevention starts prior to the development of early symptoms and aims at lifestyle-related reduction of risk factors or improvement of protective factors and at the intervention in molecular processes in order to reduce the number of new cases.
Particularly in view of the limited treatment options for dementia, the benefits of predictive testing or early detection are controversial, even irrespective of the methodological uncertainties. For this reason, the aspect of informational self-determination comes into play here in particular, which, according to a common understanding, includes a right not to know.