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Friday, August 30, 2024

Desire

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Desire
Désir, sculpture by Aristide Maillol

Desires can be grouped into various types according to a few basic distinctions. Intrinsic desires concern what the subject wants for its own sake while instrumental desires are about what the subject wants for the sake of something else. Occurrent desires are either conscious or otherwise causally active, in contrast to standing desires, which exist somewhere in the back of one's mind. Propositional desires are directed at possible states of affairs while object-desires are directly about objects. Various authors distinguish between higher desires associated with spiritual or religious goals and lower desires, which are concerned with bodily or sensory pleasures. Desires play a role in many different fields. There is disagreement whether desires should be understood as practical reasons or whether we can have practical reasons without having a desire to follow them. According to fitting-attitude theories of value, an object is valuable if it is fitting to desire this object or if we ought to desire it. Desire-satisfaction theories of well-being state that a person's well-being is determined by whether that person's desires are satisfied.

Marketing and advertising companies have used psychological research on how desire is stimulated to find more effective ways to induce consumers into buying a given product or service. Techniques include creating a sense of lack in the viewer or associating the product with desirable attributes. Desire plays a key role in art. The theme of desire is at the core of romance novels, which often create drama by showing cases where human desire is impeded by social conventions, class, or cultural barriers. Melodrama films use plots that appeal to the heightened emotions of the audience by showing "crises of human emotion, failed romance or friendship", in which desire is thwarted or unrequited.

Theories

Theories of desire aim to define desires in terms of their essential features. A great variety of features are ascribed to desires, like that they are propositional attitudes, that they lead to actions, that their fulfillment tends to bring pleasure, etc. Across the different theories of desires, there is a broad agreement about what these features are. Their disagreement concerns which of these features belong to the essence of desires and which ones are merely accidental or contingent. Traditionally, the two most important theories define desires in terms of dispositions to cause actions or concerning their tendency to bring pleasure upon being fulfilled. An important alternative of more recent origin holds that desiring something means seeing the object of desire as valuable.

General features

A great variety of features is ascribed to desires. They are usually seen as attitudes toward conceivable states of affairs, often referred to as propositional attitudes. They differ from beliefs, which are also commonly seen as propositional attitudes, by their direction of fit. Both beliefs and desires are representations of the world. But while beliefs aim at truth, i.e. to represent how the world actually is, desires aim to change the world by representing how the world should be. These two modes of representation have been termed mind-to-world and world-to-mind direction of fit respectively. Desires can be either positive, in the sense that the subject wants a desirable state to be the case, or negative, in the sense that the subject wants an undesirable state not to be the case. It is usually held that desires come in varying strengths: some things are desired more strongly than other things. We desire things in regard to some features they have but usually not in regard to all of their features.

Desires are also closely related to agency: we normally try to realize our desires when acting. It is usually held that desires by themselves are not sufficient for actions: they have to be combined with beliefs. The desire to own a new mobile phone, for example, can only result in the action of ordering one online if paired with the belief that ordering it would contribute to the desire being fulfilled.he fulfillment of desires is normally experienced as pleasurable in contrast to the negative experience of failing to do so. But independently of whether the desire is fulfilled or not, there is a sense in which the desire presents its object in a favorable light, as something that appears to be good. Besides causing actions and pleasures, desires also have various effects on the mental life. One of these effects is to frequently move the subject's attention to the object of desire, specifically to its positive features. Another effect of special interest to psychology is the tendency of desires to promote reward-based learning, for example, in the form of operant conditioning.

Action-based theories

Action-based or motivational theories have traditionally been dominant. They can take different forms but they all have in common that they define desires as structures that incline us toward actions. This is especially relevant when ascribing desires, not from a first-person perspective, but from a third-person perspective. Action-based theories usually include some reference to beliefs in their definition, for example, that "to desire that P is to be disposed to bring it about that P, assuming one's beliefs are true". Despite their popularity and their usefulness for empirical investigations, action-based theories face various criticisms. These criticisms can roughly be divided into two groups. On the one hand, there are inclinations to act that are not based on desires. Evaluative beliefs about what we should do, for example, incline us toward doing it, even if we do not want to do it. There are also mental disorders that have a similar effect, like the tics associated with Tourette syndrome. On the other hand, there are desires that do not incline us toward action. These include desires for things we cannot change, for example, a mathematician's desire that the number Pi be a rational number. In some extreme cases, such desires may be very common, for example, a totally paralyzed person may have all kinds of regular desires but lacks any disposition to act due to the paralysis.

Pleasure-based theories

It is one important feature of desires that their fulfillment is pleasurable. Pleasure-based or hedonic theories use this feature as part of their definition of desires. According to one version, "to desire p is ... to be disposed to take pleasure in it seeming that p and displeasure in it seeming that not-p". Hedonic theories avoid many of the problems faced by action-based theories: they allow that other things besides desires incline us to actions and they have no problems explaining how a paralyzed person can still have desires. But they also come with new problems of their own. One is that it is usually assumed that there is a causal relation between desires and pleasure: the satisfaction of desires is seen as the cause of the resulting pleasure. But this is only possible if cause and effect are two distinct things, not if they are identical. Apart from this, there may also be bad or misleading desires whose fulfillment does not bring the pleasure they originally seemed to promise.

Value-based theories

Value-based theories are of more recent origin than action-based theories and hedonic theories. They identify desires with attitudes toward values. Cognitivist versions, sometimes referred to as desire-as-belief theses, equate desires with beliefs that something is good, thereby categorizing desires as one type of belief. But such versions face the difficulty of explaining how we can have beliefs about what we should do despite not wanting to do it. A more promising approach identifies desires not with value-beliefs but with value-seemings. On this view, to desire to have one more drink is the same as it seeming good to the subject to have one more drink. But such a seeming is compatible with the subject having the opposite belief that having one more drink would be a bad idea. A closely related theory is due to T. M. Scanlon, who holds that desires are judgments of what we have reasons to do. Critics have pointed out that value-based theories have difficulties explaining how animals, like cats or dogs, can have desires, since they arguably cannot represent things as being good in the relevant sense.

Others

A great variety of other theories of desires have been proposed. Attention-based theories take the tendency of attention to keep returning to the desired object as the defining feature of desires. Learning-based theories define desires in terms of their tendency to promote reward-based learning, for example, in the form of operant conditioning. Functionalist theories define desires in terms of the causal roles played by internal states while interpretationist theories ascribe desires to persons or animals based on what would best explain their behavior. Holistic theories combine various of the aforementioned features in their definition of desires.

Types

Desires can be grouped into various types according to a few basic distinctions. Something is desired intrinsically if the subject desires it for its own sake. Otherwise, the desire is instrumental or extrinsic. Occurrent desires are causally active while standing desires exist somewhere in the back of one's mind. Propositional desires are directed at possible states of affairs, in contrast to object-desires, which are directly about objects.

Intrinsic and instrumental

The distinction between intrinsic and instrumental or extrinsic desires is central to many issues concerning desires. Something is desired intrinsically if the subject desires it for its own sake. Pleasure is a common object of intrinsic desires. According to psychological hedonism, it is the only thing desired intrinsically. Intrinsic desires have a special status in that they do not depend on other desires. They contrast with instrumental desires, in which something is desired for the sake of something else. For example, Haruto enjoys movies, which is why he has an intrinsic desire to watch them. But in order to watch them, he has to step into his car, navigate through the traffic to the nearby cinema, wait in line, pay for the ticket, etc. He desires to do all these things as well, but only in an instrumental manner. He would not do all these things were it not for his intrinsic desire to watch the movie. It is possible to desire the same thing both intrinsically and instrumentally at the same time. So if Haruto was a driving enthusiast, he might have both an intrinsic and an instrumental desire to drive to the cinema. Instrumental desires are usually about causal means to bring the object of another desire about. Driving to the cinema, for example, is one of the causal requirements for watching the movie there. But there are also constitutive means besides causal means. Constitutive means are not causes but ways of doing something. Watching the movie while sitting in seat 13F, for example, is one way of watching the movie, but not an antecedent cause. Desires corresponding to constitutive means are sometimes termed "realizer desires".

Occurrent and standing

Occurrent desires are desires that are currently active. They are either conscious or at least have unconscious effects, for example, on the subject's reasoning or behavior. Desires we engage in and try to realize are occurrent. But we have many desires that are not relevant to our present situation and do not influence us currently. Such desires are called standing or dispositional. They exist somewhere in the back of our minds and are different from not desiring at all despite lacking causal effects at the moment. If Dhanvi is busy convincing her friend to go hiking this weekend, for example, then her desire to go hiking is occurrent. But many of her other desires, like to sell her old car or to talk with her boss about a promotion, are merely standing during this conversation. Standing desires remain part of the mind even while the subject is sound asleep. It has been questioned whether standing desires should be considered desires at all in a strict sense. One motivation for raising this doubt is that desires are attitudes toward contents but a disposition to have a certain attitude is not automatically an attitude itself. Desires can be occurrent even if they do not influence our behavior. This is the case, for example, if the agent has a conscious desire to do something but successfully resists it. This desire is occurrent because it plays some role in the agents mental life, even if it is not action-guiding.

Propositional desires and object-desires

The dominant view is that all desires are to be understood as propositional attitudes. But a contrasting view allows that at least some desires are directed not at propositions or possible states of affairs but directly at objects. This difference is also reflected on a linguistic level. Object-desires can be expressed through a direct object, for example, Louis desires an omelet. Propositional desires, on the other hand, are usually expressed through a that-clause, for example, Arielle desires that she has an omelet for breakfast. Propositionalist theories hold that direct-object-expressions are just a short form for that-clause-expressions while object-desire-theorists contend that they correspond to a different form of desire. One argument in favor of the latter position is that talk of object-desire is very common and natural in everyday language. But one important objection to this view is that object-desires lack proper conditions of satisfaction necessary for desires. Conditions of satisfaction determine under which situations a desire is satisfied. Arielle's desire is satisfied if the that-clause expressing her desire has been realized, i.e. she is having an omelet for breakfast. But Louis's desire is not satisfied by the mere existence of omelets nor by his coming into possession of an omelet at some indeterminate point in his life. So it seems that, when pressed for the details, object-desire-theorists have to resort to propositional expressions to articulate what exactly these desires entail. This threatens to collapse object-desires into propositional desires.

Higher and lower

In religion and philosophy, a distinction is sometimes made between higher and lower desires. Higher desires are commonly associated with spiritual or religious goals in contrast to lower desires, sometimes termed passions, which are concerned with bodily or sensory pleasures. This difference is closely related to John Stuart Mill's distinction between the higher pleasures of the mind and the lower pleasures of the body. In some religions, all desires are outright rejected as a negative influence on our well-being. The second Noble Truth in Buddhism, for example, states that desiring is the cause of all suffering. A related doctrine is also found in the Hindu tradition of karma yoga, which recommends that we act without a desire for the fruits of our actions, referred to as "Nishkam Karma". But other strands in Hinduism explicitly distinguish lower or bad desires for worldly things from higher or good desires for closeness or oneness with God. This distinction is found, for example, in the Bhagavad Gita or in the tradition of bhakti yoga. A similar line of thought is present in the teachings of Christianity. In the doctrine of the seven deadly sins, for example, various vices are listed, which have been defined as perverse or corrupt versions of love. Explicit reference to bad forms of desiring is found, for example, in the sins of lust, gluttony and greed. The seven sins are contrasted with the seven virtues, which include the corresponding positive counterparts. A desire for God is explicitly encouraged in various doctrines. Existentialists sometimes distinguish between authentic and inauthentic desires. Authentic desires express what the agent truly wants from deep within. An agent wants something inauthentically, on the other hand, if the agent is not fully identified with this desire, despite having it.

Roles

Desire is a quite fundamental concept. As such, it is relevant for many different fields. Various definitions and theories of other concepts have been expressed in terms of desires. Actions depend on desires and moral praiseworthiness is sometimes defined in terms of being motivated by the right desire. A popular contemporary approach defines value as that which it is fitting to desire. Desire-satisfaction theories of well-being state that a person's well-being is determined by whether that person's desires are satisfied. It has been suggested that to prefer one thing to another is just to have a stronger desire for the former thing. An influential theory of personhood holds that only entities with higher-order desires can be persons.

Action, practical reasons and morality

Desires play a central role in actions as what motivates them. It is usually held that a desire by itself is not sufficient: it has to be combined with a belief that the action in question would contribute to the fulfillment of the desire. The notion of practical reasons is closely related to motivation and desire. Some philosophers, often from a Humean tradition, simply identify an agent's desires with the practical reasons he has. A closely related view holds that desires are not reasons themselves but present reasons to the agent. A strength of these positions is that they can give a straightforward explanation of how practical reasons can act as motivation. But an important objection is that we may have reasons to do things without a desire to do them. This is especially relevant in the field of morality. Peter Singer, for example, suggests that most people living in developed countries have a moral obligation to donate a significant portion of their income to charities. Such an obligation would constitute a practical reason to act accordingly even for people who feel no desire to do so.

A closely related issue in morality asks not what reasons we have but for what reasons we act. This idea goes back to Immanuel Kant, who holds that doing the right thing is not sufficient from the moral perspective. Instead, we have to do the right thing for the right reason. He refers to this distinction as the difference between legality (Legalität), i.e. acting in accordance with outer norms, and morality (Moralität), i.e. being motivated by the right inward attitude. On this view, donating a significant portion of one's income to charities is not a moral action if the motivating desire is to improve one's reputation by convincing other people of one's wealth and generosity. Instead, from a Kantian perspective, it should be performed out of a desire to do one's duty. These issues are often discussed in contemporary philosophy under the terms of moral praiseworthiness and blameworthiness. One important position in this field is that the praiseworthiness of an action depends on the desire motivating this action.

Value and well-being

It is common in axiology to define value in relation to desire. Such approaches fall under the category of fitting-attitude theories. According to them, an object is valuable if it is fitting to desire this object or if we ought to desire it. This is sometimes expressed by saying that the object is desirable, appropriately desired or worthy of desire. Two important aspects of this type of position are that it reduces values to deontic notions, or what we ought to feel, and that it makes values dependent on human responses and attitudes. Despite their popularity, fitting-attitude theories of value face various theoretical objections. An often-cited one is the wrong kind of reason problem, which is based on the consideration that facts independent of the value of an object may affect whether this object ought to be desired. In one thought experiment, an evil demon threatens the agent to kill her family unless she desires him. In such a situation, it is fitting for the agent to desire the demon in order to save her family, despite the fact that the demon does not possess positive value.

Well-being is usually considered a special type of value: the well-being of a person is what is ultimately good for this person. Desire-satisfaction theories are among the major theories of well-being. They state that a person's well-being is determined by whether that person's desires are satisfied: the higher the number of satisfied desires, the higher the well-being. One problem for some versions of desire theory is that not all desires are good: some desires may even have terrible consequences for the agent. Desire theorists have tried to avoid this objection by holding that what matters are not actual desires but the desires the agent would have if she was fully informed.

Preferences

Desires and preferences are two closely related notions: they are both conative states that determine our behavior. The difference between the two is that desires are directed at one object while preferences concern a comparison between two alternatives, of which one is preferred to the other. The focus on preferences instead of desires is very common in the field of decision theory. It has been argued that desire is the more fundamental notion and that preferences are to be defined in terms of desires. For this to work, desire has to be understood as involving a degree or intensity. Given this assumption, a preference can be defined as a comparison of two desires. That Nadia prefers tea over coffee, for example, just means that her desire for tea is stronger than her desire for coffee. One argument for this approach is due to considerations of parsimony: a great number of preferences can be derived from a very small number of desires. One objection to this theory is that our introspective access is much more immediate in cases of preferences than in cases of desires. So it is usually much easier for us to know which of two options we prefer than to know the degree with which we desire a particular object. This consideration has been used to suggest that maybe preference, and not desire, is the more fundamental notion.

Persons, personhood and higher-order desires

Personhood is what persons have. There are various theories about what constitutes personhood. Most agree that being a person has to do with having certain mental abilities and is connected to having a certain moral and legal status. An influential theory of persons is due to Harry Frankfurt. He defines persons in terms of higher-order desires. Many of the desires we have, like the desire to have ice cream or to take a vacation, are first-order desires. Higher-order desires, on the other hand, are desires about other desires. They are most prominent in cases where a person has a desire he does not want to have. A recovering addict, for example, may have both a first-order desire to take drugs and a second-order desire of not following this first-order desire. Or a religious ascetic may still have sexual desires while at the same time wanting to be free of these desires. According to Frankfurt, having second-order volitions, i.e. second-order desires about which first-order desires are followed, is the mark of personhood. It is a form of caring about oneself, of being concerned with who one is and what one does. Not all entities with a mind have higher-order volitions. Frankfurt terms them "wantons" in contrast to "persons". On his view, animals and maybe also some human beings are wantons.

Formation

Both psychology and philosophy are interested in where desires come from or how they form. An important distinction for this investigation is between intrinsic desires, i.e. what the subject wants for its own sake, and instrumental desires, i.e. what the subject wants for the sake of something else. Instrumental desires depend for their formation and existence on other desires. For example, Aisha has a desire to find a charging station at the airport. This desire is instrumental because it is based on another desire: to keep her mobile phone from dying. Without the latter desire, the former would not have come into existence. As an additional requirement, a possibly unconscious belief or judgment is necessary to the effect that the fulfillment of the instrumental desire would somehow contribute to the fulfillment of the desire it is based on. Instrumental desires usually pass away after the desires they are based on cease to exist. But defective cases are possible where, often due to absentmindedness, the instrumental desire remains. Such cases are sometimes termed "motivational inertia". Something like this might be the case when the agent finds himself with a desire to go to the kitchen, only to realize upon arriving that he does not know what he wants there.

Intrinsic desires, on the other hand, do not depend on other desires. Some authors hold that all or at least some intrinsic desires are inborn or innate, for example, desires for pleasure or for nutrition. But other authors suggest that even these relatively basic desires may depend to some extent on experience: before we can desire a pleasurable object, we have to learn, through a hedonic experience of this object for example, that it is pleasurable. But it is also conceivable that reason by itself generates intrinsic desires. On this view, reasoning to the conclusion that it would be rational to have a certain intrinsic desire causes the subject to have this desire. It has also been proposed that instrumental desires may be transformed into intrinsic desires under the right conditions. This could be possible through processes of reward-based learning. The idea is that whatever reliably predicts the fulfillment of intrinsic desires may itself become the object of an intrinsic desire. So a baby may initially only instrumentally desire its mother because of the warmth, hugs and milk she provides. But over time, this instrumental desire may become an intrinsic desire.

The death-of-desire thesis holds that desires cannot continue to exist once their object is realized. This would mean that an agent cannot desire to have something if he believes that he already has it. One objection to the death-of-desire thesis comes from the fact that our preferences usually do not change upon desire-satisfaction. So if Samuel prefers to wear dry clothes rather than wet clothes, he would continue to hold this preference even after having come home from a rainy day and having changed his clothes. This would indicate against the death-of-desire thesis that no change on the level of the agent's conative states takes place.

Philosophy

In philosophy, desire has been identified as a philosophical problem since Antiquity. In The Republic, Plato argues that individual desires must be postponed in the name of the higher ideal. In De Anima, Aristotle claims that desire is implicated in animal interactions and the propensity of animals to motion; at the same time, he acknowledges that reasoning also interacts with desire.

Thomas Hobbes (1588–1679) proposed the concept of psychological hedonism, which asserts that the "fundamental motivation of all human action is the desire for pleasure." Baruch Spinoza (1632–1677) had a view which contrasted with Hobbes, in that "he saw natural desires as a form of bondage" that are not chosen by a person of their own free will. David Hume (1711–1776) claimed that desires and passions are non-cognitive, automatic bodily responses, and he argued that reasoning is "capable only of devising means to ends set by [bodily] desire".

Immanuel Kant (1724–1804) called any action based on desires a hypothetical imperative, which means they are a command of reason, applying only if one desires the goal in question. Kant also established a relation between the beautiful and pleasure in Critique of Judgment. Georg Wilhelm Friedrich Hegel claimed that "self-consciousness is desire".

Because desire can cause humans to become obsessed and embittered, it has been called one of the causes of woe for mankind.

Religion

Buddhism

In Buddhism, craving (see taṇhā) is thought to be the cause of all suffering that one experiences in human existence. The eradication of craving leads one to ultimate happiness, or Nirvana. However, desire for wholesome things is seen as liberating and enhancing. While the stream of desire for sense-pleasures must be cut eventually, a practitioner on the path to liberation is encouraged by the Buddha to "generate desire" for the fostering of skillful qualities and the abandoning of unskillful ones.

For an individual to effect his or her liberation, the flow of sense-desire must be cut completely; however, while training, he or she must work with motivational processes based on skillfully applied desire. According to the early Buddhist scriptures, the Buddha stated that monks should "generate desire" for the sake of fostering skillful qualities and abandoning unskillful ones.

Christianity

Within Christianity, desire is seen as something that can either lead a person towards God or away from him. Desire is not considered to be a bad thing in and of itself; rather, it is a powerful force within the human that, once submitted to the Lordship of Christ, can become a tool for good, for advancement, and for abundant living.

Hinduism

In Hinduism, the Rig Veda's creation myth Nasadiya Sukta states regarding the one (ekam) spirit: "In the beginning there was Desire (kama) that was first seed of mind. Poets found the bond of being in non-being in their heart's thought".

Psychology

Neuropsychology

While desires are often classified as emotions by laypersons, psychologists often describe desires as ur-emotions, or feelings that do not quite fit the category of basic emotions. For psychologists, desires arise from bodily structures and functions (e.g., the stomach needing food and the blood needing oxygen). On the other hand, emotions arise from a person's mental state. A 2008 study by the University of Michigan indicated that, while humans experience desire and fear as psychological opposites, they share the same brain circuit. A 2008 study entitled "The Neural Correlates of Desire" showed that the human brain categorizes stimuli according to its desirability by activating three different brain areas: the superior orbitofrontal cortex, the mid-cingulate cortex, and the anterior cingulate cortex.

In affective neuroscience, "desire" and "wanting" are operationally defined as motivational salience; the form of "desire" or "wanting" associated with a rewarding stimulus (i.e., a stimulus which acts as a positive reinforcer, such as palatable food, an attractive mate, or an addictive drug) is called "incentive salience" and research has demonstrated that incentive salience, the sensation of pleasure, and positive reinforcement are all derived from neuronal activity within the reward system. Studies have shown that dopamine signaling in the nucleus accumbens shell and endogenous opioid signaling in the ventral pallidum are at least partially responsible for mediating an individual's desire (i.e., incentive salience) for a rewarding stimulus and the subjective perception of pleasure derived from experiencing or "consuming" a rewarding stimulus (e.g., pleasure derived from eating palatable food, sexual pleasure from intercourse with an attractive mate, or euphoria from using an addictive drug). Research also shows that the orbitofrontal cortex has connections to both the opioid and dopamine systems, and stimulating this cortex is associated with subjective reports of pleasure.

Psychoanalysis

Austrian psychiatrist Sigmund Freud, who is best known for his theories of the unconscious mind and the defense mechanism of repression and for creating the clinical practice of psychoanalysis, proposed the notion of the Oedipus complex, which argues that desire for the mother creates neuroses in their sons. Freud used the Greek myth of Oedipus to argue that people desire incest and must repress that desire. He claimed that children pass through several stages, including a stage in which they fixate on the mother as a sexual object. That this "complex" is universal has long since been disputed. Even if it were true, that would not explain those neuroses in daughters, but only in sons. While it is true that sexual confusion can be aberrative in a few cases, there is no credible evidence to suggest that it is a universal scenario. While Freud was correct in labeling the various symptoms behind most compulsions, phobias and disorders, he was largely incorrect in his theories regarding the etiology of what he identified.

French psychoanalyst and psychiatrist Jacques Lacan (1901–1981) argues that desire first occurs during a "mirror phase" of a baby's development, when the baby sees an image of wholeness in a mirror which gives them a desire for that being. As a person matures, Lacan claims that they still feel separated from themselves by language, which is incomplete, and so a person continually strives to become whole. He uses the term "jouissance" to refer to the lost object or feeling of absence (see manque) which a person believes to be unobtainable. Gilles Deleuze rejects the idea, defended by Lacan and other psychoanalysts, that desire is a form of lack related to incompleteness or a lost object. Instead, he holds that it should be understood as a positive reality in the form of an affirmative vital force.

Marketing

In the field of marketing, desire is the human appetite for a given object of attention. Desire for a product is stimulated by advertising, which attempts to give buyers a sense of lack or wanting. In store retailing, merchants attempt to increase the desire of the buyer by showcasing the product attractively, in the case of clothes or jewellery, or, for food stores, by offering samples. With print, TV, and radio advertising, desire is created by giving the potential buyer a sense of lacking ("Are you still driving that old car?") or by associating the product with desirable attributes, either by showing a celebrity using or wearing the product, or by giving the product a "halo effect" by showing attractive models with the product. Nike's "Just Do It" ads for sports shoes are appealing to consumers' desires for self-betterment.

In some cases, the potential buyer already has the desire for the product before they enter the store, as in the case of a decorating buff entering their favorite furniture store. The role of the salespeople in these cases is simply to guide the customer towards making a choice; they do not have to try to "sell" the general idea of making a purchase, because the customer already wants the products. In other cases, the potential buyer does not have a desire for the product or service, and so the company has to create the sense of desire. An example of this situation is for life insurance. Most young adults are not thinking about dying, so they are not naturally thinking about how they need to have accidental death insurance. Life insurance companies, though, are attempting to create a desire for life insurance with advertising that shows pictures of children and asks "If anything happens to you, who will pay for the children's upkeep?".

Marketing theorists call desire the third stage in the hierarchy of effects, which occurs when the buyer develops a sense that if they felt the need for the type of product in question, the advertised product is what would quench their desire.

Artworks

Texts

The theme of desire is at the core of the written fictions, especially romance novels. Novels which are based around the theme of desire, which can range from a long aching feeling to an unstoppable torrent, include Madame Bovary by Gustave Flaubert; Love in the Time of Cholera by Gabriel García Márquez; Lolita by Vladimir Nabokov; Jane Eyre by Charlotte Brontë, and Dracula by Bram Stoker. Brontë's characterization of Jane Eyre depicts her as torn by an inner conflict between reason and desire, because "customs" and "conventionalities" stand in the way of her romantic desires. E.M. Forster's novels use homoerotic codes to describe same-sex desire and longing. Close male friendships with subtle homoerotic undercurrents occur in every novel, which subverts the conventional, heterosexual plot of the novels. In the Gothic-themed Dracula, Stoker depicts the theme of desire which is coupled with fear. When the character Lucy is seduced by Dracula, she describes her sensations in the graveyard as a mixture of fear and blissful emotion.

Poet W. B. Yeats depicts the positive and negative aspects of desire in his poems such as "The Rose for the World", "Adam's Curse", "No Second Troy", "All Things can Tempt me", and "Meditations in Time of Civil War". Some poems depict desire as a poison for the soul; Yeats worked through his desire for his beloved, Maud Gonne, and realized that "Our longing, our craving, our thirsting for something other than Reality is what dissatisfies us". In "The Rose for the World", he admires her beauty, but feels pain because he cannot be with her. In the poem "No Second Troy", Yeats overflows with anger and bitterness because of their unrequited love. Poet T. S. Eliot dealt with the themes of desire and homoeroticism in his poetry, prose and drama. Other poems on the theme of desire include John Donne's poem "To His Mistress Going to Bed", Carol Ann Duffy's longings in "Warming Her Pearls"; Ted Hughes' "Lovesong" about the savage intensity of desire; and Wendy Cope's humorous poem "Song".

Philippe Borgeaud's novels analyse how emotions such as erotic desire and seduction are connected to fear and wrath by examining cases where people are worried about issues of impurity, sin, and shame.

Films

Just as desire is central to the written fiction genre of romance, it is the central theme of melodrama films, which are a subgenre of the drama film. Like drama, a melodrama depends mostly on in-depth character development, interaction, and highly emotional themes. Melodramatic films tend to use plots that appeal to the heightened emotions of the audience. Melodramatic plots often deal with "crises of human emotion, failed romance or friendship, strained familial situations, tragedy, illness, neuroses, or emotional and physical hardship." Film critics sometimes use the term "pejoratively to connote an unrealistic, bathos-filled, campy tale of romance or domestic situations with stereotypical characters (often including a central female character) that would directly appeal to feminine audiences." Also called "women's movies", "weepies", tearjerkers, or "chick flicks".

"Melodrama… is Hollywood's fairly consistent way of treating desire and subject identity", as can be seen in well-known films such as Gone with the Wind, in which "desire is the driving force for both Scarlett and the hero, Rhett". Scarlett desires love, money, the attention of men, and the vision of being a virtuous "true lady". Rhett Butler desires to be with Scarlett, which builds to a burning longing that is ultimately his undoing, because Scarlett keeps refusing his advances; when she finally confesses her secret desire, Rhett is worn out and his longing is spent.

In Cathy Cupitt's article on "Desire and Vision in Blade Runner", she argues that film, as a "visual narrative form, plays with the voyeuristic desires of its audience". Focusing on the dystopian 1980s science fiction film Blade Runner, she calls the film an "Object of Visual Desire", in which it plays to an "expectation of an audience's delight in visual texture, with the 'retro-fitted' spectacle of the post-modern city to ogle" and with the use of the "motif of the 'eye'". In the film, "desire is a key motivating influence on the narrative of the film, both in the 'real world', and within the text."

Libido

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Libido

In psychology, libido (/lɪˈbd/; from the Latin libīdō, 'desire') is psychic drive or energy, usually conceived as sexual in nature, but sometimes conceived as including other forms of desire. The term libido was originally used by the neurologist and pioneering psychoanalyst Sigmund Freud who began by employing it simply to denote sexual desire. Over time it came to signify the psychic energy of the sexual drive, and became a vital concept in psychoanalytic theory. Freud's later conception was broadened to include the fundamental energy of all expressions of love, pleasure, and self-preservation.

In common or colloquial usage, a person's overall sexual drive is often referred to as that person's "libido". In this sense, libido is influenced by biological, psychological, and social factors. Biologically, the sex hormones and associated neurotransmitters that act upon the nucleus accumbens (primarily testosterone, estrogen, and dopamine, respectively) regulate sex drive in humans. Sexual drive can be affected by social factors such as work and family; psychological factors such as personality and stress; also by medical conditions, medications, lifestyle, relationship issues, and age.

Psychological perspectives

Sigmund Freud, who is considered the originator of the modern use of the term, defined libido as "the energy, regarded as a quantitative magnitude... of those instincts which have to do with all that may be comprised under the word 'love'." It is the instinctual energy or force, contained in what Freud called the id, the strictly unconscious structure of the psyche. He also explained that it is analogous to hunger, the will to power, and so on insisting that it is a fundamental instinct that is innate in all humans.

Freud pointed out that these libidinal drives can conflict with the conventions of civilised behavior, represented in the psyche by the superego. It is this need to conform to society and control the libido that leads to tension and anxiety in the individual, prompting the use of ego defenses which channel the psychic energy of the unconscious drives into forms that are acceptable to the ego and superego. Excessive use of ego defenses results in neurosis, so a primary goal of psychoanalysis is to make the drives accessible to consciousness, allowing them to be addressed directly, thus reducing the patient's automatic resort to ego defenses.

Freud viewed libido as passing through a series of developmental stages in the individual, in which the libido fixates on different erogenous zones: first the oral stage (exemplified by an infant's pleasure in nursing), then the anal stage (exemplified by a toddler's pleasure in controlling his or her bowels), then the phallic stage, through a latency stage in which the libido is dormant, to its reemergence at puberty in the genital stage (Karl Abraham would later add subdivisions in both oral and anal stages.). Failure to adequately adapt to the demands of these different stages could result in libidinal energy becoming 'dammed up' or fixated in these stages, producing certain pathological character traits in adulthood.

Jung

Swiss psychiatrist Carl Gustav Jung identified the libido with psychic energy in general. According to Jung, 'energy', in its subjective and psychological sense, is 'desire', of which sexual desire is just one aspect. Libido thus denotes "a desire or impulse which is unchecked by any kind of authority, moral or otherwise. Libido is appetite in its natural state. From the genetic point of view it is bodily needs like hunger, thirst, sleep, and sex, and emotional states or affects, which constitute the essence of libido." It is "the energy that manifests itself in the life process and is perceived subjectively as striving and desire." Duality (opposition) creates the energy (or libido) of the psyche, which Jung asserts expresses itself only through symbols. These symbols may manifest as "fantasy-images" in the process of psychoanalysis, giving subjective expression to the contents of the libido, which otherwise lacks any definite form. Desire, conceived generally as a psychic longing, movement, displacement and structuring, manifests itself in definable forms which are apprehended through analysis.

Other psychological and social perspectives

A person may have a desire for sex, but not have the opportunity to act on that desire, or may on personal, moral or religious reasons refrain from acting on the urge. Psychologically, a person's urge can be repressed or sublimated. Conversely, a person can engage in sexual activity without an actual desire for it. Multiple factors affect human sex drive, including stress, illness, pregnancy, and others. A 2001 review found that, on average, men have a higher desire for sex than women.

Certain psychological or social factors can reduce the desire for sex. These factors can include lack of privacy or intimacy, stress or fatigue, distraction, or depression. Environmental stress, such as prolonged exposure to elevated sound levels or bright light, can also affect libido. Other causes include experience of sexual abuse, assault, trauma, or neglect, body image issues, and anxiety about engaging in sexual activity.

Individuals with post-traumatic stress disorder (PTSD) may find themselves with reduced sexual desire. Struggling to find pleasure, as well as having trust issues, many with PTSD experience feelings of vulnerability, rage and anger, and emotional shutdowns, which have been shown to inhibit sexual desire in those with PTSD. Reduced sex drive may also be present in trauma victims due to issues arising in sexual function. For women, it has been found that treatment can improve sexual function, thus helping restore sexual desire. Depression and libido decline often coincide, with reduced sex drive being one of the symptoms of depression. Those with depression often report the decline in libido to be far reaching and more noticeable than other symptoms. In addition, those with depression often are reluctant to report their reduced sex drive, often normalizing it with cultural/social values, or by the failure of the physician to inquire about it.

Sexual desires are often an important factor in the formation and maintenance of intimate relationships in humans. A lack or loss of sexual desire can adversely affect relationships. Changes in the sexual desires of any partner in a sexual relationship, if sustained and unresolved, may cause problems in the relationship. The infidelity of a partner may be an indication that a partner's changing sexual desires can no longer be satisfied within the current relationship. Problems can arise from disparity of sexual desires between partners, or poor communication between partners of sexual needs and preferences.

Biological perspectives

Endogenous compounds

Libido is governed primarily by activity in the mesolimbic dopamine pathway (ventral tegmental area and nucleus accumbens). Consequently, dopamine and related trace amines (primarily phenethylamine) that modulate dopamine neurotransmission play a critical role in regulating libido.

Other neurotransmitters, neuropeptides, and sex hormones that affect sex drive by modulating activity in or acting upon this pathway include:

Sex hormone levels and the menstrual cycle

A woman's desire for sex is correlated to her menstrual cycle, with many women experiencing a heightened sexual desire in the several days immediately before ovulation, which is her peak fertility period, which normally occurs two days before and until two days after the ovulation. This cycle has been associated with changes in a woman's testosterone levels during the menstrual cycle. According to Gabrielle Lichterman, testosterone levels have a direct impact on a woman's interest in sex. According to her, testosterone levels rise gradually from about the 24th day of a woman's menstrual cycle until ovulation on about the 14th day of the next cycle, and during this period the woman's desire for sex increases consistently. The 13th day is generally the day with the highest testosterone levels. In the week following ovulation, the testosterone level is the lowest and as a result women will experience less interest in sex.

Also, during the week following ovulation, progesterone levels increase, resulting in a woman experiencing difficulty achieving orgasm. Although the last days of the menstrual cycle are marked by a constant testosterone level, women's libido may get a boost as a result of the thickening of the uterine lining which stimulates nerve endings and makes a woman feel aroused. Also, during these days, estrogen levels decline, resulting in a decrease of natural lubrication.

Although some specialists disagree with this theory, menopause is still considered by the majority a factor that can cause decreased sexual desire in women. The levels of estrogen decrease at menopause and this usually causes a lower interest in sex and vaginal dryness which makes sex painful. However, the levels of testosterone increase at menopause and this may be why some women may experience a contrary effect of an increased libido.

Physical factors

Physical factors that can affect libido include endocrine issues such as hypothyroidism, the effect of certain prescription medications (for example flutamide), and the attractiveness and biological fitness of one's partner, among various other lifestyle factors.

Anemia is a cause of lack of libido in women due to the loss of iron during the period.

Smoking tobacco, alcohol use disorder, and the use of certain drugs can also lead to a decreased libido. Moreover, specialists suggest that several lifestyle changes such as exercising, quitting smoking, lowering consumption of alcohol or using prescription drugs may help increase one's sexual desire.

Medications

Some people purposefully attempt to decrease their libido through the usage of anaphrodisiacs. Aphrodisiacs, such as dopaminergic psychostimulants, are a class of drugs which can increase libido. On the other hand, a reduced libido is also often iatrogenic and can be caused by many medications, such as hormonal contraception, SSRIs and other antidepressants, antipsychotics, opioids, beta blockers and isotretinoin.

Isotretinoin, finasteride and many SSRIs uncommonly can cause a long-term decrease in libido and overall sexual function, sometimes lasting for months or years after users of these drugs have stopped taking them. These long-lasting effects have been classified as iatrogenic medical disorders, respectively termed post-retinoid sexual dysfunction/post-Accutane syndrome (PRSD/PAS), post-finasteride syndrome (PFS) and post-SSRI sexual dysfunction (PSSD). These three disorders share many overlapping symptoms in addition to reduced libido, and are thought to share a common etiology, but collectively remain poorly-understood and lack effective treatments.

Multiple studies have shown that with the exception of bupropion (Wellbutrin), trazodone (Desyrel) and nefazodone (Serzone), antidepressants generally will lead to lowered libido. SSRIs that typically lead to decreased libido are fluoxetine (Prozac), paroxetine (Paxil), fluvoxamine (Luvox), citalopram (Celexa) and sertraline (Zoloft). Some antidepressant users have tried decreasing their dosage in the hopes of maintaining an adequate sex drive. Other users try enrolling in psychotherapy to solve depression-related issues of libido. However, the effectiveness of this therapy is mixed, with many reporting that it had no or little effect on sexual drive.

Testosterone is one of the hormones controlling libido in human beings. Emerging research is showing that hormonal contraception methods like oral contraceptive pills (which rely on estrogen and progesterone together) are causing low libido in females by elevating levels of sex hormone-binding globulin (SHBG). SHBG binds to sex hormones, including testosterone, rendering them unavailable. Research is showing that even after ending a hormonal contraceptive method, SHBG levels remain elevated and no reliable data exists to predict when this phenomenon will diminish.

Oral contraceptives lower androgen levels in users, and lowered androgen levels generally lead to a decrease in sexual desire. However, usage of oral contraceptives has shown to typically not have a connection with lowered libido in women.

Effects of age

Males reach the peak of their sex drive in their teenage years, while females reach it in their thirties. The surge in testosterone hits the male at puberty resulting in a sudden and extreme sex drive which reaches its peak at age 15–16, then drops slowly over their lifetime. In contrast, a female's libido increases slowly during adolescence and peaks in their mid-thirties. Actual testosterone and estrogen levels that affect a person's sex drive vary considerably.

Some boys and girls will start expressing romantic or sexual interest by age 10–12. The romantic feelings are not necessarily sexual, but are more associated with attraction and desire for another. For boys and girls in their preteen years (ages 11–12), at least 25% report "thinking a lot about sex". By the early teenage years (ages 13–14), however, boys are much more likely to have sexual fantasies than girls. In addition, boys are much more likely to report an interest in sexual intercourse at this age than girls. Masturbation among youth is common, with prevalence among the population generally increasing until the late 20s and early 30s. Boys generally start masturbating earlier, with less than 10% boys masturbating around age 10, around half participating by age 11–12, and over a substantial majority by age 13–14. This is in sharp contrast to girls where virtually none are engaging in masturbation before age 13, and only around 20% by age 13–14.

People in their 60s and early 70s generally retain a healthy sex drive, but this may start to decline in the early to mid-70s. Older adults generally develop a reduced libido due to declining health and environmental or social factors. In contrast to common belief, postmenopausal women often report an increase in sexual desire and an increased willingness to satisfy their partner. Women often report family responsibilities, health, relationship problems, and well-being as inhibitors to their sexual desires. Aging adults often have more positive attitudes towards sex in older age due to being more relaxed about it, freedom from other responsibilities, and increased self-confidence. Those exhibiting negative attitudes generally cite health as one of the main reasons. Stereotypes about aging adults and sexuality often regard seniors as asexual beings, doing them no favors when they try to talk about sexual interest with caregivers and medical professionals. Non-western cultures often follow a narrative of older women having a much lower libido, thus not encouraging any sort of sexual behavior for women. Residence in retirement homes has effects on residents' libidos. In these homes, sex occurs, but it is not encouraged by the staff or other residents. Lack of privacy and resident gender imbalance are the main factors lowering desire. Generally, for older adults, being excited about sex, good health, sexual self-esteem and having a sexually talented partner can be factors.

Sexual desire disorders

Sexual desire disorders are more common in women than in men, and women tend to exhibit less frequent and less intense sexual desires than men. Erectile dysfunction may happen to the penis because of lack of sexual desire, but these two should not be confused since the two can commonly occur simultaneously. For example, moderate to large recreational doses of cocaine, amphetamine or methamphetamine can simultaneously cause erectile dysfunction (evidently due to vasoconstriction) while still significantly increasing libido due to heightened levels of dopamine. Although conversely, excessive or very regular/repeated high-dose amphetamine use may damage leydig cells in the male testes, potentially leading to markedly lowered sexual desire subsequently due to hypogonadism. However in contrast to this, other stimulants such as cocaine and even caffeine appear to lack negative impacts on testosterone levels, and may even increase their concentrations in the body. Studies on cannabis however seem to be exceptionally mixed, with some claiming decreased levels on testosterone, others reporting increased levels, and with some showing no measurable changes at all. This varying data seems to coincide with the almost equally conflicting data on cannabis' effects on sex drive as well, which may be dosage or frequency-dependent, due to different amounts of distinct cannabinoids in the plant, or based on individual enzyme properties responsible for metabolism of the drug. Evidence on alcohol's effects on testosterone however invariably show a clear decrease, however (like amphetamine, albeit to a lesser degree); temporary increases in libido and related sexual behavior have long been observed during alcohol intoxication in both sexes, but likely most noticeable with moderation, particularly in males. Additionally, men often also naturally experience a decrease in their libido as they age due to decreased productions in testosterone.

The American Medical Association has estimated that several million US women have a female sexual arousal disorder, though arousal is not at all synonymous with desire, so this finding is of limited relevance to the discussion of libido. Some specialists claim that women may experience low libido due to some hormonal abnormalities such as lack of luteinising hormone or androgenic hormones, although these theories are still controversial.

Creutzfeldt–Jakob disease

 

From Wikipedia, the free encyclopedia
Creutzfeldt–Jakob disease
Other namesClassic Creutzfeldt–Jakob disease, subacute spongiform encephalopathy, neurocognitive disorder due to prion disease, (historical) spastic pseudosclerosis
Magnetic resonance image of sporadic CJD
Pronunciation
SpecialtyNeurology
Symptoms
  • Early: memory problems, behavioral changes, poor coordination, visual disturbances
  • Later: dementia, involuntary movements, blindness, weakness, coma
ComplicationsAspiration pneumonia due to difficulty coughing and swallowing
Usual onsetAround 60
Duration70% die within a year of diagnosis
TypesSporadic (mutation), Familial (heredity), Iatrogenic (acquired), Variant (infection)
CausesPrion
Risk factorsHaving at least one living or deceased ancestor with the disease (in case of familial CJD)
Diagnostic methodBased on symptoms and medical tests after other possible causes are ruled out
Differential diagnosisEncephalitis, chronic meningitis, Huntington's disease, Alzheimer's disease, Sjögren's syndrome
PreventionGene editing of children at risk (for fCJD)
TreatmentNone, only supportive care as this condition is untreatable
MedicationVarious experimental treatments, For pain relief: Morphine, Methadone
PrognosisLife expectancy greatly shortened, varies from 3 months to multiple years
Frequency1 per million per year
Deaths131 in the United Kingdom (2020)

Creutzfeldt–Jakob disease (CJD), also known as subacute spongiform encephalopathy or neurocognitive disorder due to prion disease, is a fatal neurodegenerative disease. Early symptoms include memory problems, behavioral changes, poor coordination, and visual disturbances. Later symptoms include dementia, involuntary movements, blindness, weakness, and coma. About 70% of people die within a year of diagnosis. The name "Creutzfeldt–Jakob disease" was introduced by Walther Spielmeyer in 1922, after the German neurologists Hans Gerhard Creutzfeldt and Alfons Maria Jakob.

CJD is caused by abnormal folding of a protein known as a prion. Infectious prions are misfolded proteins that can cause normally folded proteins to also become misfolded. About 85% of cases of CJD occur for unknown reasons, while about 7.5% of cases are inherited in an autosomal dominant manner. Exposure to brain or spinal tissue from an infected person may also result in spread. There is no evidence that sporadic CJD can spread among people via normal contact or blood transfusions, although this is possible in variant Creutzfeldt–Jakob disease. Diagnosis involves ruling out other potential causes. An electroencephalogram, spinal tap, or magnetic resonance imaging may support the diagnosis.

There is no specific treatment for CJD. Opioids may be used to help with pain, while clonazepam or sodium valproate may help with involuntary movements. CJD affects about one person per million people per year. Onset is typically around 60 years of age. The condition was first described in 1920. It is classified as a type of transmissible spongiform encephalopathy. Inherited CJD accounts for about 10% of prion disease cases. Sporadic CJD is different from bovine spongiform encephalopathy (mad cow disease) and variant Creutzfeldt–Jakob disease (vCJD).

Signs and symptoms

The first symptom of CJD is usually rapidly progressive dementia, leading to memory loss, personality changes, and hallucinations. Myoclonus (jerky movements) typically occurs in 90% of cases, but may be absent at initial onset. Other frequently occurring features include anxiety, depression, paranoia, obsessive-compulsive symptoms, and psychosis. This is accompanied by physical problems such as speech impairment, balance and coordination dysfunction (ataxia), changes in gait, and rigid posture. In most people with CJD, these symptoms are accompanied by involuntary movements. The duration of the disease varies greatly, but sporadic (non-inherited) CJD can be fatal within months or even weeks. Most affected people die six months after initial symptoms appear, often of pneumonia due to impaired coughing reflexes. About 15% of people with CJD survive for two or more years.

The symptoms of CJD are caused by the progressive death of the brain's nerve cells, which are associated with the build-up of abnormal prion proteins forming in the brain. When brain tissue from a person with CJD is examined under a microscope, many tiny holes can be seen where the nerve cells have died. Parts of the brain may resemble a sponge where the prions were infecting the areas of the brain.

Cause

CJD is a type of transmissible spongiform encephalopathy (TSE), which are caused by prions. Prions are misfolded proteins that occur in the neurons of the central nervous system (CNS). They are thought to affect signaling processes, damaging neurons and resulting in degeneration that causes the spongiform appearance in the affected brain.

The CJD prion is dangerous because it promotes refolding of the cellular prion protein into the diseased state. The number of misfolded protein molecules will increase exponentially and the process leads to a large quantity of insoluble protein in affected cells. This mass of misfolded proteins disrupts neuronal cell function and causes cell death. Mutations in the gene for the prion protein can cause a misfolding of the dominantly alpha helical regions into beta pleated sheets. This change in conformation disables the ability of the protein to undergo digestion. Once the prion is transmitted, the defective proteins invade the brain and induce other prion protein molecules to misfold in a self-sustaining feedback loop. These neurodegenerative diseases are commonly called prion diseases.

Transmission

MRI of iCJD because of growth hormone

The defective protein can be transmitted by contaminated harvested human brain products, corneal grafts, dural grafts, or electrode implants and human growth hormone.

It can be familial (fCJD); or it may appear without clear risk factors (sporadic form: sCJD). In the familial form, a mutation has occurred in the gene for PrP, PRNP, in that family. All types of CJD are transmissible irrespective of how they occur in the person.

It is thought that humans can contract the variant form of the disease by eating food from animals infected with bovine spongiform encephalopathy (BSE), the bovine form of TSE also known as mad cow disease. However, it can also cause sCJD in some cases.

Cannibalism has also been implicated as a transmission mechanism for abnormal prions, causing the disease known as kuru, once found primarily among women and children of the Fore people in Papua New Guinea, who previously engaged in funerary cannibalism. While the men of the tribe ate the muscle tissue of the deceased, women and children consumed other parts, such as the brain, and were more likely than men to contract kuru from infected tissue.

Prions, the infectious agent of CJD, may not be inactivated by means of routine surgical instrument sterilization procedures. The World Health Organization and the US Centers for Disease Control and Prevention recommend that instrumentation used in such cases be immediately destroyed after use; short of destruction, it is recommended that heat and chemical decontamination be used in combination to process instruments that come in contact with high-infectivity tissues. Thermal depolymerization also destroys prions in infected organic and inorganic matter, since the process chemically attacks protein at the molecular level, although more effective and practical methods involve destruction by combinations of detergents and enzymes similar to biological washing powders.

Genetics

People can also develop CJD because they carry a mutation of the gene that codes for the prion protein (PRNP), located on chromosome 202p12-pter. This occurs in only 10–15% of all CJD cases. In sporadic cases, the misfolding of the prion protein is a process that is hypothesized to occur as a result of the effects of aging on cellular machinery, explaining why the disease often appears later in life. An EU study determined that "87% of cases were sporadic, 8% genetic, 5% iatrogenic and less than 1% variant."

Diagnosis

Through the image of MRI, the obvious precipitation of prion protein in the brain is visible.

Testing for CJD has historically been problematic, due to nonspecific nature of early symptoms and difficulty in safely obtaining brain tissue for confirmation. The diagnosis may initially be suspected in a person with rapidly progressing dementia, particularly when they are also found with the characteristic medical signs and symptoms such as involuntary muscle jerking, difficulty with coordination/balance and walking, and visual disturbances. Further testing can support the diagnosis and may include:

  • Electroencephalography – may have characteristic generalized periodic sharp wave pattern. Periodic sharp wave complexes develop in half of the people with sporadic CJD, particularly in the later stages.
  • Cerebrospinal fluid (CSF) analysis for elevated levels of 14-3-3 protein could be supportive in the diagnosis of sCJD. However, a positive result should not be regarded as sufficient for the diagnosis. The Real-Time Quaking-Induced Conversion (RT-QuIC) assay has a diagnostic sensitivity of more than 80% and a specificity approaching 100%, tested in detecting PrPSc in CSF samples of people with CJD. It is therefore suggested as a high-value diagnostic method for the disease.
  • MRI of the brain – often shows high signal intensity in the caudate nucleus and putamen bilaterally on T2-weighted images.

In recent years, studies have shown that the tumour marker neuron-specific enolase (NSE) is often elevated in CJD cases; however, its diagnostic utility is seen primarily when combined with a test for the 14-3-3 protein. As of 2010, screening tests to identify infected asymptomatic individuals, such as blood donors, are not yet available, though methods have been proposed and evaluated.

Imaging

Imaging of the brain may be performed during medical evaluation, both to rule out other causes and to obtain supportive evidence for diagnosis. Imaging findings are variable in their appearance, and also variable in sensitivity and specificity. While imaging plays a lesser role in diagnosis of CJD, characteristic findings on brain MRI in some cases may precede onset of clinical manifestations.

Brain MRI is the most useful imaging modality for changes related to CJD. Of the MRI sequences, diffuse-weighted imaging sequences are most sensitive. Characteristic findings are as follows:

dwMRI, FDG PET and post mortem histology from a patient who presented with sCJD aged 66
  • Focal or diffuse diffusion-restriction involving the cerebral cortex and/or basal ganglia. In about 24% of cases DWI shows only cortical hyperintensity; in 68%, cortical and subcortical abnormalities; and in 5%, only subcortical anomalies. The most iconic and striking cortical abnormality has been called "cortical ribboning" or "cortical ribbon sign" due to hyperintensities resembling ribbons appearing in the cortex on MRI. The involvement of the thalamus can be found in sCJD, is even stronger and constant in vCJD.
  • Varying degree of symmetric T2 hyperintense signal changes in the basal ganglia (i.e., caudate and putamen), and to a lesser extent globus pallidus and occipital cortex.
  • Cerebellar atrophy

Brain FDG PET-CT tends to be markedly abnormal, and is increasingly used in the investigation of dementias.

  • Patients with CJD will normally have hypometabolism on FDG PET.

Histopathology

Spongiform change in CJD

Testing of tissue remains the most definitive way of confirming the diagnosis of CJD, although it must be recognized that even biopsy is not always conclusive.

In one-third of people with sporadic CJD, deposits of "prion protein (scrapie)", PrPSc, can be found in the skeletal muscle and/or the spleen. Diagnosis of vCJD can be supported by biopsy of the tonsils, which harbor significant amounts of PrPSc; however, biopsy of brain tissue is the definitive diagnostic test for all other forms of prion disease. Due to its invasiveness, biopsy will not be done if clinical suspicion is sufficiently high or low. A negative biopsy does not rule out CJD, since it may predominate in a specific part of the brain.

The classic histologic appearance is spongiform change in the gray matter: the presence of many round vacuoles from one to 50 micrometers in the neuropil, in all six cortical layers in the cerebral cortex or with diffuse involvement of the cerebellar molecular layer. These vacuoles appear glassy or eosinophilic and may coalesce. Neuronal loss and gliosis are also seen. Plaques of amyloid-like material can be seen in the neocortex in some cases of CJD.

However, extra-neuronal vacuolization can also be seen in other disease states. Diffuse cortical vacuolization occurs in Alzheimer's disease, and superficial cortical vacuolization occurs in ischemia and frontotemporal dementia. These vacuoles appear clear and punched-out. Larger vacuoles encircling neurons, vessels, and glia are a possible processing artifact.

Classification

Types of CJD include:

  • Sporadic (sCJD), caused by the spontaneous misfolding of prion-protein in an individual. This accounts for 85% of cases of CJD.
  • Familial (fCJD), caused by an inherited mutation in the prion-protein gene. This accounts for the majority of the other 15% of cases of CJD.
  • Acquired CJD, caused by contamination with tissue from an infected person, usually as the result of a medical procedure (iatrogenic CJD). Medical procedures that are associated with the spread of this form of CJD include blood transfusion from the infected person, use of human-derived pituitary growth hormones, gonadotropin hormone therapy, and corneal and meningeal transplants. Variant Creutzfeldt–Jakob disease (vCJD) is a type of acquired CJD potentially acquired from bovine spongiform encephalopathy or caused by consuming food contaminated with prions.
Clinical and pathologic characteristics
Characteristic Classic CJD Variant CJD
Median age at death 68 years 28 years
Median duration of illness 4–5 months 13–14 months
Clinical signs and symptoms Dementia; early neurologic signs Prominent psychiatric/behavioral symptoms; painful dysesthesias; delayed neurologic signs
Periodic sharp waves on electroencephalogram Often present Often absent
Signal hyperintensity in the caudate nucleus and putamen on diffusion-weighted and FLAIR MRI Often present Often absent
Pulvinar sign-bilateral high signal intensities on axial FLAIR MRI. Also posterior thalamic involvement on sagittal T2 sequences Not reported Present in >75% of cases
Immunohistochemical analysis of brain tissue Variable accumulation. Marked accumulation of protease-resistant prion protein
Presence of agent in lymphoid tissue Not readily detected Readily detected
Increased glycoform ratio on immunoblot analysis of protease-resistant prion protein Not reported Marked accumulation of protease-resistant prion protein
Presence of amyloid plaques in brain tissue May be present May be present

Treatment

As of 2024, there is no cure or effective treatment for CJD. Some of the symptoms like twitching can be managed, but otherwise treatment is palliative care. Psychiatric symptoms like anxiety and depression can be treated with sedatives and antidepressants. Myoclonic jerks can be handled with clonazepam or sodium valproate. Opiates can help in pain. Seizures are very uncommon but can nevertheless be treated with antiepileptic drugs.

Prognosis

Life expectancy is greatly reduced for people with Creutzfeldt–Jakob disease, with the average being less than 6 months. As of 1981, no one was known to have lived longer than 2.5 years after the onset of CJD symptoms. In 2011, Jonathan Simms, a Northern Irish man who lived 10 years after his diagnosis, was reported to be one of the world's longest survivors of variant Creutzfeldt–Jakob disease (vCJD).

Epidemiology

CDC monitors the occurrence of CJD in the United States through periodic reviews of national mortality data. According to the CDC:

  • CJD occurs worldwide at a rate of about 1 case per million population per year.
  • On the basis of mortality surveillance from 1979 to 1994, the annual incidence of CJD remained stable at approximately 1 case per million people in the United States.
  • In the United States, CJD deaths among people younger than 30 years of age are extremely rare (fewer than five deaths per billion per year).
  • The disease is found most frequently in people 55–65 years of age, but cases can occur in people older than 90 years and younger than 55 years of age.
  • In more than 85% of cases, the duration of CJD is less than one year (median: four months) after the onset of symptoms.

Further information from the CDC:

  • Risk of developing CJD increases with age.
  • CJD incidence was 3.5 cases per million among those over 50 years of age between 1979 and 2017.
  • Approximately 85% of CJD cases are sporadic and 10–15% of CJD cases are due to inherited mutations of the prion protein gene.
  • CJD deaths and age-adjusted death rate in the United States indicate an increasing trend in the number of deaths between 1979 and 2017.

Although not fully understood, additional information suggests that CJD rates in African American and nonwhite groups are lower than in whites. While the mean onset is approximately 67 years of age, cases of sCJD have been reported as young as 17 years and over 80 years of age. Mental capabilities rapidly deteriorate and the average amount of time from onset of symptoms to death is 7 to 9 months.

According to a 2020 systematic review on the international epidemiology of CJD:

  • Surveillance studies from 2005 and later show the estimated global incidence is 1–2 cases per million population per year.
  • Sporadic CJD (sCJD) incidence increased from the years 1990–2018 in the UK.
  • Probable or definite sCJD deaths also increased from the years 1996–2018 in twelve additional countries.
  • CJD incidence is greatest in those over the age of 55 years old, with an average age of 67 years old.

The intensity of CJD surveillance increases the number of reported cases, often in countries where CJD epidemics have occurred in the past and where surveillance resources are greatest. An increase in surveillance and reporting of CJD is most likely in response to BSE and vCJD. Possible factors contributing to an increase of CJD incidence are an aging population, population increase, clinician awareness, and more accurate diagnostic methods. Since CJD symptoms are similar to other neurological conditions, it is also possible that CJD is mistaken for stroke, acute nephropathy, general dementia, and hyperparathyroidism.

History

The disease was first described by German neurologist Hans Gerhard Creutzfeldt in 1920 and shortly afterward by Alfons Maria Jakob, giving it the name Creutzfeldt–Jakob disease. Some of the clinical findings described in their first papers do not match current criteria for Creutzfeldt–Jakob disease, and it has been speculated that at least two of the people in initial studies had a different ailment. An early description of familial CJD stems from the German psychiatrist and neurologist Friedrich Meggendorfer (1880–1953). A study published in 1997 counted more than 100 cases worldwide of transmissible CJD and new cases continued to appear at the time.

The first report of suspected iatrogenic CJD was published in 1974. Animal experiments showed that corneas of infected animals could transmit CJD, and the causative agent spreads along visual pathways. A second case of CJD associated with a corneal transplant was reported without details. In 1977, CJD transmission caused by silver electrodes previously used in the brain of a person with CJD was first reported. Transmission occurred despite the decontamination of the electrodes with ethanol and formaldehyde. Retrospective studies identified four other cases likely of similar cause. The rate of transmission from a single contaminated instrument is unknown, although it is not 100%. In some cases, the exposure occurred weeks after the instruments were used on a person with CJD. In the 1980s it was discovered that Lyodura, a dura mater transplant product, was shown to transmit CJD from the donor to the recipient. This led to the product being banned in Canada but it was used in other countries such as Japan until 1993.

A review article published in 1979 indicated that 25 dura mater cases had occurred by that date in Australia, Canada, Germany, Italy, Japan, New Zealand, Spain, the United Kingdom, and the United States.

By 1985, a series of case reports in the United States showed that when injected, cadaver-extracted pituitary human growth hormone could transmit CJD to humans.

In 1992, it was recognized that human gonadotropin administered by injection could also transmit CJD from person to person.

Stanley B. Prusiner of the University of California, San Francisco (UCSF) was awarded the Nobel Prize in Physiology or Medicine in 1997 "for his discovery of Prions—a new biological principle of infection".

Yale University neuropathologist Laura Manuelidis has challenged the prion protein (PrP) explanation for the disease. In January 2007, she and her colleagues reported that they had found a virus-like particle in naturally and experimentally infected animals. "The high infectivity of comparable, isolated virus-like particles that show no intrinsic PrP by antibody labeling, combined with their loss of infectivity when nucleic acid–protein complexes are disrupted, make it likely that these 25-nm particles are the causal TSE virions".

Australia

Australia has documented 10 cases of healthcare-acquired CJD (iatrogenic or ICJD). Five of the deaths resulted after the patients, who were in treatment either for infertility or short stature, were treated using contaminated pituitary extract hormone but no new cases have been noted since 1991. The other five deaths occurred due to dura grafting procedures that were performed during brain surgery, in which the covering of the brain is repaired. There have been no other ICJD deaths documented in Australia due to transmission during healthcare procedures.

New Zealand

A case was reported in 1989 in a 25-year-old man from New Zealand, who also received dura mater transplant. Five New Zealanders have been confirmed to have died of the sporadic form of Creutzfeldt–Jakob disease (CJD) in 2012.

United States

In 1988, there was a confirmed death from CJD of a person from Manchester, New Hampshire. Massachusetts General Hospital believed the person acquired the disease from a surgical instrument at a podiatrist's office. In 2007, Michael Homer, former Vice President of Netscape, had been experiencing consistent memory problems which led to his diagnosis. In September 2013, another person in Manchester was posthumously determined to have died of the disease. The person had undergone brain surgery at Catholic Medical Center three months before his death, and a surgical probe used in the procedure was subsequently reused in other operations. Public health officials identified thirteen people at three hospitals who may have been exposed to the disease through the contaminated probe, but said the risk of anyone's contracting CJD is "extremely low". In January 2015, former speaker of the Utah House of Representatives Rebecca D. Lockhart died of the disease within a few weeks of diagnosis. John Carroll, former editor of The Baltimore Sun and Los Angeles Times, died of CJD in Kentucky in June 2015, after having been diagnosed in January. American actress Barbara Tarbuck (General Hospital, American Horror Story) died of the disease on December 26, 2016. José Baselga, clinical oncologist having headed the AstraZeneca Oncology division, died in Cerdanya, March 21, 2021, from CJD. In April 2024, two hunters from the same lodge were found to be afflicted with Sporadic CJD after eating deer meat infected with chronic wasting disease (CWD), suggesting a potential link between CWD and CJD.

Research

Diagnosis

  • In 2010, a team from New York described detection of PrPSc in sheep's blood, even when initially present at only one part in one hundred billion (10−11) in sheep's brain tissue. The method combines amplification with a novel technology called surround optical fiber immunoassay (SOFIA) and some specific antibodies against PrPSc. The technique allowed improved detection and testing time for PrPSc.
  • In 2014, a human study showed a nasal brushing method that can accurately detect PrP in the olfactory epithelial cells of people with CJD.

Treatment

  • Pentosan polysulphate (PPS) may slow the progression of the disease, and may have contributed to the longer than expected survival of the seven people studied. The CJD Therapy Advisory Group to the UK Health Departments advises that data are not sufficient to support claims that pentosan polysulphate is an effective treatment and suggests that further research in animal models is appropriate. A 2007 review of the treatment of 26 people with PPS finds no proof of efficacy because of the lack of accepted objective criteria, but it was unclear to the authors whether that was caused by PPS itself. In 2012 it was claimed that the lack of significant benefits has likely been caused because of the drug being administered very late in the disease in many patients.
  • Use of RNA interference to slow the progression of scrapie has been studied in mice. The RNA blocks production of the protein that the CJD process transforms into prions.
  • Both amphotericin B and doxorubicin have been investigated as treatments for CJD, but as yet there is no strong evidence that either drug is effective in stopping the disease. Further study has been taken with other medical drugs, but none are effective. However, anticonvulsants and anxiolytic agents, such as valproate or a benzodiazepine, may be administered to relieve associated symptoms.
  • Quinacrine, a medicine originally created for malaria, has been evaluated as a treatment for CJD. The efficacy of quinacrine was assessed in a rigorous clinical trial in the UK and the results were published in Lancet Neurology, and concluded that quinacrine had no measurable effect on the clinical course of CJD.
  • Astemizole, a medication approved for human use, has been found to have anti-prion activity and may lead to a treatment for Creutzfeldt–Jakob disease.
  • A monoclonal antibody (code name PRN100) targeting the prion protein (PrP) was given to six people with Creutzfeldt–Jakob disease in an early-stage clinical trial conducted from 2018 to 2022. The treatment appeared to be well-tolerated and was able to access the brain, where it might have helped to clear PrPC. While the treated patients still showed progressive neurological decline, and while none of them survived longer than expected from the normal course of the disease, the scientists at University College London who conducted the study see these early-stage results as encouraging and suggest to conduct a larger study, ideally at the earliest possible intervention.
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