Delusion | |
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Specialty | Psychiatry |
A delusion [a] is a false fixed belief that is not amenable to change in light of conflicting evidence. [2] As a pathology, it is distinct from a belief based on false or incomplete information, confabulation, dogma, illusion, hallucination, or some other misleading effects of perception, as individuals with those beliefs are able to change or readjust their beliefs upon reviewing the evidence. However:
"The distinction between a delusion and a strongly held idea is sometimes difficult to make and depends in part on the degree of conviction with which the belief is held despite clear or reasonable contradictory evidence regarding its veracity." [2]
Delusions have been found to occur in the context of many pathological states (both general physical and mental) and are of particular diagnostic importance in psychotic disorders including schizophrenia, paraphrenia, manic episodes of bipolar disorder, and psychotic depression.
Delusions are categorized into four different groups:
French psychiatry (which is influenced by psychoanalysis), however, also establishes a difference between "paranoid" (paranoïde) and "paranoiac" (paranoïaque) delusion. [6] [7] The paranoid delusion, observed in schizophrenia, is non-systematized and is characterized by a disorganized structure and confused speech and thoughts. [8] The paranoiac delusion, observed in paraphrenia, is highly systematized (which means it is very organized and clear) and is focused on a single theme.
In addition to these categories, delusions often manifest according to a consistent theme. Although delusions can have any theme, certain themes are more common. Some of the more common delusion themes are:
Grandiose delusions or delusions of grandeur are principally a subtype of delusional disorder but could possibly feature as a symptom of schizophrenia and manic episodes of bipolar disorder. [12] Grandiose delusions are characterized by fantastical beliefs that one is famous, omnipotent or otherwise very powerful. The delusions are generally fantastic, often with a supernatural, science-fictional, or religious bent. In colloquial usage, one who overestimates one's own abilities, talents, stature or situation is sometimes said to have "delusions of grandeur". This is generally due to excessive pride, rather than any actual delusions. Grandiose delusions or delusions of grandeur can also be associated with megalomania. [13]
Persecutory delusions are the most common type of delusions and involve the theme of being followed, harassed, cheated, poisoned or drugged, conspired against, spied on, attacked, or otherwise obstructed in the pursuit of goals. Persecutory delusions are a condition in which the affected person wrongly believes that they are being persecuted. Specifically, they have been defined as containing two central elements: [14] [ page needed ] The individual thinks that:
According to the DSM-IV-TR , persecutory delusions are the most common form of delusions in schizophrenia, where the person believes they are "being tormented, followed, sabotaged, tricked, spied on, or ridiculed". [15] In the DSM-IV-TR, persecutory delusions are the main feature of the persecutory type of delusional disorder. When the focus is to remedy some injustice by legal action, they are sometimes called "querulous paranoia". [16]
Explaining the causes of delusions continues to be challenging and several theories have been developed. [17] [18] One is the genetic or biological theory, which states that close relatives of people with delusional disorder are at increased risk of delusional traits. Another theory is the dysfunctional cognitive processing, which states that delusions may arise from distorted ways people have of explaining life to themselves. A third theory is called motivated or defensive delusions. This one states that some of those persons who are predisposed might experience the onset of delusional disorder in those moments when coping with life and maintaining high self-esteem becomes a significant challenge. In this case, the person views others as the cause of their personal difficulties in order to preserve a positive self-view. [19]
This condition is more common among people who have poor hearing or sight. Also, ongoing stressors have been associated with a higher possibility of developing delusions. Examples of such stressors are immigration, low socioeconomic status, and even possibly the accumulation of smaller daily struggles. [20]
The top two factors mainly concerned in the germination of delusions are disorder of brain functioning and background influences of temperament and personality. [21]
Higher levels of dopamine qualify as a sign of disorders of brain function. That they are needed to sustain certain delusions was examined by a preliminary study on delusional disorder (a psychotic syndrome) instigated to clarify if schizophrenia had a dopamine psychosis. [22] There were positive results - delusions of jealousy and persecution had different levels of dopamine metabolite HVA and homovanillyl alcohol (which may have been genetic). These can be only regarded as tentative results; the study called for future research with a larger population.
It is simplistic to say that a certain measure of dopamine will bring about a specific delusion. Studies show age [23] [24] and gender to be influential and it is most likely that HVA levels change during the life course of some syndromes. [25]
On the influence of personality, it has been said: "Jaspers considered there is a subtle change in personality due to the illness itself; and this creates the condition for the development of the delusional atmosphere in which the delusional intuition arises." [26]
Cultural factors have "a decisive influence in shaping delusions". [27] For example, delusions of guilt and punishment are frequent in a Western, Christian country like Austria, but not in Pakistan, where it is more likely persecution. [28] Similarly, in a series of case studies, delusions of guilt and punishment were found in Austrian patients with Parkinson's being treated with l-dopa, a dopamine agonist. [29]
The two-factor model of delusions posits that dysfunction in both belief formation systems and belief evaluation systems are necessary for delusions. Dysfunction in evaluations systems localized to the right lateral prefrontal cortex, regardless of delusion content, is supported by neuroimaging studies and is congruent with its role in conflict monitoring in healthy persons. Abnormal activation and reduced volume is seen in people with delusions, as well as in disorders associated with delusions such as frontotemporal dementia, psychosis and Lewy body dementia. Furthermore, lesions to this region are associated with "jumping to conclusions", damage to this region is associated with post-stroke delusions, and hypometabolism this region associated with caudate strokes presenting with delusions.[ citation needed ]
The aberrant salience model suggests that delusions are a result of people assigning excessive importance to irrelevant stimuli. In support of this hypothesis, regions normally associated with the salience network demonstrate reduced grey matter in people with delusions, and the neurotransmitter dopamine, which is widely implicated in salience processing, is also widely implicated in psychotic disorders.[ citation needed ]
Specific regions have been associated with specific types of delusions. The volume of the hippocampus and parahippocampus is related to paranoid delusions in Alzheimer's disease, and has been reported to be abnormal post mortem in one person with delusions. Capgras delusions have been associated with occipito-temporal damage and may be related to failure to elicit normal emotions or memories in response to faces. [30]
The modern definition and Jaspers' original criteria have been criticised, as counter-examples can be shown for every defining feature.
Studies on psychiatric patients show that delusions vary in intensity and conviction over time, which suggests that certainty and incorrigibility are not necessary components of a delusional belief. [31]
Delusions do not necessarily have to be false or 'incorrect inferences about external reality'. [32] Some religious or spiritual beliefs by their nature may not be falsifiable, and hence cannot be described as false or incorrect, no matter whether the person holding these beliefs was diagnosed as delusional or not. [33] In other situations the delusion may turn out to be true belief. [34] For example, in delusional jealousy, where a person believes that their partner is being unfaithful (and may even follow them into the bathroom believing them to be seeing their lover even during the briefest of partings), it may actually be true that the partner is having sexual relations with another person. In this case, the delusion does not cease to be a delusion because the content later turns out to be verified as true or the partner actually chose to engage in the behavior of which they were being accused.
In other cases, the belief may be mistakenly assumed to be false by a doctor or psychiatrist assessing it, just because it seems to be unlikely, bizarre or held with excessive conviction. Psychiatrists rarely have the time or resources to check the validity of a person's claims leading to some true beliefs to be erroneously classified as delusional. [35] This is known as the Martha Mitchell effect, after the wife of the attorney general who alleged that illegal activity was taking place in the White House. At the time, her claims were thought to be signs of mental illness, and only after the Watergate scandal broke was she proved right (and hence sane).
Similar factors have led to criticisms of Jaspers' definition of true delusions as being ultimately 'un-understandable'. Critics (such as R. D. Laing) have argued that this leads to the diagnosis of delusions being based on the subjective understanding of a particular psychiatrist, who may not have access to all the information that might make a belief otherwise interpretable. R. D. Laing's hypothesis has been applied to some forms of projective therapy to "fix" a delusional system so that it cannot be altered by the patient. Psychiatric researchers at Yale University, Ohio State University and the Community Mental Health Center of Middle Georgia have used novels and motion picture films as the focus. Texts, plots and cinematography are discussed and the delusions approached tangentially. [36] This use of fiction to decrease the malleability of a delusion was employed in a joint project by science-fiction author Philip Jose Farmer and Yale psychiatrist A. James Giannini. They wrote the novel Red Orc's Rage , which, recursively, deals with delusional adolescents who are treated with a form of projective therapy. In this novel's fictional setting other novels written by Farmer are discussed and the characters are symbolically integrated into the delusions of fictional patients. This particular novel was then applied to real-life clinical settings. [37]
Another difficulty with the diagnosis of delusions is that almost all of these features can be found in "normal" beliefs. Many religious beliefs hold exactly the same features, yet are not universally considered delusional. For instance, if a person was holding a true belief then they will of course persist with it. This can cause the disorder to be misdiagnosed by psychiatrists. These factors have led the psychiatrist Anthony David to note that "there is no acceptable (rather than accepted) definition of a delusion." [38] In practice, psychiatrists tend to diagnose a belief as delusional if it is either patently bizarre, causing significant distress, or excessively pre-occupying the patient, especially if the person is subsequently unswayed in belief by counter-evidence or reasonable arguments.
Joseph Pierre, M.D. states that one factor that helps differentiate delusions from other kinds of beliefs is that anomalous subjective experiences are often used to justify delusional beliefs. While idiosyncratic and self-referential content often make delusions impossible to share with others, [39] Pierre suggests that it may be more helpful to emphasize the level of conviction, preoccupation, and extension of a belief rather than the content of the belief when considering whether a belief is delusional. [40]
It is important to distinguish true delusions from other symptoms such as anxiety, fear, or paranoia. To diagnose delusions a mental state examination may be used. This test includes appearance, mood, affect, behavior, rate and continuity of speech, evidence of hallucinations or abnormal beliefs, thought content, orientation to time, place and person, attention and concentration, insight and judgment, as well as short-term memory. [41]
Johnson-Laird suggests that delusions may be viewed as the natural consequence of failure to distinguish conceptual relevance. That is, irrelevant information would be framed as disconnected experiences, then it is taken to be relevant in a manner that suggests false causal connections. Furthermore, relevant information would be ignored as counterexamples. [42]
Although non-specific concepts of madness have been around for several thousand years, the psychiatrist and philosopher Karl Jaspers was the first to define the four main criteria for a belief to be considered delusional in his 1913 book General Psychopathology. [43] These criteria are:
Furthermore, when beliefs involve value judgments, only those which cannot be proven true are considered delusions. For example: a man claiming that he flew into the Sun and flew back home. This would be considered a delusion, [46] unless he were speaking figuratively, or if the belief had a cultural or religious source. Only the first three criteria remain cornerstones of the current definition of a delusion in the DSM-5.
Robert Trivers writes that delusion is a discrepancy in relation to objective reality, but with a firm conviction in reality of delusional ideas, which is manifested in the "affective basis of delusion". [47]
Delusions and other positive symptoms of psychosis are often treated with antipsychotic medication, which exert a medium effect size according to meta-analytic evidence. [48] Cognitive behavioral therapy (CBT) improves delusions relative to control conditions according to a meta-analysis. [49] A meta-analysis of 43 studies reported that metacognitive training (MCT) reduces delusions at a medium to large effect size relative to control conditions. [50]
Some psychiatrists criticize the practice of defining one and the same belief as normal in one culture and pathological in another culture for cultural essentialism. They argue that it is not justified to assume that culture can be simplified to a few traceable, distinguishable and statistically quantifiable factors and that everything outside those factors must be biological since cultural influences are mixed, including not only parents and teachers but also peers, friends, and media, and the same cultural influence can have different effects depending on earlier cultural influences. Other critical psychiatrists argue that just because a person's belief is unshaken by one influence does not prove that it would remain unshaken by another. For example, a person whose beliefs are not changed by verbal correction from a psychiatrist, which is how delusion is usually diagnosed, may still change his or her mind when observing empirical evidence, only that psychiatrists rarely, if ever, present patients with such situations. [51] [52]
Anthropologist David Graeber has criticized psychiatry's assumption that an absurd belief goes from being delusional to "being there for a reason" merely because it is shared by many people by arguing that just as genetic pathogens like viruses can take advantage of an organism without benefitting said organism, memetic phenomena can spread while being harmful to societies, implying that entire societies can become ill. David Graeber argued that if somatic medicine did not have higher scientific standards than psychiatry's way of defining delusion, pandemics like the plague would have been considered to transubstantiate from an illness to "a phenomenon that benefits the people" as soon as it had spread to a sufficiently large portion of the population. It was argued by Graeber that since deinstitutionalisation made sales of psychiatric medication profitable by no longer needing to spend money on keeping the patients in mental hospitals, corrupt incentives for psychiatry to allege "needs" for treatments have increased (in particular with regard to medicines that are said to be needed in daily doses, not so much regarding devices that can be kept for longer periods of time) which may itself be a harmful memetic pandemic in society that leads to diagnosing and medication of criticisms of widespread beliefs that are actually absurd and harmful, making the absurd belief that is not labelled as an illness profitable anyway by attracting criticisms that are labelled as illnesses.[ citation needed ]
Psychosis is a condition of the mind or psyche that results in difficulties determining what is real and what is not real. Symptoms may include delusions and hallucinations, among other features. Additional symptoms are disorganized thinking and incoherent speech and behavior that is inappropriate for a given situation. There may also be sleep problems, social withdrawal, lack of motivation, and difficulties carrying out daily activities. Psychosis can have serious adverse outcomes.
Paranoia is an instinct or thought process that is believed to be heavily influenced by anxiety, suspicion, or fear, often to the point of delusion and irrationality. Paranoid thinking typically includes persecutory beliefs, or beliefs of conspiracy concerning a perceived threat towards oneself. Paranoia is distinct from phobias, which also involve irrational fear, but usually no blame.
Schizophrenia is a mental disorder characterized variously by hallucinations, delusions, disorganized thinking and behavior, and flat or inappropriate affect. Symptoms develop gradually and typically begin during young adulthood and are never resolved. There is no objective diagnostic test; diagnosis is based on observed behavior, a psychiatric history that includes the person's reported experiences, and reports of others familiar with the person. For a diagnosis of schizophrenia, the described symptoms need to have been present for at least six months or one month. Many people with schizophrenia have other mental disorders, especially mood disorders, anxiety disorders, and obsessive–compulsive disorder.
Schizoaffective disorder is a mental disorder characterized by symptoms of both schizophrenia (psychosis) and a mood disorder - either bipolar disorder or depression. The main diagnostic criterion is the presence of psychotic symptoms for at least two weeks without prominent mood symptoms. Common symptoms include hallucinations, delusions, disorganized speech and thinking, as well as mood episodes. Schizoaffective disorder can often be misdiagnosed when the correct diagnosis may be psychotic depression, bipolar I disorder, schizophreniform disorder, or schizophrenia. This is a problem as treatment and prognosis differ greatly for most of these diagnoses. Many people with schizoaffective disorder have other mental disorders including anxiety disorders.
Delusional disorder, traditionally synonymous with paranoia, is a mental illness in which a person has delusions, but with no accompanying prominent hallucinations, thought disorder, mood disorder, or significant flattening of affect. Delusions are a specific symptom of psychosis. Delusions can be bizarre or non-bizarre in content; non-bizarre delusions are fixed false beliefs that involve situations that could occur in real life, such as being harmed or poisoned. Apart from their delusion or delusions, people with delusional disorder may continue to socialize and function in a normal manner and their behavior does not necessarily seem odd. However, the preoccupation with delusional ideas can be disruptive to their overall lives.
A thought disorder (TD) is a disturbance in cognition which affects language, thought and communication. Psychiatric and psychological glossaries in 2015 and 2017 identified thought disorders as encompassing poverty of ideas, neologisms, paralogia, word salad, and delusions—all disturbances of thought content and form. Two specific terms have been suggested—content thought disorder (CTD) and formal thought disorder (FTD). CTD has been defined as a thought disturbance characterized by multiple fragmented delusions, and the term thought disorder is often used to refer to an FTD: a disruption of the form of thought. Also known as disorganized thinking, FTD results in disorganized speech and is recognized as a major feature of schizophrenia and other psychoses. Disorganized speech leads to an inference of disorganized thought. Thought disorders include derailment, pressured speech, poverty of speech, tangentiality, verbigeration, and thought blocking. One of the first known cases of thought disorders, or specifically OCD as it is known today, was in 1691. John Moore, who was a bishop, had a speech in front of Queen Mary II, about "religious melancholy."
Kurt Schneider was a German psychiatrist known largely for his writing on the diagnosis and understanding of schizophrenia, as well as personality disorders then known as psychopathic personalities.
The mental status examination (MSE) is an important part of the clinical assessment process in neurological and psychiatric practice. It is a structured way of observing and describing a patient's psychological functioning at a given point in time, under the domains of appearance, attitude, behavior, mood and affect, speech, thought process, thought content, perception, cognition, insight, and judgment. There are some minor variations in the subdivision of the MSE and the sequence and names of MSE domains.
Thought broadcasting is a type of delusional condition in which the affected person believes that others can hear their inner thoughts, despite a clear lack of evidence. The person may believe that either those nearby can perceive their thoughts or that they are being transmitted via mediums such as television, radio or the internet. Different people can experience thought broadcasting in different ways. Thought broadcasting is most commonly found among people who have a psychotic disorder, specifically schizophrenia.
An auditory hallucination, or paracusia, is a form of hallucination that involves perceiving sounds without auditory stimulus. While experiencing an auditory hallucination, the affected person hears a sound or sounds that did not come from the natural environment.
The classification of mental disorders, also known as psychiatric nosology or psychiatric taxonomy, is central to the practice of psychiatry and other mental health professions.
Grandiose delusions (GDs), also known as delusions of grandeur or expansive delusions, are a subtype of delusion characterized by the extraordinary belief that one is famous, omnipotent, wealthy, or otherwise very powerful or of a high status. Grandiose delusions often have a religious, science fictional, or supernatural theme. Examples include the extraordinary belief that one is a deity or celebrity, or that one possesses fantastical talents, accomplishments, or superpowers.
Folie à deux, also called shared psychosis or shared delusional disorder (SDD), is a psychiatric syndrome in which symptoms of a delusional belief are "transmitted" from one individual to another.
A persecutory delusion is a type of delusional condition in which the affected person believes that harm is going to occur to oneself by a persecutor, despite a clear lack of evidence. The person may believe that they are being targeted by an individual or a group of people. Persecution delusions are very diverse in terms of content and vary from the possible, although improbable, to the completely bizarre. The delusion can be found in various disorders, being more usual in psychotic disorders.
The word schizophrenia was coined by the Swiss psychiatrist Eugen Bleuler in 1908, and was intended to describe the separation of function between personality, thinking, memory, and perception. Bleuler introduced the term on 24 April 1908 in a lecture given at a psychiatric conference in Berlin and in a publication that same year. Bleuler later expanded his new disease concept into a monograph in 1911, which was finally translated into English in 1950.
A Truman Show delusion, also known as Truman syndrome or Truman disorder, is a type of delusion in which the person believes that their life is a staged reality show, or that they are being watched on cameras. The term was coined in 2008 on film boards by brothers Joel Gold and Ian Gold, a psychiatrist and a neurophilosopher, respectively, after the 1998 film The Truman Show.
Childhood schizophrenia is similar in characteristics of schizophrenia that develops at a later age, but has an onset before the age of 13 years, and is more difficult to diagnose. Schizophrenia is characterized by positive symptoms that can include hallucinations, delusions, and disorganized speech; negative symptoms, such as blunted affect and avolition and apathy, and a number of cognitive impairments. Differential diagnosis is problematic since several other neurodevelopmental disorders, including autism spectrum disorder, language disorder, and attention deficit hyperactivity disorder, also have signs and symptoms similar to childhood-onset schizophrenia.
The diagnosis of schizophrenia, a psychotic disorder, is based on criteria in either the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, or the World Health Organization's International Classification of Diseases (ICD). Clinical assessment of schizophrenia is carried out by a mental health professional based on observed behavior, reported experiences, and reports of others familiar with the person. Diagnosis is usually made by a psychiatrist. Associated symptoms occur along a continuum in the population and must reach a certain severity and level of impairment before a diagnosis is made. Schizophrenia has a prevalence rate of 0.3-0.7% in the United States.
A religious delusion is defined as a delusion, or fixed belief not amenable to change in light of conflicting evidence, involving religious themes or subject matter. Religious faith, meanwhile, is defined as a belief in a religious doctrine or higher power in the absence of evidence. Psychologists, scientists, and philosophers have debated the distinction between the two, which is subjective and cultural.
Schizophrenia is a primary psychotic disorder, whereas, bipolar disorder is a primary mood disorder which can also involve psychosis. Both schizophrenia and bipolar disorder are characterized as critical psychiatric disorders in the Diagnostic and Statistical Manual of Mental Disorders fifth edition (DSM-5). However, because of some similar symptoms, differentiating between the two can sometimes be difficult; indeed, there is an intermediate diagnosis termed schizoaffective disorder.