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Visual hallucinations in psychosis is when a subject with psychosis endures visual experiences which occur in the absence of corresponding external stimulation of the eye in the awake state, in which the subjects do not feel like they have control over, with sufficient sense of reality to resemble a authentic visual perception. [1]
Approximately one-third of patients with a psychotic disorder experience visual hallucinations. [1] [1] The mechanism behind this is largely unknown. [1] This slows development of new theraputic approaches. [1]
Visual hallucinations in psychosis are reported to have physical properties similar to real perceptions. [2] They are often life-sized, detailed, and solid, and are projected into the external world. They typically appear anchored in external space, just beyond the reach of individuals, or further away. They can have three-dimensional shapes, with depth and shadows, and distinct edges. They can be colorful or in black and white and can be static or have movement. [3] [4] [5] [6] [7] [8] [9]
Visual hallucinations may be simple/non-formed visual hallucinations, or complex/formed visual hallucinations. [10]
Simple visual hallucinations without structure are known as phosphenes and those with geometric structure are known as photopsias. [11] These hallucinations are caused by irritation to the primary visual cortex (Brodmann's area 17). [12]
Sometimes, hallucinations are 'Lilliputian', i.e., patients experience visual hallucinations where there are miniature people, often undertaking unusual actions. Lilliputian hallucinations may be accompanied by wonder, rather than terror. [13] [14]
Most people have multiple VH types. [2] Complex VH were most prevalent, mainly consisting of people and animals, followed by simple, then geometric VH. Few patients experienced only simple VH.[ citation needed ]
The frequency of hallucinations varies widely from rare to frequent, as does duration (seconds to minutes). It is common that the visual hallucinations typically occurred daily, for afew minutes per episode. [15] The content of hallucinations varies as well. Preliminary research has found that most individuals had multiple types of visual hallucinations. [15] Scenes involving people and/or animals were the most common, followed by simple geometric images. [2]
Complex (formed) visual hallucinations are more common than Simple (non-formed) visual hallucinations. [6] [8] In contrast to hallucinations experienced in organic conditions, hallucinations experienced as symptoms of psychoses tend to be more frightening. An example of this would be hallucinations that have imagery of bugs, dogs, snakes, distorted faces. Visual hallucinations may also be present in those with Parkinson's, where visions of dead individuals can be present. In psychoses, this is relatively rare, although visions of God, angels, the devil, saints, and fairies are common. [7] [8] Individuals often report being surprised when hallucinations occur and are generally helpless to change or stop them. [5] In general, individuals believe that visions are experienced only by themselves. [5] [6]
V1's functional connection with other brain regions is reduced in psychotic patients who experience visual hallucinations. [1] . This contrasts with the expectation that V1 would be active during conscious visual perception. [1]
Two neurotransmitters are particularly important in visual hallucinations – serotonin and acetylcholine. They are concentrated in the visual thalamic nuclei and visual cortex. [13]
The similarity of visual hallucinations that stem from diverse conditions suggest a common pathway for visual hallucinations. Three pathophysiologic mechanisms are thought to explain this.
The first mechanism has to do with cortical centers responsible for visual processing. Irritation of visual association cortices (Brodmann's areas 18 and 19) cause complex visual hallucinations. [12] [16]
The second mechanism is deafferentation, the interruption or destruction of the afferent connections of nerve cells, of the visual system, caused by lesions, leading to the removal of normal inhibitory processes on cortical input to visual association areas, leading to complex hallucinations as a release phenomenon. [14] [16]
The DSM-V lists visual hallucinations as a primary diagnostic criterion for several psychotic disorders, including schizophrenia and schizoaffective disorder. [17] [18] Visual hallucinations can occur as a symptom of the above psychotic disorders in 24% to 72% of patients at some point in the course of their illness. [3] [19] [11]
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.
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.
Hallucination is a perception in the absence of an external stimulus that has the compelling sense of reality. They are distinguishable from several related phenomena, such as dreaming, which does not involve wakefulness; pseudohallucination, which does not mimic real perception, and is accurately perceived as unreal; illusion, which involves distorted or misinterpreted real perception; and mental imagery, which does not mimic real perception, and is under voluntary control. Hallucinations also differ from "delusional perceptions", in which a correctly sensed and interpreted stimulus is given some additional significance.
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.
Richard Bentall is a Professor of Clinical Psychology at the University of Sheffield in the UK.
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."
Stimulant psychosis is a mental disorder characterized by psychotic symptoms. It involves and typically occurs following an overdose or several day binge on psychostimulants, although it can occur in the course of stimulant therapy, particularly at higher doses. One study reported occurrences at regularly prescribed doses in approximately 0.1% of individuals within the first several weeks after starting amphetamine or methylphenidate therapy. Methamphetamine psychosis, or long-term effects of stimulant use in the brain, depend upon genetics and may persist for some time.
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.
Psychotic depression, also known as depressive psychosis, is a major depressive episode that is accompanied by psychotic symptoms. It can occur in the context of bipolar disorder or major depressive disorder. Psychotic depression can be difficult to distinguish from schizoaffective disorder, a diagnosis that requires the presence of psychotic symptoms for at least two weeks without any mood symptoms present. Unipolar psychotic depression requires that psychotic symptoms occur during severe depressive episodes, although residual psychotic symptoms may also be present in between episodes. Diagnosis using the DSM-5 involves meeting the criteria for a major depressive episode, along with the criteria for "mood-congruent or mood-incongruent psychotic features" specifier.
Paraphrenia is a mental disorder characterized by an organized system of paranoid delusions with or without hallucinations and without deterioration of intellect or personality.
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.
Schizophrenia is a neurodevelopmental disorder with no precise or single cause. Schizophrenia is thought to arise from multiple mechanisms and complex gene–environment interactions with vulnerability factors. Risk factors of schizophrenia have been identified and include genetic factors, environmental factors such as experiences in life and exposures in a person's environment, and also the function of a person's brain as it develops. The interactions of these risk factors are intricate, as numerous and diverse medical insults from conception to adulthood can be involved. Many theories have been proposed including the combination of genetic and environmental factors may lead to deficits in the neural circuits that affect sensory input and cognitive functions.
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.
Brief psychotic disorder—according to the classifications of mental disorders DSM-IV-TR and DSM-5—is a psychotic condition involving the sudden onset of at least one psychotic symptom lasting 1 day to 1 month, often accompanied by emotional turmoil. Remission of all symptoms is complete with patients returning to the previous level of functioning. It may follow a period of extreme stress including the loss of a loved one. Most patients with this condition under DSM-5 would be classified as having acute and transient psychotic disorders under ICD-10. Prior to DSM-IV, this condition was called "brief reactive psychosis." This condition may or may not be recurrent, and it should not be caused by another condition.
Substance-induced psychosis is a form of psychosis that is attributed to substance intoxication, withdrawal or recent consumption of psychoactive drugs. It is a psychosis that results from the effects of various substances, such as medicinal and nonmedicinal substances, legal and illegal drugs, chemicals, and plants. Various psychoactive substances have been implicated in causing or worsening psychosis in users.
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.
The relationship between religion and schizophrenia is of particular interest to psychiatrists because of the similarities between religious experiences and psychotic episodes. Religious experiences often involve reports of auditory and/or visual phenomena, which sounds seemingly similar to those with schizophrenia who also commonly report hallucinations and delusions. These symptoms may resemble the events found within a religious experience. However, the people who report these religious visual and audio hallucinations also claim to have not perceived them with their five senses, rather, they conclude these hallucinations were an entirely internal process.
Bouffée délirante (BD) is an acute and transient psychotic disorder. It is a uniquely French psychiatric diagnostic term with a long history in France and various French speaking nations: Caribbean, e.g., Haiti, Guadeloupe, Antilles and Francophone Africa. The term BD was originally coined and described by Valentin Magnan (1835–1916), fell into relative disuse and was later revived by Henri Ey (1900–1977).