Hallucination in the context of Sleep paralysis

"Enhanced interrogation techniques" or "enhanced interrogation" was a program of systematic torture of detainees by the Central Intelligence Agency (CIA), the Defense Intelligence Agency (DIA) and various components of the U.S. Armed Forces at remote sites around the world — including Abu Ghraib, Bagram, Guantanamo Bay, Rabat, Udon Thani, Vilnius, Bucharest and Stare Kiejkuty — authorized by officials of the George W. Bush administration. Methods used included beating, binding in contorted stress positions, hooding, subjection to deafening noise, sleep disruption, sleep deprivation to the point of hallucination, deprivation of food, drink, and medical care for wounds, as well as waterboarding, walling, sexual humiliation, rape, sexual assault, subjection to extreme heat or extreme cold, and confinement in small coffin-like boxes. A Guantanamo inmate's drawings of some of these tortures, to which he himself was subjected, were published in The New York Times. Some of these techniques fall under the category known as "white room torture". Several detainees endured medically unnecessary "rectal rehydration", "rectal fluid resuscitation", and "rectal feeding". In addition to brutalizing detainees, there were threats to their families such as threats to harm children, and threats to sexually abuse or to cut the throat of detainees' mothers.

The number of detainees subjected to these methods has never been authoritatively established, nor how many died as a result of the interrogation regime, though this number could be as high as 100. The CIA admits to waterboarding three people implicated in the September 11 attacks: Abu Zubaydah, Khalid Sheikh Mohammed, and Mohammed al-Qahtani. A Senate Intelligence Committee found photos of a waterboard surrounded by buckets of water at the Salt Pit prison, where the CIA had claimed that waterboarding was never used. Former guards and inmates at Guantánamo have said that deaths which the US military called suicides at the time, were in fact homicides under torture. No murder charges have been brought for these or for acknowledged torture-related homicides at Abu Ghraib and at Bagram.

Melancholia or melancholy (Ancient Greek: μελαγχολία, romanized: melancholía; from μέλαινα χολή, mélaina cholḗ, 'black bile') is a concept found throughout ancient, medieval, and premodern medicine in Europe that describes a condition characterized by markedly depressed mood, bodily complaints, and sometimes hallucinations and delusions. Besides a pathological condition, melancholy could also refer to a mood or temperament and at times it was even used as a description of the human condition in general.

Melancholy (or more precisely the 'black bile', from which melancholy derives its name) was regarded as one of the four temperaments matching the four humours. Until the 18th century, doctors and other scholars classified melancholic conditions as such by their perceived common cause – an excess of a notional fluid known as "black bile", which was commonly linked to the spleen. Hippocrates and other ancient physicians described melancholia as a distinct disease with mental and physical symptoms, including persistent fears and despondencies, poor appetite, abulia, sleeplessness, irritability, and agitation. Later, fixed delusions were added by Galen and other physicians to the list of symptoms. In the Middle Ages, the understanding of melancholia shifted to a religious perspective, with sadness seen as a vice and demonic possession, rather than somatic causes, as a potential cause of the disease.

Antipsychotics, previously known as neuroleptics and major tranquilizers, are a class of psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizophrenia but also in a range of other psychotic disorders. They are also the mainstay, together with mood stabilizers, in the treatment of bipolar disorder. Moreover, they are also used as adjuncts in the treatment of treatment-resistant major depressive disorder.

The use of antipsychotics may result in many unwanted side effects such as involuntary movement disorders, gynecomastia, impotence, weight gain and metabolic syndrome. Long-term use can produce adverse effects such as tardive dyskinesia, tardive dystonia, tardive akathisia, and brain tissue volume reduction.

Levitation or transvection, in the paranormal or religious context, is the claimed ability to raise a human body or other object into the air by mystical means.

While believed in some religious and New Age communities to occur due to supernatural, miraculous, psychic, or "energetic" phenomena, there is no scientific evidence of levitation occurring. Alleged cases of levitation can usually be explained by deception and fraud, such as trickery, illusion, and hallucination.

Cannabis (/ˈkænəbɪs/), commonly known as marijuana (/ˌmærəˈwɑːnə/), weed, pot, and ganja, among other names, is a non-chemically uniform psychoactive drug from the Cannabis plant. Native to Central or South Asia, cannabis has been used as a drug for both recreational and entheogenic purposes and in various traditional medicines for centuries. Tetrahydrocannabinol (THC) is the main psychoactive component of cannabis, which is one of the 483 known compounds in the plant, including at least 65 other cannabinoids, such as cannabidiol (CBD). Cannabis can be used by smoking, vaporizing, within food, or as an extract.

Cannabis has various mental and physical effects, which include euphoria, altered states of mind and sense of time, difficulty concentrating, impaired short-term memory, impaired body movement (balance and fine psychomotor control), relaxation, and an increase in appetite. Onset of effects is felt within minutes when smoked, but may take up to 90 minutes when eaten (as orally consumed drugs must be digested and absorbed). The effects last for two to six hours, depending on the amount used. At high doses, mental effects can include anxiety, delusions (including ideas of reference), hallucinations, panic, paranoia, and psychosis. There is a strong relation between cannabis use and the risk of psychosis, though the direction of causality is debated. Physical effects include increased heart rate, difficulty breathing, nausea, and behavioral problems in children whose mothers used cannabis during pregnancy; short-term side effects may also include dry mouth and red eyes. Long-term adverse effects may include addiction, decreased mental ability in those who started regular use as adolescents, heart disease, chronic coughing, susceptibility to respiratory infections, and cannabinoid hyperemesis syndrome.

Recreational drug use is the use of one or more psychoactive drugs to induce an altered state of consciousness, either for pleasure or for some other casual purpose or pastime. When a psychoactive drug enters the user's body, it induces an intoxicating effect. Recreational drugs are commonly divided into three categories: depressants (drugs that induce a feeling of relaxation and calmness), stimulants (drugs that induce a sense of energy and alertness), and hallucinogens (drugs that induce perceptual distortions such as hallucination).

In popular practice, recreational drug use is generally tolerated as a social behaviour, rather than perceived as the medical condition of self-medication. However, drug use and drug addiction are severely stigmatized everywhere in the world. Many people also use prescribed and controlled depressants such as opioids, opiates, and benzodiazepines. What controlled substances are considered generally unlawful to possess varies by country, but usually includes cannabis (though some areas have legalised cannabis use), cocaine, opioids, MDMA, amphetamine, methamphetamine, psychedelics, benzodiazepines, and barbiturates. As of 2015, it is estimated that about 5% of people worldwide aged 15 to 65 (158 million to 351 million) had used controlled drugs at least once.

Salvia divinorum (Latin: sage of the diviners; also called ska maría pastora, seer's sage, yerba de la pastora, magic mint or simply salvia) is a species of plant in the sage genus Salvia, known for its transient psychoactive properties when its leaves, or extracts made from the leaves, are administered by smoking, chewing, or drinking (as a tea). The leaves contain the potent compound salvinorin A and can induce a dissociative state and hallucinations.

Mazatec shamans have a long and continuous tradition of religious use of S. divinorum to facilitate visionary states of consciousness during spiritual healing sessions. A media panic in the Western world, especially in the United States c. 2007, centered on reports of video sharing of drug use on the internet, legal teenage use of the drug, as well as a teenage suicide in Delaware, despite it being "unclear" what role the drug played in the incident. S. divinorum is legal in some countries, including the U.S. at the federal level; however over half of U.S. states have passed laws criminalizing it.

Schizophrenia is a mental disorder characterized variously by hallucinations (typically, hearing voices), delusions, disorganized thinking or behavior, and flat or inappropriate affect. Symptoms develop gradually and typically begin during young adulthood and rarely resolve. 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 formal diagnosis, the described symptoms need to have been present for at least six months (according to the DSM-5) or one month (according to the ICD-11). Many people with schizophrenia have other mental disorders, especially mood, anxiety, and substance use disorders, as well as obsessive–compulsive disorder (OCD).

About 0.3% to 0.7% of people are diagnosed with schizophrenia during their lifetime. In 2017, there were an estimated 1.1 million new cases and in 2022 a total of 24 million cases globally. Males are more often affected and on average have an earlier onset than females. The causes of schizophrenia may include genetic and environmental factors. Genetic factors include a variety of common and rare genetic variants. Possible environmental factors include being raised in a city, childhood adversity, cannabis use during adolescence, infections, the age of a person's mother or father, and poor nutrition during pregnancy.

In psychopathology, psychosis is a condition in which one is unable to distinguish, in one's experience of life, between what is and is not real. Examples of psychotic symptoms are delusions, hallucinations, and disorganized or incoherent thoughts or speech. Psychosis is a description of a person's state or symptoms, rather than a particular mental illness, and it is not related to psychopathy (a personality construct characterized by impaired empathy and remorse, along with bold, disinhibited, and egocentric traits).

Common causes of chronic (i.e. ongoing or repeating) psychosis include schizophrenia or schizoaffective disorder, bipolar disorder, and brain damage (usually as a result of alcoholism). Acute (temporary) psychosis can also be caused by severe distress, sleep deprivation, sensory deprivation, some medications, and drug use (including alcohol, cannabis, hallucinogens, and stimulants). Acute psychosis is termed primary if it results from a psychiatric condition and secondary if it is caused by another medical condition or drugs. The diagnosis of a mental-health condition requires excluding other potential causes. Tests can be done to check whether psychosis is caused by central nervous system diseases, toxins, or other health problems.

Atropa bella-donna, commonly known as deadly nightshade or belladonna, is a toxic perennial herbaceous plant in the nightshade family Solanaceae, which also includes tomatoes, potatoes and eggplant. It is native to Europe and Western Asia, including Turkey, its distribution extending from England in the west to western Ukraine and the Iranian province of Gilan in the east. It is also naturalised or introduced in some parts of Canada, North Africa and the United States.

The foliage and berries are extremely toxic when ingested, containing tropane alkaloids. It can also be harmful to handle and/or touch these plants. These toxins include atropine, scopolamine, and hyoscyamine, which cause delirium and hallucinations, and are also used as pharmaceutical anticholinergics. Tropane alkaloids are of common occurrence not only in the Old World tribes Hyoscyameae (to which the genus Atropa belongs) and Mandragoreae, but also in the New World tribe Datureae—all of which belong to the subfamily Solanoideae of the plant family Solanaceae.

A delusion is a fixed belief that is not amenable to change in light of conflicting evidence. 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."

In visual perception, an optical illusion (also called a visual illusion) is an illusion caused by the visual system and characterized by a visual percept that arguably appears to differ from reality. Illusions come in a wide variety; their categorization is difficult because the underlying cause is often not clear but a classification proposed by Richard Gregory is useful as an orientation. According to that, there are three main classes: physical, physiological, and cognitive illusions, and in each class there are four kinds: Ambiguities, distortions, paradoxes, and fictions. A classical example for a physical distortion would be the apparent bending of a stick half immersed in water; an example for a physiological paradox is the motion aftereffect (where, despite movement, position remains unchanged). An example for a physiological fiction is an afterimage. Three typical cognitive distortions are the Ponzo, Poggendorff, and Müller-Lyer illusion. Cognitive visual illusions are the result of unconscious inferences and are perhaps those most widely known.

Pathological visual illusions arise from pathological changes in the physiological visual perception mechanisms causing the aforementioned types of illusions; they are discussed e.g. under visual hallucinations.

Hypnagogia is the transitional state from wakefulness to sleep, also defined as the waning state of consciousness during the onset of sleep. Its corresponding state is hypnopompia – sleep to wakefulness. Mental phenomena that may occur during this "threshold consciousness" include hallucinations, lucid dreaming, and sleep paralysis.

Mania (/meɪniːˈə/ MAIN-ee-yah; also known as manic syndrome) is a psychiatric behavioral syndrome defined as a state of abnormally elevated arousal, affect, and energy level. During a manic episode, an individual will experience rapidly changing emotions and moods, highly influenced by surrounding stimuli. Although mania is often conceived of as a "mirror image" to depression, the heightened mood can be dysphoric as well as euphoric. As the mania intensifies, irritability can be more pronounced and result in anxiety or anger.

The symptoms of mania include elevated mood (either euphoric or irritable), flight of ideas, pressure of speech, increased energy, decreased "need" and desire for sleep, and hyperactivity. They are most plainly evident in fully developed hypomanic states, however, in full-blown mania, these symptoms become progressively exacerbated. In severe manic episodes, these symptoms may even be obscured by other signs and symptoms characteristic of psychosis, such as delusions (it may include delusions of grandeur and paranoid delusions), hallucinations, fragmentation of behavior, and catatonia.

Encephalitis (US: /ɛnsɛfəlˈaɪtɪs/, UK: /ɛnkɛfəlˈaɪtɪs/) is inflammation of the brain. The severity can be variable with symptoms including reduction or alteration in consciousness, aphasia, headache, fever, confusion, a stiff neck, and vomiting. Complications may include seizures, hallucinations, trouble speaking, memory problems, and problems with hearing.

Causes of encephalitis include viruses such as herpes simplex virus and rabies virus as well as bacteria, fungi, or parasites. Other causes include autoimmune diseases and certain medications. In many cases the cause remains unknown. Risk factors include a weak immune system. Diagnosis is typically based on symptoms and supported by blood tests, medical imaging, and analysis of cerebrospinal fluid.

Insanity, madness, lunacy, and craziness are behaviors caused by certain abnormal mental or behavioral patterns. Insanity can manifest as violations of societal norms, including a person or persons becoming a danger to themselves or to other people. Conceptually, mental insanity also is associated with the biological phenomenon of contagion (that mental illness is infectious) as in the case of copycat suicides. In contemporary usage, the term insanity is an informal, un-scientific term denoting "mental instability"; thus, the term insanity defense is the legal definition of mental instability. In medicine, the general term psychosis is used to include the presence of delusions and/or hallucinations in a patient; and psychiatric illness is "psychopathology", not mental insanity.

In English, the word "sane" derives from the Latin adjective sanus, meaning "healthy". Juvenal's phrase mens sana in corpore sano is often translated to mean a "healthy mind in a healthy body". From this perspective, insanity can be considered as poor health of the mind, not necessarily of the brain as an organ (although that can affect mental health), but rather refers to defective function of mental processes such as reasoning. Another Latin phrase related to our current concept of sanity is compos mentis ("sound of mind"), and a euphemistic term for insanity is non compos mentis. In law, mens rea means having had criminal intent, or a guilty mind, when the act (actus reus) was committed.

In esotericism, astral projection (also known as astral travel, soul journey, soul wandering, spiritual journey, spiritual travel) is an intentional out-of-body experience (OBE) in which a subtle body, known as the astral body or body of light which consciousness functions separately through from the physical body, travels throughout the astral plane.

The idea of astral travel is ancient and occurs in multiple cultures. The term "astral projection" was coined and promoted by 19th-century Theosophists. It is sometimes associated with dreams and forms of meditation. Some individuals have reported perceptions similar to descriptions of astral projection that were induced through various hallucinogenic and hypnotic means (including self-hypnosis). There is no scientific evidence that there is a consciousness whose embodied functions are separate from normal neural activity or that one can consciously leave the body and make observations of the physical universe. As a result, astral projection has been characterized as pseudoscience.