Delusion

A delusion is a false belief based on incorrect inference about external reality that is firmly held despite what almost everyone else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary. The belief is not ordinarily accepted by other members of the person's culture or subculture (i.e., it is not an article of religious faith). When a false belief involves a value judgement, it is regarded as a delusion only when the judgement is so extreme as to defy credibility. Delusional conviction can sometimes be inferred from an overvalued idea (in which case the individual has an unreasonable belief or idea but does not hold it as firmly as is the case with a delusion).^[1][2][3]

This article focuses primarily on the types of delusion that are commonly induced by hallucinogens or other psychoactive substances, as opposed to the various categories that are listed within the DSM as occurring within people who suffer from psychiatric disorders such as schizophrenia. Although there are common themes between these two causes of delusion, the underlying circumstances are distinct enough that they are seemingly very different in their themes, behaviour, and frequency of occurrence.

Within the context of psychoactive substance usage, delusions can usually be broken out of when overwhelming evidence is provided to the contrary or when the person has sobered up enough to logically analyse the situation. It is exceedingly rare for hallucinogen induced delusions to persist into sobriety.

It is also worth noting that delusions can often spread between individuals in group settings.^[4] For example, if one person makes a verbal statement regarding a delusional belief they are currently holding while in the presence of other similarly intoxicated people, these other people may also begin to hold the same delusion. This can result in shared hallucinations and a general reinforcement of the level of conviction in which they are each holding the delusional belief.

Delusions are most commonly induced under the influence of heavy dosages of hallucinogenic compounds, such as psychedelics, deliriants, and dissociatives. However, they can also occur to a lesser extent under the influence of cannabinoids, stimulant psychosis, and sleep deprivation. They are most likely to occur during states of memory suppression and share common themes and elements with clinical schizophrenia.

Types

All delusions can be categorized by whether or not they are bizarre and whether or not they are mood-congruent. These various different types are described and documented below:

• Bizarre delusion: A delusion that is characteristically absurd and completely implausible. An example of a bizarre delusion could be the belief that aliens have removed the delusional person's brain.
• Non-bizarre delusion: A delusion that, though false, is at least theoretically plausible. An example of this could be the belief that the delusional person is currently under police surveillance.
• Mood-congruent delusion: A delusion with content consistent with either a depressive or manic state. For example, a depressed person may believe that a news anchor on television highly disapproves of them as a person or that the world is ending. However, a manic person might believe that they are a powerful deity, that they have special talents, a special higher purpose, or are a famous person.
• Mood-neutral delusion: A delusion that does not relate to the sufferer's emotional state. For example, a belief that an extra limb is growing out of the back of one's head would likely be neutral to a persons depression or mania.

Themes

In addition to these categories, delusions can be classified by their thematic content. Although delusions can have any theme, certain underlying themes are commonly found amongst different people. Some of the more common delusional themes which are induced by psychoactive substances are described and documented below:

Delusion of reference

Delusions of reference (also referred to as ideas of reference) are perhaps the most common type of delusion. This delusion typically entails the falsely held belief that an insignificant remark, event, coincidence, or object in the person's environment is either a reaction to the individual or has significant personal meaning relating directly back to their life.^[5][6]

In psychiatry, delusions of reference form part of the diagnostic criteria for illnesses such as schizophrenia, delusional disorder, bipolar disorder, and schizotypal personality disorder.^{[citation needed]} To a lesser extent, they can also be a symptom of paranoid personality disorder.^{[citation needed]} They can also be caused by intoxication, especially with hallucinogens or during stimulant psychosis.

A list of common examples of this type of delusion are described and documented below:

• Believing that everyone on a passing bus is talking about them.
• Believing that people on television or radio are talking about or talking directly to them.
• Believing that headlines or stories in newspapers are written especially for them.
• Believing that events (even world events) have been deliberately contrived for them, or have special personal significance for them.
• Believing that the lyrics of a song are specifically about them.
• Believing that the normal function of cell phones, computers, and other electronic devices are sending secret and significant messages that only they can understand or believe.
• Believing that objects or events are being set up deliberately to convey a special or particular meaning to themselves.
• Believing that the slightest careless movement on the part of another person has a significant and deliberate meaning.
• Believing that posts on social network websites or Internet blogs have hidden meanings pertaining to them.

Delusion of sobriety

A delusion of sobriety typically entails the falsely held belief that one is perfectly sober despite obvious evidence to the contrary such as severe cognitive impairment, significant motor control loss, and an inability to fully communicate with others.

Delusions of sobriety are the most common type of delusion experienced under the influence of GABAergic compounds such as alcohol and benzodiazepines.

Delusion of transcendence

Delusions of transcendence typically entail a falsely held belief that the person has "transcended into a higher plane of existence" or has discovered the secret to "transcending" and will be able to implement it just as soon as they sober up. Once this occurs, however, the supposed secret is found to be nonsensical, incorrect, or forgotten.

They are commonly experienced under the influence of heavy dosages of psychedelic compounds, particularly during states of high level geometry, memory suppression, and internal hallucinations.

Delusion of enlightenment

Delusions of enlightenment typically entail the sudden realization the person has suddenly become "enlightened" and has figured out or been shown the supposed answer or meaning to life, the universe and everything. This delusion may be accompanied with euphoria from the belief that one has learned the fundamental truth about life. During the experience, this answer is felt to be incredibly simplistic and self-evident but is usually immediately forgotten or realized to be nonsensical once the person has sufficiently sobered up.

Delusions of enlightenment are one of the most common type of delusion under the influence of short acting ego dissolution inducing hallucinogenic compounds such as DMT, nitrous oxide, and salvia.

Delusion of death

Delusions of death are the falsely held belief that the person is about to die, is currently dying, no longer exists, or has already died. This delusion seems to be a result of anxiety caused by misinterpreting the experience of the person losing their sense of self during states of high level ego dissolution. This type of delusion is usually very distressing for the person experiencing it.

Delusions of death are commonly experienced under the influence of heavy dosages psychedelic and dissociative compounds.

Delusion of guilt

Delusions of guilt are caused by unfounded and intense feelings of remorse or guilt that lead the person to conclude that one must have committed some sort of deeply unethical act. The supposed unethical act can range from something relatively mild such as the belief that the person has cheated on their partner or it can be something much more serious such as the belief that they have murdered their friends and family.

Delusions of guilt are commonly experienced under the influence of heavy dosages psychedelic and dissociative compounds.

Delusion of reality

Delusions of reality are the unfounded belief that something fictional such as the plot of a TV show, film, video game, or book is an actual real life event. This delusion may manifest as the perception that the fictional events are genuinely occurring in one's immediate vicinity, or simply that the media being portrayed is real. For example, one may have the sensation that fictional media is occurring around them, or may believe they are watching events occurring in real life, but elsewhere. This delusion seems to be a result of high level immersion intensification combining with memory suppression to create a state of mind in which somebody is highly engrossed in media while no longer having a functional long term memory that can recall the difference between reality and fiction.

Delusions of reality are commonly experienced under the influence of heavy dosages of dissociative and occasionally psychedelic compounds.

Delusion of unreality

Delusions of unreality are the unfounded belief that the person is currently inside of a video game, dream, or movie and therefore their current actions will not have any real life consequences. Depending on the person, this delusion can sometimes result in committing crimes or violent acts. It seems to be a result of intense derealization combined with disinhibition and memory suppression to create an altered state of mind in which somebody mistakes reality for a fictional hallucination.

Delusions of unreality are commonly experienced under the influence of heavy dosages of hallucinogens and occasionally during stimulant psychosis.

Delusion of grandeur

Delusions of grandeur are the unfounded belief that oneself or another person is or has become god-like, immortal, a visionary genius, or celebrity.^[7][8][9]

The delusion of having become godlike is often seemingly a result of high level ego inflation and mania. The experience of thinking that another person or the people around them have become godlike is commonly the result of those people being more sober than the delusional person. This causes the delusional person to misinterpret that the other person/people are somehow more capable than a normal human being, when in fact it is just the delusional person who has become comparatively less capable due to cognitive suppressions such as memory suppression.

Delusions of grandeur attributed to oneself more commonly occur during stimulant psychosis. However, delusions of grandiosity which are attributed to other people are most commonly experienced under the influence of heavy dosages of psychedelics.

Delusional Parasitosis

Delusional parasitosis, also known as Ekbom's syndrome,^[10] is a form of psychosis in which victims acquire a strong delusional belief that they are infested with parasites, whereas in reality no such parasites are present.

Sufferers may injure themselves in attempts to rid themselves of the "parasites." Some are able to induce the condition in others through suggestion, in which case the term folie à deux may be applicable.^[10] Nearly any marking upon the skin, or small object or particle found on the person or his clothing can be interpreted as evidence for the parasitic infestation, and sufferers commonly compulsively gather such "evidence" and then present it to medical professionals when seeking help.

In the context of psychoactive substances, it is particularly common during stimulant psychosis after prolonged chronic usage of cocaine.^[11]