Delusions are considered inaccurate beliefs held by an individual, (typically with a mental illness), regardless of logical evidence disproving the belief. A delusion differs from a belief that is held based on insufficient information or perceptual feedback. An example of a non-deluded belief was when scientists initially thought that the Earth was the center of the solar system in the 4th century BCE.
As they gained new scientific insight into space with new technology (16th century), they updated their previously held false belief. Based on the accumulated scientific knowledge, we all now know that the Sun is in fact the center of the solar system. Someone that still believes [with conviction] that the Earth is the center of the solar system, despite significant evidence to the contrary, would be “deluded” in their thought.
Although a majority of delusions manifest as a result of excess dopaminergic activity, it is difficult to pinpoint the specific neurochemical abnormalities responsible for every delusion. In addition to positive symptoms of schizophrenia, delusions may occur in cases of psychotic depression, bipolar disorder, personality disorders, as well as those who abuse illicit drugs.
What are delusions?
In the earliest days of psychology, diagnostic criteria for delusions were developed by Karl Jaspers. Jaspers wrote an essay called “General Psychopathology” in 1910 that discussed delusions and various aspects of jealousy. He had specific criteria that included three key descriptors including: certainty (conviction), incorrigibility (unchangeable), and impossibility of content (implausible).
- Certainty: Individuals that hold delusions are certain in their beliefs; they believe with 100% conviction that they are real, despite significant logical evidence to the contrary.
- Incorrigibility: Those with delusions will not update their false beliefs even if presented with overwhelming logical evidence suggesting that the opposite is true. Despite scientific evidence to suggest that their way of thinking is flawed, they aren’t able to escape their deluded perception.
- Impossibility: The delusion that a person holds is not only untrue, but generally impossible or highly implausible to be true. Some of the delusions may not only seem like an obvious impossibility, but they may seem highly bizarre.
4 General Types of Delusions
There are many different, specific types of delusions that people may experience. According to the DSM-V, there are four specific classifications for delusions.
- Bizarre delusions: These types of delusions are considered extremely odd, highly implausible, and inappropriate based on the person’s culture and life experiences. An example of a bizarre delusion would be the belief that an alien performed surgery and replaced all of their blood with Kool-Aid without leaving a scar.
- Non-bizarre delusions: These are considered delusions that theoretically are possible, but still unlikely based on circumstances. An example of a non-bizarre delusion would be that an individual believes they are being secretly video-taped and phone-tapped by the F.B.I. as part of an investigation.
- Mood-congruent delusions: These are considered delusions that directly stem from a person’s mood (e.g. depression or mania). A person with severe depression may believe that strangers hate seeing him. A person with mania however may believe that they are a celebrity and should be recognized by TMZ or that by thinking happy thoughts, the sun will come out on a cloudy day.
- Mood-neutral delusions: A mood-neutral delusion is a false belief that isn’t directly related to a person’s emotional state. In other words, the delusion doesn’t stem from depressive or manic thoughts. An example of a mood-neutral delusion would be the false belief that your neighbor can project and insert thoughts into your head.
Specific Themes of Delusions
In addition to there being 4 general diagnostic types of delusions for a DSM-V diagnosis, there are also more specific themes of delusions. These themes range from: control (e.g. another person is able to control your brain) to grandeur (e.g. believing that you are God) to mind reading (e.g. others can read your mind). Some themes are more common than others.
Delusions of control: This is defined as a false belief that an external being, group, or energy is capable of controlling a person’s thoughts, ultimately influencing their emotions and behavior. Those experiencing delusions of control may believe that a group of people is forcing them to drive around the block three times, move their right arm up and down, or kick a fire hydrant.
- Thought broadcasting: This is the false belief that a person’s thoughts can be heard by others as if they are audible to everyone in their environment.
- Thought insertion: This is the false belief that others are inserting specific thoughts into the person’s head. A person may believe that they are being forced to think about the Mayan calendar by a religious group.
- Thought withdrawal: This is the false idea that people are able to intercept and remove a person’s thoughts. A person may believe that their thoughts are being “stolen” from their brain by others.
Capgras delusions: This is a type of delusion in which a person believes that someone they know (e.g. a family member or friend) has been replaced by an impostor with an identical appearance. This specific delusional theme often occurs among those that have been formally diagnosed with paranoid schizophrenia, dementia, or those that have endured a brain injury.
Clinical lycanthropy: This is another rare delusional theme in which a person believes they can morph from human into an animal. An example would be someone thinking that they were blessed with a special superhuman ability, allowing them to transform into a wolf. Keep in mind that this is one of the rarer delusional themes on this list.
Cotard delusions: These can be described as delusions in which a person believes they are already dead. A person with Cotard delusions may deny that they exist and some of these individuals may simultaneously experience delusions of immortality. “Cotard” delusions were named in honor of Jules Cotard, a neurologist who discovered this condition in the 1880s. The DSM does not include Cotard delusions in its specific diagnostic criteria.
Erotomania: Another delusional theme is that of erotomania in which an individual believes that a celebrity is in love with them. For example, a person may watch the Yankees and believe that Derek Jeter is their soulmate and sending signs of love only to them. Those with erotomania often attempt to contact the celebrity with gifts, letters, emails, and phone calls despite no reciprocation from the celebrity. In extreme cases, the individual may resort to becoming a stalker.
Fregoli delusions: These are considered extremely rare delusions in which a person believes that different people are all just a single person that is capable of morphing his/her appearance as a disguise. Some have speculated that these delusions are most associated with brain lesions or damage. If you experienced this delusion, you would think that everyone you see at the store is actually the same entity – just morphing into different people.
Delusions of guilt or sin (self-accusation): This type of delusions involve feeling guilty or remorseful for no valid reason. An example would be someone that believes they were responsible for a war in another country or hurricane damage in another state. In this case, the person believes that they deserve to be punished for their sins and place full blame on themselves. A person may see a crime on the news and believe that they were involved and to blame, despite the fact that they had never committed a crime.
Delusions of grandeur: Those experiencing grandiose delusions believe that they are a deity, have special powers (e.g. they can fly), rare abilities, or hidden talents. Some people with delusions of grandeur may believe that they are an incarnation of a god (e.g. Jesus Christ), a famous musician, or professional sports player. People experiencing this delusional theme believe that they should be praised for their talents and achievements, and therefore should be publically recognized.
Delusions of immortality: Some people may experience the delusion that they are immortal. Up to half of individuals experiencing Cotard delusions (the belief that they are already dead) also believe that they are immortal. Although this is a relatively uncommon delusional theme, it often occurs among individuals with nihilistic delusions.
Internet delusions: Since the boom of the internet in the 2000s, there have been delusional themes in which people believed they were being controlled by the Internet. As more individuals connect to the world-wide-web in coming years, expect the number of cases of internet-based delusions to increase. An example could be that someone believes that Google is controlling their brain and behaviors.
Delusions of jealousy: Those experiencing delusions of jealousy often believe that their significant other is having an affair, which leads to feelings of jealousy. Those that experience delusions of jealousy often have struggled with problems of preexisting pathological jealousy. Many people experiencing delusional jealousy repeatedly collect evidence in attempt to justify their delusions of infidelity. Eventually the individual with this delusion will confront their partner and present them with the accumulated “evidence” despite the fact that it shows nothing.
Delusions of mind being read: Some people experience false beliefs that another person or other people can read their mind and knows exactly what they’re thinking. This is different from delusions of control like thought broadcasting in that the individual doesn’t think that their thoughts are being perceived auditorily. An example could be that you walk into a library and think that the librarian can read your mind.
Nihilistic delusions: This is a false belief associated with the nonexistence of the “self,” specific body parts, or the world. Another variation of a nihilistic delusion could be that the self, body parts, and/or the world will be destroyed in the near future (e.g. the world will end). These are often considered synonymous with Cotard syndrome.
Delusions of persecution: Persecutory delusions occur when a person falsely believes they are being conspired against by others, sometimes in attempt to achieve a goal. An example would be if you thought your brother was trying to poison you by putting chemicals in your food that affected your ability to function at work.
Another example would be that the government is spying on them (e.g. tapping their phone lines) because they were wrongfully identified as a terrorist. Those with persecutory delusions often describe to others that all events they experience are in some way related to them being persecuted.
- Attacked: People wrongfully believe that others are blatantly attacking them as a person.
- Cheated: Some individuals believe that they are being cheated out of opportunities.
- Conspired against: Some people believe that their neighbors or work colleagues are conspiring to get them fired from their job or to get them to move out of state.
- Followed: It is very common for those with persecutory delusions to believe that they are being followed by other people (e.g. government spies).
- Harassment: Certain people believe that others are harassing them and/or going out of their way to make life difficult.
- Obstructed: Individuals think that others are trying to prevent them from achieving a certain goal.
- Poisoned: A specific type of a persecutory delusion that people experience is that of poisoning. They may believe that a restaurant chef has put a poisonous substance in their salad in attempt to make them sick.
- Spied upon: Other individuals believe that they are being spied upon by government officials (e.g. the C.I.A.).
Delusions of poverty: Some people believe that they are extremely poor and struggling financially, regardless of their current financial status. This isn’t quite as common of a delusion compared to others on this list, but it was more common in early days when those experiencing mental illness failed to get government aid.
Religious delusions: These are considered delusions that have a religious or spiritual basis. It is common for religious delusions to be connected to delusions of grandeur (e.g. a person believes they were “chosen” by a deity to become famous). These may also be connected to delusions of control (e.g. that a God is hearing their thoughts), and delusions of guilt or sin (e.g. that they should go to “Hell” for a tornado that occurred in Kansas). It should be noted that beliefs that are considered the norm for a particular religion or culture are not regarded as delusions.
Reduplicative paramnesia: Those with this delusional theme believe that a specific place or location has been replicated and exists in multiple locations simultaneously. Sometimes an individual with this delusional theme may believe that a place has been relocated or transferred to another place. This is a condition that is most often associated with brain injury.
Delusions of reference: An individual may believe that seemingly normal, insignificant events or occurrences have significant meaning. An example would be finding a penny on the ground and believing that it is a sign that the person is guaranteed to win the lottery. Another example would be watching a TV show and thinking that the host of the show has included specific messages just for them (e.g. seeing the color blue and believing it was preplanned because it’s the person’s favorite color).
Somatic delusions: A somatic delusion is a false belief that relates to a person’s body (functioning, sensations, etc.) and/or physical appearance. An example would be someone thinking that they are carrying a rare virus or that mites have burrowed under their skin and are eating their intestines.
Truman Show delusions: This is a delusional theme in which a person believes their entire life is staged on a reality show (e.g. The Truman Show). Those with the condition may experience a sense of grandiosity, but often times a simultaneous sense of persecution. This is another relatively rare delusional theme to experience, but one that has been documented.
How are themes of delusions classified?
The above delusional themes are classified based on one of the four types of delusions. The majority of the aforementioned themes fit into a theme of “bizarre” delusions or “non-bizarre” delusions. Should a person experience an emotional state as in bipolar disorder in which they are manic or depressive, and the delusion is related to their mood, it would be an example of a mood-congruent delusion. Delusions that aren’t related to any emotional state are considered mood-neutral.
- Delusions of control
- Nihilistic delusions
- Thought broadcasting
- Thought insertion
- Thought withdrawal
- Delusions of persecution
- Delusions of guilt or sin
- Delusions of grandeur
- Delusions of jealousy
- Delusions of mind being read
- Religious delusions
- Somatic delusions
Causes of Delusions (List)
It is often difficult to pinpoint the specific causes of delusions for every person. Some people may have a mental illness (e.g. schizophrenia) that causes the delusions, while others may experience delusions as a result of drug abuse. It is important to realize that two individuals may experience the same delusional themes, but the root cause may differ.
- Alcohol: Those that are heavy drinkers may be prone to experiencing delusions while intoxicated. Individuals that have struggled with alcoholism may experience delusions during alcohol withdrawal. Generally alcohol-induced delusions are temporary and subside as long as the individual completes a detoxification and remains sober.
- Bipolar disorder: There is evidence that those with bipolar disorder may be more susceptible to experiencing delusions than average. It is speculated that those with bipolar disorder are more likely to experience mood-congruent delusions or false beliefs directly related to their depressive or manic/hypomanic state.
- Brain injury: Research has demonstrated that individuals with brain injuries, particularly to the frontal lobe and right hemisphere is capable of causing delusions. Brain injuries can lead to cognitive impairment, which overtaxes the non-injured regions. This overcompensation among non-injured regions (particularly the left hemisphere) can be a direct cause of delusions.
- Bullying: While getting bullied doesn’t always cause delusions, those that get bullied experience profound changes in brain functioning if they are unable to cope. Extensive bullying causes changes in brain activity, which can lead to mental illness and in some cases, psychotic symptoms such as delusions. Children who are bullied are significantly more likely to experience delusions as teenagers than others. Kids that are bullied experience delusions at a two-fold rate compared to others.
- Cognitive impairment: Those who are cognitively impaired are also more likely to experience deluded thinking. Poor cognition can lead to dysfunctional and distorted perceptions of environment, circumstances, and the self, making delusions more likely to occur.
- Culture: Some cultures may be more likely to experience delusions than others. There is also evidence that certain cultures are more prone to specific delusional themes than others. In the West, people are more likely to experience delusions of guilt or sin, whereas in the Middle East, individuals are more likely to experience persecutory delusions.
- Depression: Those experiencing severe depression may become so depressed, that they experience delusions. When a person experiences delusions from depression, it may be related to neurochemical changes, a medication that the individual is taking, social isolation, and/or neurological changes as a result of long-term depression. Delusions are more common among those with psychotic forms of depression. In cases of depression, the delusions may have a depressive theme and thus be mood-congruent.
- Drugs: Many cases of drug-induced psychosis have been documented as a result of illicit stimulatory drug abuse (e.g. cocaine). While many delusions are experienced as a result of stimulant psychosis, delusions can also be experienced as a result of general drug-induced psychosis from non-stimulants like LSD. Delusions are also commonly experienced upon discontinuation of illicit drugs.
- Genetics: There is evidence that those with certain genetics are more prone to experiencing delusions than others. Those with close [first-degree] relatives that have been diagnosed with schizophrenia, delusional disorder, or have experienced delusions are more likely to experience delusions themselves. Exact genetics causing the delusions may differ based on the individual.
- HVA levels: There is some evidence that levels of HVA (a dopamine metabolite) may cause delusions in some individuals. Currently more research is warranted to back-up the initial findings that speculate HVA may be a causal factor. Compared to individuals without delusions, those with abnormal levels of HVA were more likely to experience delusions of persecution and jealousy.
- Social isolation: Those that isolate themselves from society for extended periods of time are more likely to experience delusions. Social isolation is capable of changing regional activity in the brain, activating/deactivating certain genes (epigenetics), and altering neurotransmission. Extensive social isolation alone may be a direct cause of delusions.
- Medications: Those that are taking pharmaceutical drugs, especially those that affect the brain are more likely to experience delusions. These pharmaceuticals alter neurotransmitter activity and receptor activation. Particularly those that are taking high doses of ADHD medications (like dopamine reuptake inhibitors) may experience delusions directly as a result of excess dopamine.
- Neurotransmitter dysfunction: Those that have a neurotransmitter or receptor imbalance may be more likely to experience delusions. It is thought that high levels of dopamine in certain brain regions may directly cause delusions. This is why individuals with excess dopamine are given antipsychotics to reduce dopamine levels, thus decreasing the delusions.
- Personality disorders: A preexisting personality disorder or temperament may make a person more likely to experience delusions. Environmental and genetic influences are thought to sculpt the personality, and may also make an individual more likely to experience delusions. Influence of a person’s personality is thought to be high in regards to causing delusions.
- Psychosis: Those that have experienced psychotic episodes, particularly those that were organic (e.g. non-drug induced) are likely to also experience delusions. Psychosis is commonly associated with schizophrenia and is thought to be a result of dopamine dysfunction and stemming from genetic abnormalities.
- Schizophrenia: People with schizophrenia are likely to experience delusions. Delusions are considered a hallmark positive symptom of this disease (the other being hallucinations). The specific types of delusions experienced may differ based on the specific type of schizophrenia.
- Sensory deficits: Those with delusions are thought to often have sensory deficits such as: poor hearing, poor vision, or a combination of both. Sensory deficits are known to alter brain functioning, perhaps in ways that make an individual more prone to delusions. The sensory deficits may also lead to excess stress, which is another influential factor.
- Stress: Excessive stress is known to cause delusions. Stress increases stimulatory neurotransmitters and may actually kill brain cells if we aren’t able to calm down. While a little stress every once in a while isn’t bad, harboring chronic stress and anxiety can alter the brain, making us more susceptible to deluded thinking.
- Trauma: Those that have been through a traumatic experience may end up dealing with delusions as a result. Trauma triggers off a high stress response and alters the way we think and our neurotransmission. Not being able to turn off the fight-or-flight response can lead to a cascade of changes such as sleep deprivation, poor diet, etc. – which influence delusions.
- Withdrawal: Those going through drug withdrawal may experience delusions. Particularly those that have taken a drug at high doses and are tapering too quickly may be more prone to delusions. It is also common for those that have taken drugs affecting dopamine levels to cause delusions upon withdrawal (e.g. Adderall withdrawal).
Treatment for Delusions
Not all cases of delusions require pharmaceutical treatment, some may just require an abstinence from illicit drugs. That said, many people benefit from taking medications to keep their delusions at bay, particularly those that are caused from a mental illness or neurotransmitter dysfunction.
- Antipsychotics: The most commonly administered treatment for delusions is that of antipsychotics. Atypical antipsychotics are generally preferred compared to older “typical” ones due to the fact that they are effective and have less severe side effects. Antipsychotics work by blocking dopamine receptors, thus inhibiting dopaminergic activity and decreasing delusions.
- Psychotherapy: In addition to antipsychotics, those suffering from delusions often benefit most from psychotherapy. This helps restructure their thinking and distinguish reality from their false perceptions. While therapy isn’t an overnight success, it is a great long-term option for those suffering from delusions. With therapy, individuals are able to learn various coping techniques and may be able to alter their behavioral responses when a delusional thought occurs.
Have you ever experienced delusions?
If you’ve ever experienced delusions, feel free to share your experience in the comments section below. Discuss the specific type of delusion(s) that you experienced as well as the more specific theme. To help others understand your situation, you may also want to include what you believe caused you to experience the delusion (e.g. mental illness, drug abuse, withdrawal, etc.).
Many people have experienced delusions at some point throughout their lives. Those that experience chronic delusions as is the case with schizophrenia often require pharmaceutical intervention to get them under control. How long did your delusional state last and how did you cope with the delusions?