Understanding Delusions

Delusion is a symptom of many psychological disorders and a quite distressing one. In this blog, we’ll be discussing delusions and their most common types. 

What is a delusion?

A delusion is a false belief that is firmly held by an individual on inadequate grounds. It is a stringent belief that is false and it can indicate the deviancy or abnormality in the thought content of the experiencing person. Its key feature is the degree to which the individual is convinced that the belief is true. A delusional individual will hold the delusion firmly irrespective of the contrary evidence. An individual who believes that the Earth is triangular will keep on believing so even after you show them a globe or a picture of Earth taken from space. 

Sometimes delusions can be difficult to differentiate from overvalued ideas. However, the person who holds these overvalued ideas has some degree of doubt about their truthfulness. For example - A person who thinks that the Earth is triangular might be open to an alternate truth. He/She might believe that the Earth is round when they are shown its picture. In this case- the Earth is triangular is an overvalued idea. On the other hand, the person with a delusion is convinced that the delusion is real. They are not open to challenge it. 

Delusions are a common symptom of either a medical, neurological, or mental disorder. Delusions may be present in several disorders such as :

  1.  Psychotic disorders, or disorders in which the affected person has a diminished or distorted sense of reality. This includes schizophrenia, schizoaffective disorder, delusional disorder, schizophreniform disorder, shared psychotic disorder, brief psychotic disorder, and substance-induced psychotic disorder.
  2. Bipolar disorder 
  3. Major depressive disorder with psychotic features 
  4. Delirium
  5. Dementia

It is common for delusions to include a diverse range of false beliefs but their content frequently involves aspects of power, conspiracy, and magic. For example- a person who experiences delusions might believe that they are the secret rulers of the world, someone is always trying to kidnap them, and that angels are always surrounding them.

What are the most common types of delusions?

Based on one classification, delusions can be - bizarre, non-bizarre, mood-congruent, and mood-neutral. Bizarre delusions are those that are considered to be eccentric and very highly implausible. An example would be a belief that aliens have replaced their brain with the concerned person without any trace. Nonbizarre delusions include incidences that are possible but highly unlikely. It might be a belief that the person has been contacted by NASA to go to space. 

Mood-congruent delusions are very likely to be congruent or similar to the current mood of the experiencing individual. For example, an individual experiencing anxiety might believe that everything is difficult and so stressful and a person experiencing depression might believe that everyone does not want to talk to them.

Mood-neutral delusions, on the other hand, are not related to a person’s emotional state.

Within these broad categories, delusions typically fall under one of the following more specific categories:

  1. Persecutory delusions are beliefs that focus on the idea that one is being targeted, persecuted, or harassed by another individual or group. An example of a persecutory delusion would be the belief that one is being plotted against by the government.

  2. Somatic delusions involve preoccupations with physical experience, health, and organ function. An example of a somatic delusion is the belief that the lungs of an individual are working partially.

  3. Delusions of control are beliefs that other people are capable of controlling one’s mind, thoughts, or actions. A person with this delusion might believe that their thoughts and actions are controlled by someone else.

  4. Referential delusions are beliefs that neutral or general stimuli are referencing a specific individual, such as the idea that a TV newscaster is sending secret messages directly to an individual through their newscast.

  5. Religious delusions are beliefs that have a religious or spiritual theme. For example, an individual might believe that they were the chosen one in a clan to remove poverty from their country. It is important to remember that the religious beliefs considered within the norm for a particular religion or culture are not considered to be delusions.

  6. Grandiose delusions are beliefs that one has exceptional powers or abilities. A person with grandiose delusion might believe that they have the power to make objects fly or talk to animals.

  7. Nihilistic delusions are centered around the idea of the destruction of self, a body part, or even the world. An example might be the belief that the world will be destroyed within the next few days.

  8. An erotomanic delusion is a person’s conviction that another individual is in love with them.

  9. A Truman Show delusion is one of the rarer forms of delusion which is the belief that one’s life has been staged around a TV show (such as in the movie The Truman Show).


While delusions are a fascinating concept in psychology they are often misunderstood due to the lack of awareness. Beliefs are highly cultural and societal based and what might be delusional in one culture might be completely normalized in the other. The exact causes of a delusional disorder are unknown and there is no way to prevent it, however. Early diagnosis and treatment can minimize the impact on the individuals’ life.


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