Mohan Raj

MAHENDRAN (not his real name) was certain that something strange was going on for about a week. Initially he wasn’t sure what it was. Gradually, it became clearer. While travelling, he noticed many people were watching him and talking about him. He was certain that people were monitoring him.

At work, his e-mails and phone were being tapped. He wrote to his CEO. The officials investigated his complaint but found no evidence of it. Mahendran thought they were covering up.

The other day, two people followed him home. When Mahendran confronted them, they were annoyed and refuted his accusation.

He was convinced that a group had surrounded his house one night and was trying to blow it up. He alerted his family members but they did not believe him.

No matter how much his family members tried to reason with him, Mahendran held on to his beliefs. As he was constantly worrying about his enemies’ actions and his safety, his performance at work suffered.

Delusion is a false, fixed belief. It is held with such conviction that logical reasoning or providing evidence to the contrary will not be able to shake it.

Religious and cultural beliefs and superstitions are left out of this definition, as they don’t denote pathology.


Delusion could be simple and ill systematised. “Somebody is trying to harm me”: who the persecutors are, their motive, and modus are not known and not elaborated. Or, delusion could be elaborate and well systematised.

Here, there are multiple delusions and all are well connected with each other. There will be a delusional explanation or interpretation for everything. In the early stage of psychosis, delusions tend to be ill systematised.

As the illness progresses, the individual tries to make sense of all the abnormal experiences and develops well systematised delusions.

Primary delusions are those that occur in the absence of other symptoms in an apparently normal individual. Sudden delusional idea, a primary delusion, appears literally out of the blue.

For example, Mr. A was looking at the beach and suddenly it occurred to him that he was the one chosen to save the earth. Secondary delusions follow some other symptoms.

Mr. B has a delusion of being followed secondary to persistent auditory hallucinations discussing his activities like a running commentary.


Delusion of Reference: This is the most common delusion. The person believes that he is being watched and that people are talking about him (“Wherever I go, people stare at me”; “My neighbours talk about me all the time”).

At times, the person believes that there are references to him in the TV or in the newspaper (“They mentioned my activities in the nine pm news in a coded manner”). Delusion of reference can be associated with delusion of being followed and delusion of being under surveillance.

Delusion of Persecution: Here, the complaint usually is that people are trying to harm him. The persecutor, the motive and the manner in which they are persecuting may vary. The motive could also be a delusional explanation.

The description of the delusion can be coloured by social factors. For example, an engineering student might say, “Robots have taken over the Internet and are trying to kill me by sending electrical impulses through the net”. A farmer might say, “My brother-in-law has done black magic against me”. But both are essentially the same kind of delusion..

Delusion of Grandiosity: This may manifest as having supernatural ability or extraordinary talents.

This type commonly occurs in Mania (“I am the Prime Minister”; “I am the new avatar of Vishnu”; “God has chosen me to save the world”).

Delusion of Love: The patient may believe that a person (usually of higher status) is in love with them. Stalkers of celebrities have this delusion.

Delusion of Nihilism: A belief that body parts aren’t functioning properly and that the person is dying. It is seen in severe depression.

Delusion of Dysmorphophobia: A belief that body parts have changed in size, colour or appearance. They pester plastic surgeons with requests for repeated corrective surgeries.

Though the name implies fear, this delusion has nothing to do with phobia.

Delusion of Infidelity: A belief that one’s spouse is unfaithful. If it is present with many other symptoms, there is no doubt. If it is the only symptom, it becomes difficult to assess whether it is a delusion or real.

In delusional disorder, a single delusion can be present and behaviour disturbance may be limited only to that symptom.

All other spheres of life can be near normal. A person with only delusion of infidelity might be working normally in the office but might be having a chaotic life at home.

Delusion occurs in mental illnesses like Schizophrenia; Delusional disorder; Acute Psychosis; Psychosis induced by alcohol or substance; Mania; Severe depression with psychotic symptoms.


Pharmacotherapy (medicines) is the primary mode of treatment. Delusions and associated psychotic symptoms respond well to a group of medicines known as “antipsychotics”.

One medicine is chosed based on its side effect profile, the patient’s age, presence of the other illness or intake of other medicines and other such factors.

Antipsychotics block the dopamine receptors in two brain pathways called mesolimbic and mesocortical tracts. High turnover of dopamine in these tracts is associated with psychotic symptoms.

A mode of psychotherapy called “cognitive restructuring” is beneficial in those who are on concurrent pharmacotherapy.

Delusion signifies a pathological process. Like most illnesses, early treatment yields a better response.

Awareness about the symptoms helps the family members recognise the illness early and initiate treament.


This article was first published in The Hindu on 09 Oct 2005.

Author: Dr. Mohan Raj S