Delusions 788
Photo by: Erica Guilane-Nachez


A delusion is a belief that is clearly false and that indicates an abnormality in the affected person's content of thought. The false belief is not accounted for by the person's cultural or religious background or his or her level of intelligence. The key feature of a delusion is the degree to which the person is convinced that the belief is true. A person with a delusion will hold firmly to the belief regardless of evidence to the contrary. Delusions can be difficult to distinguish from overvalued ideas, which are unreasonable ideas that a person holds, but the affected person has at least some level of doubt as to its truthfulness. A person with a delusion is absolutely convinced that the delusion is real.

Delusions are a symptom of either a medical, neurological, or mental disorder. Delusions may be present in any of the following mental disorders:

Overvalued ideas may be present in anorexia nervosa , obsessive-compulsive disorder , body dysmorphic disorder , or hypochondriasis .


Delusions are categorized as either bizarre or non-bizarre and as either mood-congruent or mood-incongruent. A bizarre delusion is a delusion that is very strange and completely implausible for the person's culture; an example of a bizarre delusion would be that aliens have removed the affected person's brain . A non-bizarre delusion is one whose content is definitely mistaken, but is at least possible; an example may be that the affected person mistakenly believes that he or she is under constant police surveillance. A mood-congruent delusion is any delusion whose content is consistent with either a depressive or manic state; for example, a depressed person may believe that the world is ending, or a person in a manic state (a state in which the person feels compelled to take on new projects, has a lot of energy, and needs little sleep) believes that he or she has special talents or abilities, or is a famous person. A mood-incongruent delusion is any delusion whose content is not consistent with either a depressed or manic state or is mood-neutral. An example is a depressed person who believes that thoughts are being inserted into his or her mind from some outside force, person, or group of people, and these thoughts are not recognized as the person's own thoughts (called "thought insertion").

In addition to these categories, delusions are often categorized according to theme. Although delusions can have any theme, certain themes are more common. Some of the more common delusion themes are:

  • Delusion of control: This is a false belief that another person, group of people, or external force controls one's thoughts, feelings, impulses, or behavior. A person may describe, for instance, the experience that aliens actually make him or her move in certain ways and that the person affected has no control over the bodily movements. Thought broadcasting (the false belief that the affected person's thoughts are heard aloud), thought insertion, and thought withdrawal (the belief that an outside force, person, or group of people is removing or extracting a person's thoughts) are also examples of delusions of control.
  • Nihilistic delusion: A delusion whose theme centers on the nonexistence of self or parts of self, others, or the world. A person with this type of delusion may have the false belief that the world is ending.
  • Delusional jealousy (or delusion of infidelity): A person with this delusion falsely believes that his or her spouse or lover is having an affair. This delusion stems from pathological jealousy and the person often gathers "evidence" and confronts the spouse about the nonexistent affair.
  • Delusion of guilt or sin (or delusion of self-accusation): This is a false feeling of remorse or guilt of delusional intensity. A person may, for example, believe that he or she has committed some horrible crime and should be punished severely. Another example is a person who is convinced that he or she is responsible for some disaster (such as fire, flood, or earthquake) with which there can be no possible connection.
  • Delusion of mind being read: The false belief that other people can know one's thoughts. This is different from thought broadcasting in that the person does not believe that his or her thoughts are heard aloud.
  • Delusion of reference: The person falsely believes that insignificant remarks, events, or objects in one's environment have personal meaning or significance. For instance, a person may believe that he or she is receiving special messages from the news anchorperson on television. Usually the meaning assigned to these events is negative, but the "messages" can also have a grandiose quality.
  • Erotomania: A delusion in which one believes that another person, usually someone of higher status, is in love with him or her. It is common for individuals with this type of delusion to attempt to contact the other person (through phone calls, letters, gifts, and sometimes stalking).
  • Grandiose delusion: An individual exaggerates his or her sense of self-importance and is convinced that he or she has special powers, talents, or abilities. Sometimes, the individual may actually believe that he or she is a famous person (for example, a rock star or Christ). More commonly, a person with this delusion believes he or she has accomplished some great achievement for which they have not received sufficient recognition.
  • Persecutory delusions: These are the most common type of delusions and involve the theme of being followed, harassed, cheated, poisoned or drugged, conspired against, spied on, attacked, or obstructed in the pursuit of goals. Sometimes the delusion is isolated and fragmented (such as the false belief that co-workers are harassing), but sometimes are well-organized belief systems involving a complex set of delusions ("systematized delusions"). A person with a set of persecutory delusions may be believe, for example, that he or she is being followed by government organizations because the "persecuted" person has been falsely identified as a spy. These systems of beliefs can be so broad and complex that they can explain everything that happens to the person.
  • Religious delusion: Any delusion with a religious or spiritual content. These may be combined with other delusions, such as grandiose delusions (the belief that the affected person was chosen by God, for example), delusions of control, or delusions of guilt. Beliefs that would be considered normal for an individual's religious or cultural background are not delusions.
  • Somatic delusion: A delusion whose content pertains to bodily functioning, bodily sensations, or physical appearance. Usually the false belief is that the body is somehow diseased, abnormal, or changed. An example of a somatic delusion would be a person who believes that his or her body is infested with parasites.

Delusions of control, nihilistic delusions, and thought broadcasting, thought insertion, and thought withdrawal are usually considered bizarre delusions. Most persecutory, somatic, grandiose, and religious delusions, as well as most delusions of jealousy, delusions of mind being read, and delusions of guilt would be considered non-bizarre.

See also Hallucinations



American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th edition, text revised. Washington, DC: American Psychiatric Association, 2000.

Kaplan, Harold I., M.D., and Benjamin, J. Sadock, M.D. Kaplan and Sadock's Synopsis of Psychiatry: Behavioral Sciences, Clinical Psychiatry. 8th edition. Baltimore: Williams and Wilkins, 2002.


Leeser, Jaimie, and William O'Donohue. "What is a Delusion? Epistemological Dimensions." Journal of Abnormal Psychology 108 (1999): 687-694.

Jennifer Hahn, Ph.D.

User Contributions:


I can sympathize with you. My brother also suffers from persecutory delusions. He is taking medication under the care of a psychiatrist, and sees a psychologist monthly, but he does not like it. After about a year, he would stop taking his medications, saying he didn't need them, was misdiagnosed, among other reasons. This went on for a years until my sister-in-law threatened to leave him if he stopped taking them just one more time. The medication treatment worksabout 50% better than without it. He's able to go to work, and I told him to call me if he's having a difficult time, he calls me everyday. One Dr. told us to change the subject immediately. I tell him he's boring and they're not interested in him, then change the subject. Here are two books I'm looking into. And ask a psychologist for direction for you on how to deal with her. Good luck!!
my ex wife is currently suffering some type of delusion problem. She feels as if the world is ending and she and she alone has to figure out, through "signs god gives her in dreams", how to save the world. These tend to come at times of stress in her life. i am currently seeking sole custody after her telling me "you only live for our kids, and if i dont figure this out you will have nothing to live for." she needs help, but i dont know how to talk her into getting it. of course she believes she is the only one that understands everything, and refuses to talk to someone about a possible problem. any suggestions?
My twin daughters three years ago become delusional. They now are 37 years old. They said things about me that were untrue. I just recently realized what I now feel is the mental problem. I grew up with mental illness all my life. Just realized that this is the ailment my sister has. I always tried to reason with her but no more. Stress I beleive is a big factor. They will not let me see my grandchildren and this hurts, but I will continue to pray and to hope that this condition just is with me. They are angry with the enire family because no one sees what they see.
As Psychiatry is a medical belief-system, its claims are no more accurate than any religion. Say we have someone who is said to be delusional, and is later revealed to be real; this discredits the false beliefs of the doctors. Why feed information poison to the masses if not to confuse them away from reality? Are clairvoyants, geniuses, and highly creative artists delusional? Or are doctors censuring the public from dangerous, strong-willed individuals that slip away from mind control by the medical field?
I was wondering whether delusional disorders can occur as false memories? The case is where a patient has delusions of persecution occurring during a 2 year period in the patients history. There is no evidence of schizophrenia, Skitzoid Affective Disorder or Bipolar Disorder. The patient did not undergo any surgeries during the 2 year period or in the recent past. The patients delusions are not current i.e. patient is not currently persecuted, rather she was in the past. If so, is this a rare delusional disorder? If not, what other options are there for diagnosis? Cheers
Can anyone prove their observation is not real?
To indicate someone is delusional, some evidence must be brought contrary to their belief.
Can persecutory delusions be brought on by extreme guilt of a past incident that actually happened? I know someone who just recently began having delusions that his family has turned society against him and that people want him hurt or dead because of something he did when he was 13 or 14. He has had an evaluation i believe he was diagnosed with severe social anxiety he only receives talk therapy.

Comment about this article, ask questions, or add new information about this topic: