Delusion is a belief strongly held on to despite contrary evidence. Such belief is not backed by cultural, religious or social belief. It is a major feature of psychosis and schizophrenia. However, most people with delusion have intact psychosocial abilities (ability to interact with, perceive, influence and relate to others), as if the delusions are circumscribed. This is one of the key differences between delusional disorder and other primary psychotic disorder.

Delusion is a chronic disorder and many people who undergo treatment get relief from their delusions. However, many people with delusional disorders don’t have insight (they don’t belief they have a mental disorder), so they don’t seek medical attention. The lifetime morbid risk of delusional disorder in the general population has been estimated to range from 0.05 to 0.1 percent.

Types of delusional disorders

Various types of delusion exist and they include;

  • Persecutory delusion; the person believes that he/she is going to be harmed by an individual, a group of people or certain forces. This is the most common form of delusion in schizophrenia.
  • Delusion of Reference; belief that gestures, comments, or environmental cues are directed at oneself.
  • Grandiose delusion; the person has an over-inflated sense of worth, power, knowledge, or identity. The person might believe he or she has a great talent or has made an important discovery or has so much wealth and fame.
  • Nihilistic delusion; the person believes that a major disaster will occur.
  • Somatic delusion; this beliefs focuses on bodily function and parts. Usually, the false belief is that the body is somehow diseased, abnormal or changed. The person will complain of things crawling around the body even if after medical evaluation nothing is found.
  • Delusional jealousy: it’s a false belief that a spouse or lover is having an affair, with no proof to back up their claim.
  • Delusion of control: it’s the belief that another person, group of people, or external force controls one’s general thoughts, feelings, impulses, or behavior.
  • Erotomanic delusion; the individual has false belief that another individual is in love with them.
  • Delusion of thought insertion: Belief that another thinks through the mind of the person
  • Delusion of guilt or sin (or delusion of self-accusation): Ungrounded feeling of remorse or guilt of delusional intensity.
  • Cotard delusion; it’s the belief that one doesn’t exist or is dead.

 

Causes of delusion

The cause of delusional disorder is generally unknown. Certain theories have been associated with delusional disorders. They include;

  1. Genetic theory; which states that close relatives of people with delusional disorder are at increased risk of delusional traits.
  2. Motivated or defensive delusions theory; this states that some of those persons who are predisposed might suffer the onset of delusional disorder in those moments when coping with life’s challenges and maintaining high self-esteem becomes a significant challenge. In this case, the person views others as the cause of their personal difficulties in order to preserve a positive self-view.

Delusion is more common among people who have poor hearing or sight.

Ongoing stressors such as immigration, low socioeconomic status, and even possibly the accumulation of smaller daily hassles have been associated with a higher possibility of developing delusions.

Abnormal functioning of some parts of the brain has also been associated with delusional disorders.

 

Diagnosis

According to American Psychiatric Association patient should have any of the above delusions for one month or more before concluding on the diagnosis. Also other associated mental disorders like psychosis and schizophrenia must be ruled out.

It is important to differentiate delusion from an overvalued idea. A person with an overvalued idea can be talked out of that idea/belief unlike in delusion where the person can’t be talked out of it.

A proper review of the patient is done by the psychiatrist.

 Treatment

The management of delusion usually involves the use of both drugs and behavioral therapy (psychotherapy).

Medical treatment involves the use of anti-psychotics. Both the typical and atypical ones can be prescribed by the managing physician. The drugs work by blocking dopamine receptor alone (typical antipsychotics) or dopamine and serotonin (atypical antipschotics) receptors in the brain.  Some examples include; haloperidol, thorazinen and risperidone. These drugs have certain side effects thus follow up is very important.

Some people might be given antidepressants and tranquilizers to help with management of depression and anxiety disorder.

Behavioural therapy; this involves both the individual and the family. It is very important as it helps the individual to have a better understanding and acceptance of the problem while the family is encouraged to give the much desired support.