What Are the Most Common Delusions?

A delusion is a psychotic disorder where an individual has a fixed belief in an incorrect perception of reality. The most common delusions are:

• Persecutory Delusions
• Grandiose Delusions
• Jealous Delusions
• Erotomanic Delusions
• Somatic Delusions
• Mixed Delusions
• Unspecified Delusions

The risk of delusional disorder in the general population is estimated between 0.05% to 0.1% and affects individuals from the age of 18 years to 90 years [1].

The persecutory and jealous delusions are common in males, while the erotomanic delusions are more common in females.

1- What Is a Persecutory Delusion?

A persecutory delusion or paranoia delusion is a fixed belief of being persecuted, potentially harmed, or conspired against resulting in emotional and behavioral actions that can be extreme.

2- What Is a Grandiose Delusion?

A grandiose delusion is a fixed belief of being famous or having prominence, talent, and great achievements (Megalomania).

3- What Is a Jealous Delusion?

A jealous delusion or Othello syndrome is a fixed belief of being betrayed by the partner (unfaithful) and having evidence to support the delusion. This type of delusion can lead to extreme violence such as suicide and homicide.

4- What Is a Erotomanic Delusion?

An erotomanic delusion is a fixed belief of being secretly loved by an individual who may be known, or famous and outside the circle of the delusional individual.

This type of delusion is associated with intense expressions of love that can lead to stalking and assaultive behavior.

5- What Is a Somatic Delusion?

A somatic delusion is a fixed belief of individuals in having something wrong with their bodies, such as having an ugly body, an unknown disease, or being infected with parasites and insects, leading them to visit many doctors to determine their delusional illness.

6- What Is a Mixed Delusion?

A mixed delusion is when the affected individual has a combination of several types of delusions.

7- What Is an Unspecified Delusion?

This type of delusion cannot be classified according to the different types of delusions.

8- What Are the Signs of Delusions?

A delusional individual may manifest the following signs:

• Fixed and non-changeable belief in the delusion
• The individual is emotionally invested in the delusion
• The delusional individual is suspicious when questioned about the delusion
• Irritability and hostility if contradicted about the delusion
• Impact of the delusion on everyday life of the delusional individual

9- What Medical Conditions Can Cause Delusions?

Although the mechanisms are not known, they are several biological causes that may contribute to the development of a delusional disorder:

• Head injury
• Seizures
• Dementia
• Basal ganglia disorder (rare disease affecting the brain and other parts of the nervous system)
• Temporal lobe Disease (resulting in seizures)
• Unbalance in neurotransmission due to anomalies in the function of tyrosine hydroxylase involved in the synthesis of dopamine, epinephrine, and norepinephrine [2].

10- What Genetic Factors Cause Delusions?

Delusions appear to be more common in individuals with family members diagnosed with a delusion disorder or paranoid personality characteristics [3].

11-What Environmental Factors Cause Delusions?

Stress, drug, and alcohol abuse, and individuals’ social isolation, such as immigrants, appear to be contributing factors of delusions.

12- What Psychological Conditions Cause Delusions?

Although delusions have fewer symptoms and functional disability, they have been classified on the same spectrum as schizophrenia, and therefore, the neuropsychological models that are applied to schizophrenia are also applied to delusions [4].

• A cognitive bias model measures emotional and affective states of an individual in response to the individual perception and response to received information.
• A cognitive deficit model evaluates the impact of cognitive impairments on the formation of a delusion.

13- How Are Delusions Diagnosed?

The diagnosis of delusion may involve the use of the Peters et al. Delusions Inventory (PDI) that measures the delusional disorder of the individual through evaluating the ideas and concepts (ideation) behind the delusion using the Present State Examination [5].

Other tools that are used for the diagnosis of delusions involve questionnaires and interviews of the patient and immediate family about the everyday life of the patients and the potential existence of a history of mental health disorders, such as schizophrenia or mood disorders [6].

The assessment of the potential existence of physical disorders such as dementia, metabolic disorders, infections, and endocrine disorders (e.g., hormonal unbalance) is also performed through checking the patient medical record.

The questionnaires, interviews, and medical history records can help in eliminating potential psychological and physical disorders that might be involved in the etiology (cause) of the delusions.

14- How Are Delusions Treated?

The treatment of delusions may involve pharmacotherapy, cognitive-behavioral therapy (CBT), psychosocial interventions, and supportive psychotherapy. However, building a good doctor-patient relationship is the key to the success of the treatment [1].

• Pharmacotherapy

This treatment involves the use of psychotic medications, and antidepressants are used for somatic delusions.

• Cognitive Behavioral therapy (CBT)

Cognitive-behavioral therapy (CBT) focuses on identifying biases, worries, interpersonal sensitivity, reasoning style, and any factor that may have influenced the formation of the delusion (ideation) and what the delusional individual consider as evidence for the delusion.

The discussion and analysis that are performed during CBT therapeutic can help deconstruct the ideation that is at the heart of the delusional disorder [7].

• Supportive Therapy

Supportive Therapy aims at reducing the discomfort of the delusional individual through gaining insights about the individual experiences with the delusion and providing suggestions.

This therapeutic approach can also help the acceptance of the treatment process through educating the delusional individual about the illness [8].

Conclusion

Psychotic disorders are associated with individuals that have different perceptions of reality than those of most people around them. Delusions are also psychotic disorders characterized by a fixed and non-changeable interpretation of the reality which other people around them do not perceive.

The delusion is also a process that relies on building fixed ideas and concepts which explain the difficulty in treating delusional individuals. Therefore, achieving a successful treatment of a particular delusion would involve deconstructing those exact same ideas and concepts that make the delusion. However, building a good doctor-patient relationship is the key to the success of the treatment.