Continuing Education Activity

A delusion is a fixed false belief based on an inaccurate interpretation of an external reality despite evidence to the contrary. The diagnosis of a delusional disorder is made when a person has one or more non-bizarre (situations that are not real but also not impossible) delusional thoughts for one month or more that cannot be explained by any other condition. An individual's cultural beliefs merit consideration before coming to the diagnosis. Cultural beliefs also impact the content of delusions. In patients with delusional disorder, delusions(s) do not impact the functionality and the patient's behavior is not overtly bizarre. This activity reviews the evaluation and management of delusional disorder and highlights the role of the interprofessional team in caring for affected patients.

Objectives:

• Describe the different types of delusions.
• Summarize the epidemiology of delusional disorder.
• Describe the evaluation of delusional disorder.
• Employ interprofessional team strategies for improving care coordination and communication to advance care for patients with delusional disorder and improve outcomes.

Introduction

A delusion is a fixed false belief based on an inaccurate interpretation of an external reality despite evidence to the contrary. The belief is not congruent with one’s culture or subculture, and almost everyone else knows it to be false.[1] The diagnosis of a delusional disorder occurs when a person has 1 or more non-bizarre (situations that can take place in real life, although not real but are possible) delusional thoughts for 1 month or more, that has no explanation by another physiological, substance-induced, medical condition, or any other mental health condition. An individual's cultural beliefs merit consideration before coming to a diagnosis. Cultural beliefs also impact the content of delusions. Other than the delusions, the functionality is not impacted, and the behavior is not obviously bizarre.

Some of the most frequently encountered types of delusions are:

1. Delusional jealousy: That one’s sexual partner is unfaithful.
2. Bizarre: A delusion involving a phenomenon that is impossible, not understandable, and unrelated to normal life.
3. Erotomanic: A delusion that another person, more frequently someone of higher status, is in love with the individual.
4. Grandiose: A conviction of great talent, discovery, inflated self-worth, power, knowledge, or a relationship with someone famous or a deity.
5. Persecutory: The central theme is being conspired against, attacked, harassed, and obstructed in the pursuit of long-term goals.
6. Somatic: These involve bodily functions and sensations.
7. Mixed: No single theme is prevalent.
8. Thought broadcasting: Delusion that one's thought is projected and perceived by others.
9. Thought insertion: A delusion that one's thoughts are not one's own but are inserted into one's mind by an external source or entity.

Etiology

Delusional disorder is relatively rare, has a later age of onset as compared to schizophrenia, and does not show a gender predominance. The patients are also relatively stable. The exact cause of the delusional disorder is unknown.[2] Many biological conditions, like substance use, medical conditions, and neurological conditions, can cause delusions. The delusional disorder involves the limbic system and basal ganglia in those with intact cortical functioning.[3] Hypersensitive persons and ego defense mechanisms like reaction formation, projection, and denial are some psychodynamic theories for delusional disorder. Social isolation, envy, distrust, suspicion, and low self-esteem are factors that, when intolerable, lead a person to seek an explanation and thus form a delusion as a solution.[2] Immigrants with language barriers, deaf and visually impaired persons, as well as the elderly, are special populations who are more vulnerable to delusions.

Epidemiology

The lifetime morbid risk of delusional disorder in the general population has been estimated to range from 0.05 to 0.1%, based on data from various sources, including case registries, case series, and population-based samples. According to the DSM-5, the lifetime prevalence of delusional disorder is about 0.02%.[3] The prevalence of the delusional disorder is much rarer than other conditions like schizophrenia, bipolar disorder, and other mood disorders; this may be in part due to underreporting of delusional disorder, as those with delusional disorder may not seek mental health attention unless forced by family or friends. The mean age of onset is about 40 years, with a range of 18 to 90 years. The persecutory and jealous type of delusion is more common in males, while the erotomanic variety is more common in females.

Pathophysiology

Overall functioning is typically better preserved than in many other psychiatric disorders. However, occupational performance may be significantly impaired, and social withdrawal can occur. A distinguishing feature is that individuals often appear psychologically intact and behave normally except when discussing the specific delusional belief.

• Persecutory type: This is 1 of the most common types of delusions, and patients can be anxious, irritable, aggressive, or even assaultive - some patients may be litigious.
• Jealous type: Also known as “ Othello syndrome,” this type is more common in males; it can sometimes correlate with suicidal or homicidal ideations, and hence safety is an important consideration in evaluation and management.[4]
• Erotomanic type: Also known as “ psychose passionelle,” this type of delusion involves a belief that a person, usually of higher stature, is in love with the patient.[5] These patients are usually socially withdrawn, dependent, sexually inhibited, with a poor level of social and/or occupational functioning. “Paradoxical conduct” is an important characteristic wherein all denials of affection are rationalized as affirmations.[6] Males with this type of delusion can be more aggressive.[7]
• Somatic type: Also called monosymptomatic hypochondriacal psychosis, and the reality impairment is severe. The patient is unarguably convinced of the severity of the symptoms. The most common type of somatic delusions is that of infestation, for example, with parasites, body dysmorphic delusions, and body odor or halitosis. These patients also have anxiety and nervousness.
• Grandiose type: Also known as megalomania, is characterized by increased self-importance.
• Mixed type: Patients have 2 or more delusional themes.
• Unspecified type: Sometimes, a predominant delusion cannot be identified. Capgras syndrome is a delusional syndrome where there is a belief that a known person has been replaced by an impostor.[1] Cotard syndrome is a condition in which a patient believes he has lost his possessions, status, and even bodily organs.[1]

Delusional disorder in the partner of an individual with the delusional disorder: This is also known as a shared psychotic disorder.

History and Physical

General description: Patients are usually well-nourished and appropriately groomed. It may seem odd, suspicious, or litigious. Patients seek an ally in the clinician, but it is important not to accept the delusion, as it eventually distorts the patient’s reality and leads to distrust.[3]

Mood: Mood is usually congruent with the delusion; for example, a grandiose patient may be euphoric, or a paranoid patient may be anxious. Mild depressive symptoms are present.[8]

Perceptions: Usually, no abnormal perceptions are present. Auditory hallucinations may be present in some.

Thought: This is the primary abnormality in delusional disorder. The delusions are not bizarre and are clear as well as systematic, for example, a cheating spouse, persecutory delusions. It is essential to assess the patient's beliefs before concluding that a belief is a delusion. Some patients are verbose and circumstantial when describing their delusions. Bizarre delusions are more likely correlate with schizophrenia.[3]

Cognition: Memory and cognition are usually intact, and patients are oriented unless there is a specific delusion about person, place, or time.

Impulse control: It is important to evaluate for suicidal or homicidal ideations and plans. If there is a history of aggression with adverse action, then hospitalization should be considered.

Insight and judgment: Most commonly, patients have no insight regarding their delusions. Judgment is assessable by a history of past behavior and future plan.

Evaluation

Although there is no set of labs required for a delusional disorder, like most other psychiatric disorders. Imaging or laboratory tests should be considered to rule out any organic causes. Substance-induced conditions should be ruled out by getting a urine drug screen. After an organic cause is ruled out, a clinical exam should be completed. A clinician would do an assessment and ask further questions about their delusions. During the assessment, a complete mental status exam should be done. Interviewing family members and friends should be considered because they can provide further details about the delusions and, more importantly, a timeline of the presenting symptoms.

Treatment / Management

The treatment of delusional disorder is difficult, considering the lack of insight. A good doctor-patient relationship is key to successful treatment. Treatment includes psychotherapy that establishes trust and builds a therapeutic alliance. A patient's history of medication compliance is the best guide to select appropriate antipsychotic medication. An antipsychotic should be started for a trial period of 6 weeks, after which there is an evaluation of the effectiveness of the medication. Start a low dose and titrate up as needed. Another drug from another class can be tried after 6 weeks if no benefit is noted from initial treatment.[9] Though not a primary indication, drugs like lithium, valproic acid, and carbamazepine can be considered as an adjunct treatment if monotherapy with antipsychotics fails. Treatment response is better when combining psychotherapy with psychopharmacology.

Differential Diagnosis

Differential diagnosis for delusional disorder includes the following:

1. Obsessive-compulsive disorder: A person who remains convinced that his/her obsessions and compulsions are true convictions should be given the diagnosis of obsessive-compulsive disorder with absent insight.
2. Schizophreniform and schizophrenia: This can be differentiated from delusional disorder by the presence of other symptoms of the active phase of schizophrenia.[10]
3. Delirium/major neurocognitive disorder: Can mimic delusional disorder, but is distinguished based on the chronology of symptoms.
4. Depression or bipolar disorder: Delusions occur with mood episodes. A delusional disorder is diagnosed only when the span of delusions exceeds the total duration of mood symptoms.

Prognosis

The prognosis of delusional disorder is better with treatment and medication compliance. Almost 50% of patients have a good response to medication; more than 20% report a decrease in symptoms, and less than 20% report minimal to no change. Delusional disorder is usually a chronic condition, but when properly treated. A good prognosis is also associated with higher social and occupational functioning, early onset before age 30 years, female sex, and a sudden onset of symptoms.[2]

Complications

The delusional disorder, if left untreated, might lead to depression, often as a consequence of difficulties associated with the delusions. Delusions also can lead to violence or legal issues; for instance, stalking or harassing the object of delusion could lead to arrest. Further, patients suffering from this disorder can become alienated from others, particularly if their delusions interfere with their social ties.

Deterrence and Patient Education

Patients with a delusional disorder may have their first encounter with a nurse practitioner or primary care physician. It is important to refer these patients to a mental health counselor or a psychiatrist because the management is complex. Many of these patients lack insight into their disorder and consequently refuse treatment. Therefore, education of the community and family counseling of those who are related to the patient are crucial steps in a holistic approach toward managing a patient suffering from delusional disorder.

Enhancing Healthcare Team Outcomes

Despite treatment, relapses are frequent. The biggest obstacle to treatment is treatment compliance. A mental health nurse should work with the team, follow up on these patients, and assist with the coordination and follow-up of care, as many eventually run into legal and work-related problems. An interprofessional team approach ultimately results in the best patient outcomes.

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References

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Disclosure: Shawn Joseph declares no relevant financial relationships with ineligible companies.

Disclosure: Waquar Siddiqui declares no relevant financial relationships with ineligible companies.