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Delusional Disorder

In delusional disorder, the patient suffers from 1 or more delusions for a duration of 1 month or more, without any other psychotic symptoms Psychotic symptoms Brief Psychotic Disorder or behavioral changes and no decline in functioning abilities. Diagnosis is clinical and the 1st-line treatment is antipsychotic Antipsychotic Antipsychotics, also called neuroleptics, are used to treat psychotic disorders and alleviate agitation, mania, and aggression. Antipsychotics are notable for their use in treating schizophrenia and bipolar disorder and are divided into 1st-generation antipsychotics (FGAs) and atypical or 2nd-generation antipsychotics. First-Generation Antipsychotics medications provided within the context of a trusting therapeutic relationship. Psychotherapy Psychotherapy Psychotherapy is interpersonal treatment based on the understanding of psychological principles and mechanisms of mental disease. The treatment approach is often individualized, depending on the psychiatric condition(s) or circumstance. Psychotherapy based on support and education may be helpful.

Last updated: Nov 14, 2022

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Definition and Epidemiology

Definition

Delusional disorder is characterized by unshakable false beliefs held by an individual despite being presented with rational, logical arguments and evidence to support the contrary. 

  • Not shared by the people of the same cultural or religious background
  • Cannot be accounted for by the individual’s level of intelligence 
  • The beliefs are typically difficult for others to understand.

Epidemiology

  • Lifetime prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency: 0.05%–0.1%
  • Men and women are affected equally often.
  • Mean age of onset is 40. 
  • Risk factors:
    • Family history Family History Adult Health Maintenance of schizophrenia Schizophrenia Schizophrenia is a chronic mental health disorder characterized by the presence of psychotic symptoms such as delusions or hallucinations. The signs and symptoms of schizophrenia are traditionally separated into 2 groups: positive (delusions, hallucinations, and disorganized speech or behavior) and negative (flat affect, avolition, anhedonia, poor attention, and alogia). Schizophrenia or schizotypal personality disorder Schizotypal Personality Disorder A personality disorder in which there are oddities of thought (magical thinking, paranoid ideation, suspiciousness), perception (illusions, depersonalization), speech (digressive, vague, overelaborate), and behavior (inappropriate affect in social interactions, frequently social isolation) that are not severe enough to characterize schizophrenia. Cluster A Personality Disorders
    • Sensory Sensory Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology impairment, especially hearing or vision Vision Ophthalmic Exam
    • Fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia
    • Emotional distress

Classification

Table: Different types of delusions with examples
Type Description Example
Delusions of persecution
  • Most common
  • The individual believes that they are going to be harmed by a living or nonliving thing.
“My office colleagues are ganging up against me since I am better than them. They want to belittle me in front of my boss.”
Delusions of grandeur The individual believes that they are very famous, rich, or talented. “The US president is my family friend.”
Delusions of guilt The individual believes that they are a bad person and have done something terribly wrong for which they deserve to be punished. “It is my fault that my dad is ill.”
Delusions of reference The individual misrepresents harmless, non-suspicious events or mere coincidences as being strongly applicable to them. “The news on TV is referencing me!”
Somatic delusions
  • The individual is preoccupied with their body and health.
  • They have false perceptions about their body.
“My nose Nose The nose is the human body’s primary organ of smell and functions as part of the upper respiratory system. The nose may be best known for inhaling oxygen and exhaling carbon dioxide, but it also contributes to other important functions, such as tasting. The anatomy of the nose can be divided into the external nose and the nasal cavity. Nose and Nasal Cavity: Anatomy is too big. My teeth Teeth Normally, an adult has 32 teeth: 16 maxillary and 16 mandibular. These teeth are divided into 4 quadrants with 8 teeth each. Each quadrant consists of 2 incisors (dentes incisivi), 1 canine (dens caninus), 2 premolars (dentes premolares), and 3 molars (dentes molares). Teeth are composed of enamel, dentin, and dental cement. Teeth: Anatomy are misshapen.”
Delusions of jealousy The individual believes that their spouse is being unfaithful based on inconspicuous bits of information. “I know my wife is having an affair with my best friend because I noticed that her clothes were wrinkled.”
Religious delusions
  • The individual believes that they are God, a saint, or an angel.
  • They are convinced they have spiritual powers or were born for a divine purpose.
“I am the next messiah!”
Erotomania or delusions of love The individual believes that someone is in love with them. “I am positively certain that Angelina Jolie loves me.”
Nihilistic delusions The individual believes that their body, or part of it, does not exist or that they are dead. “I am dead. I don’t have any lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs: Anatomy.”
Delusional memory Memory Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory. Psychiatric Assessment The individual clearly remembers events that did not occur. “On the evening of June 9, 2021, I was abducted from my home by aliens.”
Fantastic delusions The individual has bizarre delusions that follow no logic or common sense. “I’m slowly changing into a leopard.”

Diagnosis

Clinical diagnostic criteria

  • Presence of 1 or more delusions 
  • Duration of at least 1 month
  • The patient has never been diagnosed with schizophrenia Schizophrenia Schizophrenia is a chronic mental health disorder characterized by the presence of psychotic symptoms such as delusions or hallucinations. The signs and symptoms of schizophrenia are traditionally separated into 2 groups: positive (delusions, hallucinations, and disorganized speech or behavior) and negative (flat affect, avolition, anhedonia, poor attention, and alogia). Schizophrenia.
  • Note: Hallucinations Hallucinations Subjectively experienced sensations in the absence of an appropriate stimulus, but which are regarded by the individual as real. They may be of organic origin or associated with mental disorders. Schizophrenia might present in delusional disorder, but they are not prominent and only relate to the delusion theme.
  • No significant decline in daily functioning
  • Exclusion of other medical disorders ( OCD OCD Obsessive-compulsive disorder (OCD) is a condition characterized by obsessions (recurring and intrusive thoughts, urges, or images) and/or compulsions (repetitive actions the person is compelled to perform) that are time-consuming and associated with functional impairment. Obsessive-compulsive Disorder (OCD), body dysmorphic disorder Body dysmorphic disorder Body dysmorphic disorder (BDD) is a psychiatric disorder characterized by a patient’s preoccupation with minor or imagined flaws in their physical appearance. The obsession over the perceived defect leads to compulsive behaviors to cover it up, either with cosmetic therapy or social avoidance. Body Dysmorphic Disorder ( BDD BDD Body dysmorphic disorder (BDD) is a psychiatric disorder characterized by a patient’s preoccupation with minor or imagined flaws in their physical appearance. The obsession over the perceived defect leads to compulsive behaviors to cover it up, either with cosmetic therapy or social avoidance. Body Dysmorphic Disorder))
  • Exclusion of substance use or medications being the cause

Additional testing

  • Basic labs: complete metabolic panel
  • Urine toxicology for substance-induced psychosis Substance-induced psychosis Psychotic organic mental disorders resulting from the toxic effect of drugs and chemicals or other harmful substance. Brief Psychotic Disorder
  • Cranial CT or MRI

Management

General approach

  • It is difficult to initiate treatment, as patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship usually lack insight Insight Psychiatric Assessment and refuse medical treatment due to their delusion. 
  • Establish a good rapport, or a therapeutic relationship, before challenging the delusion.
  • Identify the psychosocial stressor that often triggers the delusion.
  • Psychotherapy Psychotherapy Psychotherapy is interpersonal treatment based on the understanding of psychological principles and mechanisms of mental disease. The treatment approach is often individualized, depending on the psychiatric condition(s) or circumstance. Psychotherapy based on support and education may be helpful.

Pharmacotherapy

The 1st-line pharmacologic treatment of delusional disorder is with 2nd-generation antipsychotic Antipsychotic Antipsychotics, also called neuroleptics, are used to treat psychotic disorders and alleviate agitation, mania, and aggression. Antipsychotics are notable for their use in treating schizophrenia and bipolar disorder and are divided into 1st-generation antipsychotics (FGAs) and atypical or 2nd-generation antipsychotics. First-Generation Antipsychotics medications. 

  • Most widely used substance: risperidone Risperidone A selective blocker of dopamine D2 receptors and serotonin 5-HT2 receptors that acts as an atypical antipsychotic agent. It has been shown to improve both positive and negative symptoms in the treatment of schizophrenia. Second-Generation Antipsychotics
  • Given for a short period of time
  • Discontinue if no benefits are observed after 6 weeks.

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

Delusional disorder usually has a good prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas, with 50% fully recovering and 20% showing significant remission Remission A spontaneous diminution or abatement of a disease over time, without formal treatment. Cluster Headaches.

Differential Diagnosis

  • Schizophrenia Schizophrenia Schizophrenia is a chronic mental health disorder characterized by the presence of psychotic symptoms such as delusions or hallucinations. The signs and symptoms of schizophrenia are traditionally separated into 2 groups: positive (delusions, hallucinations, and disorganized speech or behavior) and negative (flat affect, avolition, anhedonia, poor attention, and alogia). Schizophrenia: a chronic mental health disorder that is characterized by positive symptoms (delusions, hallucinations Hallucinations Subjectively experienced sensations in the absence of an appropriate stimulus, but which are regarded by the individual as real. They may be of organic origin or associated with mental disorders. Schizophrenia, disorganized speech or behavior) and negative symptoms (flat affect, avolition Avolition Lack of initiative. Schizophrenia, anhedonia Anhedonia Inability to experience pleasure due to impairment or dysfunction of normal psychological and neurobiological mechanisms. It is a symptom of many psychotic disorders (e.g., depressive disorder, major; and schizophrenia). Schizophrenia, poor attention Attention Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating. Psychiatric Assessment, and alogia Alogia Poverty of speech. Schizophrenia). The disorder is associated with a decline in functioning lasting over 6 months. The impairment of function due to the severity and duration of symptoms distinguishes schizophrenia Schizophrenia Schizophrenia is a chronic mental health disorder characterized by the presence of psychotic symptoms such as delusions or hallucinations. The signs and symptoms of schizophrenia are traditionally separated into 2 groups: positive (delusions, hallucinations, and disorganized speech or behavior) and negative (flat affect, avolition, anhedonia, poor attention, and alogia). Schizophrenia from delusional disorder.
  • Brief psychotic disorder Brief psychotic disorder Brief psychotic disorder is the presence of 1 or more psychotic symptoms lasting more than 1 day and less than 1 month. An episode is often stress-related with a sudden onset, and the patient fully returns to baseline functioning after an episode. Brief Psychotic Disorder: defined as the presence of 1 or more psychotic symptoms Psychotic symptoms Brief Psychotic Disorder lasting more than 1 day and less than 1 month. The disorder usually has a sudden onset and is often stress related. There is a full return to baseline functioning after the episode. Diagnosis is clinical, and treatment includes a brief course of 2nd-generation antipsychotics along with education and reassurance Reassurance Clinician–Patient Relationship. Unlike delusional disorder, brief psychotic disorder Brief psychotic disorder Brief psychotic disorder is the presence of 1 or more psychotic symptoms lasting more than 1 day and less than 1 month. An episode is often stress-related with a sudden onset, and the patient fully returns to baseline functioning after an episode. Brief Psychotic Disorder is characterized by impairment of function.

References

  1. Sadock, BJ, Sadock, VA, & Ruiz, P. (2014). Kaplan and Sadock’s synopsis of psychiatry: Behavioral sciences/clinical psychiatry (11th ed.). Chapter 7, Schizophrenia spectrum and other psychotic disorders, pp. 300–346. Philadelphia, PA: Lippincott Williams and Wilkins.
  2. Manschreck, T. (2020). Delusional disorder. UpToDate. Retrieved March 19, 2021, from https://www.uptodate.com/contents/delusional-disorder
  3. Joseph, SM, & Siddiqui, W. Delusional disorder. [Updated 2020 Nov 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. https://www.ncbi.nlm.nih.gov/books/NBK539855/

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