Delusional disorder

Disease Description (Causes and Symptoms)

• Definition summary: Delusional disorder is a mental illness characterized by one or more persistent delusions lasting at least 1 month, representing a core impairment in reality testing, without prominent other features typical of schizophrenia, while everyday functioning is relatively preserved apart from the delusions.
• Main causes (unclear, but related factors)
  • Biological factors: Possible dysfunction of the dopamine system, focal brain lesions (such as in the limbic system or basal ganglia), and induction by medical conditions or medications/substances (drug intoxication or medication-induced causes).
  • Psychodynamic and psychosocial factors: Psychological defense mechanisms such as repression and projection; stress, isolation, immigration, and financial difficulties.
• Pathophysiology (summary): Although the exact pathophysiology is unclear, it is presumed that abnormalities in the dopamine system, functional abnormalities in specific brain regions (the limbic system and basal ganglia), and psychosocial vulnerability interact.
• Main symptoms
  • Persistent delusions that are not corrected by logical explanations (e.g., persecutory, jealous, grandiose, erotomanic, or somatic delusions)
  • Few thought disorders or marked disorganization of thought (such as auditory hallucinations) apart from the delusions
  • Lack of insight (awareness that one’s symptoms are pathological) is common
• Main types of delusions: Erotomanic type (believing that a celebrity or others love them), grandiose type, jealous type, persecutory type, somatic type, mixed type, and unspecified type

Treatment Methods

• General principles: Elimination of the cause (when possible) + antipsychotic medication treatment + psychosocial interventions
• Medication treatment
  • Second-generation antipsychotics (e.g., risperidone, olanzapine, aripiprazole) are used first. First-generation antipsychotics (e.g., haloperidol) may also be used depending on the situation.
  • Dosage and treatment duration are adjusted according to symptom severity, tolerability, and medical history. Because the treatment response may be delayed, sufficient observation time (several weeks to several months) is necessary.
  • Typical side effects: Weight gain, metabolic abnormalities, drowsiness, extrapyramidal symptoms, reduced motivation, etc. — regular monitoring is necessary.
• Psychotherapy and social interventions
  • Cognitive behavioral therapy (CBT for psychosis): Coping skills for delusions, stress management, reality-testing skills, etc.
  • Family therapy and education: Aims to reduce family conflict, ensure safety, and improve treatment adherence.
  • Social skills training and vocational rehabilitation can help maintain functioning.
• Indications for inpatient treatment
  • Risk of self-harm or harm to others, severe violent behavior, marked decline in daily functioning, or situations requiring protection for examination or treatment (including involuntary hospitalization)
• Lifestyle management and precautions
  • Avoid alcohol and substance abuse (risk of worsening symptoms)
  • Maintain regular sleep and manage stress; reduce social isolation
  • Monitor side effects when taking medication (sedation, metabolic effects, and movement symptoms) and undergo regular checkups (assessment of weight, blood glucose, lipids, and movement symptoms)
• Risk of complications
  • Violence (particularly with jealous or persecutory delusions), self-harm or suicide, social isolation and functional decline, and possible progression to other mental illnesses (schizophrenia or mood disorders)

Checklist Before an Outpatient Visit (Including Preparation Items and Example Questions)

• Preparation and information to organize in advance
  • A list of all medications currently being taken (including prescription and nonprescription medications, herbal medicines, and supplements)
  • Recent diagnoses and test results (such as brain imaging and blood tests), or copies if available
  • The onset and course of symptoms (when they began, duration, aggravating factors and relieving factors)
  • Specific examples of the delusional content (when and how the person acted) and records of risky behavior (violence, stalking, or suicide attempts)
  • Family history (psychiatric disorders and suicide), and history of alcohol or substance use
  • Records of changes in sleep patterns, eating, work, and social relationships
• Key information to tell the doctor first during the outpatient visit
  • Whether there has recently been violent behavior or suicidal thoughts
  • Medication intolerance or previous side effects
  • Level of ability to perform daily activities (whether the person can work and do household tasks)
• If testing is necessary
  • To distinguish medical causes, blood tests (including electrolytes, liver, kidney, thyroid, and drug screening tests), and, if necessary, brain imaging (MRI/CT), electroencephalography (EEG), etc., may be considered.
• Example questions (for patients and caregivers)
  • "When did the symptoms begin? Were they associated with any particular event?"
  • "Have you recently taken any drugs or experienced withdrawal symptoms?"

Examples of General Questions to Ask the Doctor

• How much benefit can be expected from this medication (or treatment), and how long will it take for the effect to appear?
• What are the main side effects of this medication, and how should I respond if side effects occur?
• In what situations is inpatient treatment necessary (such as safety risks or failure to respond to treatment)?
• If treatment fails, what are the next steps (other medications, long-term treatment, electroconvulsive therapy, etc.)?
• What is the prognosis? To what extent will it affect work and family life?

Examples of Disease-Specific Questions

• (Jealous delusions) We are concerned about the risk of violence or monitoring behavior toward the spouse. How can safety be ensured, and how should we respond legally and psychologically?
• (Somatic delusions) What physical examinations (such as dermatological examinations or infection tests) should be performed first to distinguish whether the physical symptoms are caused by delusions?

If additional information is needed, please provide the current symptoms (type and duration of the delusions), medications being taken, and whether there is a risk of self-harm or harm to others, and more specific guidance can be provided.