Updated: 4/2/2020

Delusional Disorder

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  • A 47-year old woman is arrested for trespassing the lawn of her neighbor, Mr. K, in the middle of the night. She states in an agitated tone that she wasn't trespassing because Mr. K "is in love with her" and "asked her to come over that night." Upon questioning the neighbor, Mr. K states that she has been bothering him for the last 6 weeks, but he thought she was just teasing him. On mental status exam, she is alert and oriented, but irritable. She denies auditory or visual hallucinations, but insists that Mr. K is the love of her life.  
  • Disorder characterized by > 1 month of delusions without other psychotic symptoms 
  • Delusions are:
    • false beliefs based on incorrect inference about reality 
    • typically non-bizarre
      • i.e., possible but highly unlikely
    • persist despite the evidence to the contrary 
    • beliefs are not ordinarily accepted by other members of the person's culture 
  • Functioning is otherwise unimpaired
  • Patient typically lack insight to the fact that their beliefs are delusions
  • Types of delusions:
    • persecutory -  belief one is going to be harmed
    • referential - belief that certain gestures, comments, or environmental cues are directed at oneself
    • grandiose - belief that the individual has exceptional abilities, wealth, or fame
    • nihilistic - conviction that a major catastrophe will occur
    • somatic - beliefs focused on bodily function or sensation
    • erotomanic - false belief that another individual is in love with them
  • Epidemiology
    • prevalence in USA is 0.02%
    • mean age of onset is 40 years 
    • F > M
  • Shared psychotic disorder (folie à deux)
    • development of delusions in a person in a close relationship with someone with delusional disorder
      • often resolves upon separation
    • in DSM V, "shared psychotic disorder" is NOT distinct from delusional disorder
  • Three steps in diagnosis:
    • ensure that true pathology is present (i.e., that the delusions are actually delusions)
    • assess for the presence of common characteristics associated with delusions (i.e., confusion, agitation, perceptual disturbances, prominent mood abnormalities)
    • conduct a systematic differential diagnosis (see below)
  • Delusional disorder criteria:
    • presence of one or more delusions for > 1 month
    • the criteria for schizophrenia has never been met before 
    • functioning is not markedly impaired
    • if manic or major depressive episodes have occurred, these have been brief relative to the duration of the delusional periods.
    • the disturbance is not better explained by another mental disorder (i.e., OCD) or organic disorder (i.e., ingestion)
  • Organic etiologies associated with delusions
    • neurodegenerative disorders 
    • infectious diseases (HIV, neurosyphillis, acute viral encephalitis)
    • metabolic (hypercalcemia, hyponatremia, hypoglycemia, uremia)
    • endocrinopathies (Addison's, Cushing's syndrome, hyperthyroidism)
    • vitamin deficiencies (cobalamine, folate, niacin, thiamine)
    • medications (corticosteroids, cimetidine, anticholinergics)
    • toxins (mercury, arsenic, manganese, thallium)
    • trauma (head)
  • Psychiatric diagnoses associated with delusions
    • delirium 
      • fluctuating level of consciousness, altered sleep/wake cycle, hallucinations and impaired cognition
    • dementia 
      • delusions present in up to 50% of dementia patients
    • substance-related
      • i.e., amphetamines, cocaine, alcohol, hallucinogens
    • schizophrenia
      • delusions of schizophrenia are bizarre in nature
      • disorganized thought process, speech, or behaviors are present
    • hypochondriasis
      • patients able to doubt (at least for a short while) their convictions of having illness when presented with reassuring data
    • body dysmorphic disorder 
      • obsessive focus on perceived flaw in appearance and excessive attempts to fix the flaw
      • significant overlap with delusional disorder
    • obsessive-compulsive disorder
      • patients often have insight into their obsessions and compulsions
    • paranoid personality disorder
      • difficult to differentiate between extreme characterological suspiciousness and frank delusions 
  • Difficult to treat due to patient denial and lack of insight
  • Psychotherapy
    • should consider CBT, insight-oriented therapy
  • Pharmacological
    • not standardized
    • evidence based on case-series and case reports
    • can consider atypical antipsychotics (olanzapine, risperidone) or antidepressants (SSRIs)

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Questions (1)
Lab Values
Blood, Plasma, Serum Reference Range
ALT 8-20 U/L
Amylase, serum 25-125 U/L
AST 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca2+) 8.4-10.2 mg/dL
Cholesterol, serum Rec: < 200 mg/dL
Cortisol, serum 0800 h: 5-23 μg/dL //1600 h:
3-15 μg/dL
2000 h: ≤ 50% of 0800 h
Creatine kinase, serum Male: 25-90 U/L
Female: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL
Electrolytes, serum  
Sodium (Na+) 136-145 mEq/L
Chloride (Cl-) 95-105 mEq/L
Potassium (K+) 3.5-5.0 mEq/L
Bicarbonate (HCO3-) 22-28 mEq/L
Magnesium (Mg2+) 1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)  
24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL
Ferritin, serum Male: 15-200 ng/mL
Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL
Female: premenopause: 4-30 mIU/mL
midcycle peak: 10-90 mIU/mL
postmenopause: 40-250
pH 7.35-7.45
PCO2 33-45 mmHg
PO2 75-105 mmHg
Glucose, serum Fasting: 70-110 mg/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative stimuli: > 7ng/mL
Immunoglobulins, serum  
IgA 76-390 mg/dL
IgE 0-380 IU/mL
IgG 650-1500 mg/dL
IgM 40-345 mg/dL
Iron 50-170 μg/dL
Lactate dehydrogenase, serum 45-90 U/L
Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL
Female: follicular phase: 5-30 mIU/mL
midcycle: 75-150 mIU/mL
postmenopause 30-200 mIU/mL
Osmolality, serum 275-295 mOsmol/kd H2O
Parathyroid hormone, serume, N-terminal 230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L
Phosphorus (inorganic), serum 3.0-4.5 mg/dL
Prolactin, serum (hPRL) < 20 ng/mL
Proteins, serum  
Total (recumbent) 6.0-7.8 g/dL
Albumin 3.5-5.5 g/dL
Globulin 2.3-3.5 g/dL
Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h
Thyroxine (T4), serum 5-12 μg/dL
Triglycerides, serum 35-160 mg/dL
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL
Triiodothyronine (T3) resin uptake 25%-35%
Urea nitrogen, serum 7-18 mg/dL
Uric acid, serum 3.0-8.2 mg/dL
Hematologic Reference Range
Bleeding time 2-7 minutes
Erythrocyte count Male: 4.3-5.9 million/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 12.0-16.0 g/dL
Hemoglobin, plasma 1-4 mg/dL
Leukocyte count and differential  
Leukocyte count 4,500-11,000/mm3
Segmented neutrophils 54%-62%
Bands 3%-5%
Eosinophils 1%-3%
Basophils 0%-0.75%
Lymphocytes 25%-33%
Monocytes 3%-7%
Mean corpuscular hemoglobin 25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration 31%-36% Hb/cell
Mean corpuscular volume 80-100 μm3
Partial thromboplastin time (activated) 25-40 seconds
Platelet count 150,000-400,000/mm3
Prothrombin time 11-15 seconds
Reticulocyte count 0.5%-1.5% of red cells
Thrombin time < 2 seconds deviation from control
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 19-31 mL/kg
Cerebrospinal Fluid Reference Range
Cell count 0-5/mm3
Chloride 118-132 mEq/L
Gamma globulin 3%-12% total proteins
Glucose 40-70 mg/dL
Pressure 70-180 mm H2O
Proteins, total < 40 mg/dL
Sweat Reference Range
Chloride 0-35 mmol/L
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 88-128 mL/min
Estriol, total (in pregnancy)  
30 wks 6-18 mg/24 h
35 wks 9-28 mg/24 h
40 wks 13-42 mg/24 h
17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 6-15 mg/24 h
Osmolality 50-1400 mOsmol/kg H2O
Oxalate 8-40 μg/mL
Potassium Varies with diet
Proteins, total < 150 mg/24 h
Sodium Varies with diet
Uric acid Varies with diet
Body Mass Index (BMI) Adult: 19-25 kg/m2

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