Delusional disorder differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Simrat Sarai, M.D. [2]

Overview

Delusional disorder must be differentiated from other diseases that cause delusions, such as substrate deficiency, neurodegenerative disorders, vascular disease, other CNS disorders, infectious diseases, vitamin deficiencies, metabolic disorders, endocrinopathies, medications, toxins, substances, and other mental disorders such as schizophrenia and mood disorders.^[1]^[2]^[3]

Differential Diagnosis

The cases of primary delusional disorder are uncommon. The occurrence of delusional thinking has many sources, mostly secondary to other conditions. Hence a practical principle is to detect or rule out other possible, usually more common causes of delusions, before arriving at the diagnosis.^[4]^[2] These include the following:

Substrate deficiency
Neurodegenerative disorders
Vascular disease
Other CNS disorders
Infectious diseases
Vitamin deficiencies
Metabolic disorders
Endocrinopathies
Medications
Toxins
Substances
Delusional disorder must be differentiated from other mental disorders such as:
- Delirium
- Dementia
- Substance-related disorders (intoxication, withdrawal, substance-induced psychotic disorder with delusion)
- Mood disorders with delusional symptoms (manic or depressive type)
- Schizophrenia
- Hypochondriasis
- Body dysmorphic disorder (BDD)
- Obsessive-compulsive disorder (OCD)
- Paranoid personality disorder
- Shared psychotic disorder

Medical conditions associated with development of delusions is shown below in a tabular form:^[5]


Medical Conditions	Examples

Substrate deficiency	Hypoglycemia* Cerebral hypoxia* causes of cerebral hypoxia include cardiac insufficiency, pulmonary insufficiency, and severe anemia.
Neurodegenerative disorders	Alzheimer disease Pick disease Huntington disease Parkinson Disease Basal ganglia calcification (Fahr disease) Multiple sclerosis Metachromatic leukodystrophy
Vascular disease	Atherosclerotic vascular disease, especially when associated with diffuse, temporoparietal, or subcortical lesions Hypertensive encephalopathy Subarachnoid hemorrhage Temporal arteritis
Infectious disease	Human immunodeficiency virus/acquired immune deficiency syndrome (AIDS) Opportunistic infections in AIDS Encephalitis lethargica Creutzfeldt-Jakob disease Syphilis Malaria Acute viral encephalitis
Other CNS disorders	Brain tumors, especially temporal lobe and deep hemispheric tumors Epilepsy, especially complex partial seizure disorder, temporal lobe epilepsy Stroke* Brain abscess* CNS infection (meningitis, encephalitis)* Interictal psychosis Head trauma (subdural hematoma)* Anoxic brain injury Fat embolism Landau Kleffner syndrome SSPE*
Vitamin deficiences	Vitamin B-12 deficiency Folate deficiency Thiamine deficiency Niacin deficiency
Metabolic disorder	Hypercalcemia Hyponatremia Hypoglycemia Uremia Hepatic encephalopathy Porphyria Electrolyte disturbanceΔ Hepatic failure Postpartum psychosis*
Endocrinopathies	Addison disease Cushing syndrome Hyperthyroidism or hypothyroidism Panhypopituitarism Hashimoto thyroiditis (Hashimoto encephalopathy) Thyroid storm* Antiphospholipid syndrome Hashimoto thyroiditis (Hashimoto encephalopathy)
Medications	Analgesics such as meperidine, pentazocine, indomethacin Adrenocorticotropic hormones Anabolic steroids such as testosterone, methyltestosterone Anticholinergics such as atropine, scopolamine Antidepressants such as bupropion, others if triggering a manic switch Antiepileptics such as zonisamide, other anticonvulsants at high doses antimalarial such as mefloquine, chloroquine Anti-parkinsonian drugs such as levodopa, selegiline, amantadine, pramipexole, bromocriptine Antivirals such as abacavir, efavirenz, nevirapine, acyclovir Cardiovascular drugs such as digoxin, disopyramide, propafenone, quinidine Corticosteroids such as prednisone, dexamethasone, etc Inhalants such as toluene, butane, gasoline Interferons such as interferon alfa-2a/2b Over-the-counter (OTC) such as dextromethorphan (DXM), diphenhydramine, some decongestants Cimetidine Antibiotics (eg, cephalosporins, penicillin), disulfiram
Toxins	Carbon monoxide Organophosphates Heavy metals (eg, arsenic, manganese, mercury, thallium)
Other	Systemic lupus erythematosus
Substances	Amphetamines Cannabinoids such as marijuana, synthetic cannabinoids (ie, “spice”), dronabinol Alcohol and sedatives/hypnotics such as alcohol (intoxication or withdrawal), barbiturates and benzodiazepines (particularly withdrawal) Cannabis Stimulants such as cocaine, amphetamine/methamphetamine, methylphenidate, certain diet pills, “bath salts” (MDPV, mephedrone), MDMA/ecstasy Hallucinogens such as LSD, PCP (phencyclidine), ketamine, psilocybin-containing mushrooms, mescaline, synthetic “designer drugs” (eg, 2-CB, “N-Bomb” [25I-NBOMe]) , salvia divinorum

Note1: CNS: central nervous syndrome; SSPE: subacute sclerosing panencephalitis; SLE: systemic lupus erythematosus.
Note2: * Life-threatening.
Note3: Δ Acute psychosis may be seen with hypocalcemia and hypomagnesemia. Hypo- or hypernatremia may cause encephalopathy with delirium.

Differential Diagnoses for delusional disorder (Adapted from Manschreck, 1996) ^[6]


Disorder	Delusions	Hallucinations	Awareness	Other features

Delusional disorder	Present	Occasional	Alert	Relatively free of psychopathology
Psychotic disorder due to a general medical condition, with delusion	Present	Present	May be impaired	Cognitive changes; perceptual changes;substance abuse history; impairment of functioning frequent
Substance-induced psychotic disorder	Present (can be bizarre)	Present	Acute:impaired,Chronic:may be alert	History of substance abuse; impaired functioning likely
Schizophrenia	Present (bizarre)	Present	Alert	Emotional changes, pervasive thought disorder; role impairment
Major depressive episode	Present (usually mood congruent)	May or may not present	Alert	Concerted changes in mood and neurovegetative features
Manic Episode	Present (usually mood congruent)	May or may not present	Alert	Concerted changes in mood, decreased need for sleep, energy, lack of inhibition
Obsessive–Compulsive disorder	Not present	Not present	Alert	Not psychotic; impaired functioning likely
Personality disorder	Not present	Not present	Alert	Not psychotic
Somatoform disorder	Not present	Not present	Alert	Not psychotic
Shared psychotic disorder	Present	Not present	Alert	Close associate has same delusions

References

↑ Sadock, Benjamin J., Harold I. Kaplan, and Virginia A. Sadock. Kaplan & Sadock’s synopsis of psychiatry : behavioral sciences/clinical psychiatry. Philadelphia: Wolter Kluwer/Lippincott Williams & Wilkins, 2007. Print.
↑ ^2.0 ^2.1 Manschreck TC, Petri M (1978). “The paranoid syndrome”. Lancet. 2 (8083): 251–3. PMID 79043.
↑ Manschreck, THEO C. “Delusional disorder and shared psychotic disorder.” Comprehensive textbook of psychiatry 1 (2000): 1243-64.
↑ Sadock, Benjamin J., Harold I. Kaplan, and Virginia A. Sadock. Kaplan & Sadock’s synopsis of psychiatry : behavioral sciences/clinical psychiatry. Philadelphia: Wolter Kluwer/Lippincott Williams & Wilkins, 2007. Print.
↑ Sadock, Benjamin J., Harold I. Kaplan, and Virginia A. Sadock. Kaplan & Sadock’s synopsis of psychiatry : behavioral sciences/clinical psychiatry. Philadelphia: Wolter Kluwer/Lippincott Williams & Wilkins, 2007. Print.
↑ Manschreck, THEO C. “Delusional disorder and shared psychotic disorder.” Comprehensive textbook of psychiatry 1 (2000): 1243-64.

Template:WikiDoc Sources

[1] Sadock, Benjamin J., Harold I. Kaplan, and Virginia A. Sadock. Kaplan & Sadock’s synopsis of psychiatry : behavioral sciences/clinical psychiatry. Philadelphia: Wolter Kluwer/Lippincott Williams & Wilkins, 2007. Print.

[pmid79043-2] 2.0 ^2.1 Manschreck TC, Petri M (1978). “The paranoid syndrome”. Lancet. 2 (8083): 251–3. PMID 79043.

[3] Manschreck, THEO C. “Delusional disorder and shared psychotic disorder.” Comprehensive textbook of psychiatry 1 (2000): 1243-64.

[4] Sadock, Benjamin J., Harold I. Kaplan, and Virginia A. Sadock. Kaplan & Sadock’s synopsis of psychiatry : behavioral sciences/clinical psychiatry. Philadelphia: Wolter Kluwer/Lippincott Williams & Wilkins, 2007. Print.

[5] Sadock, Benjamin J., Harold I. Kaplan, and Virginia A. Sadock. Kaplan & Sadock’s synopsis of psychiatry : behavioral sciences/clinical psychiatry. Philadelphia: Wolter Kluwer/Lippincott Williams & Wilkins, 2007. Print.

[6] Manschreck, THEO C. “Delusional disorder and shared psychotic disorder.” Comprehensive textbook of psychiatry 1 (2000): 1243-64.

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