Delusional disorder

Background

Delusions are fixed beliefs that are not amenable to change in light of conflicting evidence.

Delusional subtypes

• Ertomanic type: when the central theme of the delusion is that another person is in love with the individual
• Grandiose type: when the central theme of the delusion is the conviction of having some great (but unrecognized) talent or insight or having made some important discovery
• Jealous type: when the central theme of the individual’s delusion is that his or her spouse or lover is unfaithful
• Persecutory type: when the central theme of the delusion involves the individual’s belief that he or she is being conspired against, cheated, spied on, followed, poisoned or drugged, maliciously maligned, harassed, or obstructed in the pursuit of long-term goals
• Somatic type: when the central theme of the delusion involves bodily functions or sensations
• Mixed type: applies when no one delusional theme predominates
• Unspecified type: applies when the dominant delusional belief cannot be clearly determined or is not described in the specific types

Clinical Features

• A. The presence of one (or more) delusions with a duration of 1 month or longer.
• B. Criterion A for schizophrenia has never been met.
• C. Apart from the impact of the delusion(s) or its ramifications, functioning is not markedly impaired, and behavior is not obviously bizarre or odd.
• D. If manic or major depressive episodes have occurred, these have been brief relative to the duration of the delusional periods.
• E. The disturbance is not attributable to the physiological effects of a substance or an­other medical condition and is not better explained by another mental disorder, such as body dysmorphic disorder or obsessive-compulsive disorder.

Differential Diagnosis

Psychiatric Disorders with Psychotic Symptoms

• Acute psychosis
• Schizophrenia
• Schizoaffective disorder
• Delusional disorder
• Schizotypal personality disorder
• Schizoid personality disorder
• Bipolar disorder with psychotic features

Organic Causes

• Meningitis
• Encephalitis
• Thyroid (Main)
• Toxin ingestion
• Medication effect

Nonorganic Causes

• Obsessive-compulsive and related disorders
• Depressive and bipolar disorders

Evaluation

Rule out other organic causes including substance abuse, medication effect or other medical conditions. Consider emergency psychiatric evaluation in addition to medical evaluation.

General ED Psychiatric Workup

• Point-of-care glucose
• CBC
• Chem 7
• LFTs
• ECG (for toxicology evaluation)
• ASA level
• Tylenol level
• Urine toxicology screen/Blood toxicology screen
• EtOH
• Urine pregnancy/beta-hCG (if female of childbearing age)
• Consider:
  • Ammonia (see Hepatic encephalopathy)
  • TSH (hypo or hyperthyroidism may mimic mental illness)
  • CXR (for Tb screen or rule-out delirium in older patient)
  • UA (for rule-out delirium in older patients)
  • Head CT (to rule-out ICH in patients with AMS)
  • Lumbar puncture (to rule-out meningitis or encephalitis)

Management

Difficult to treat given limited insight, however individual outpatient psychotherapy recommended.

General ED Psychiatric Management

• Non-pharmacologic
  • Verbal de-escalation
  • Offer comforting items: blanket, meal, pillow, etc
  • Quiet room
  • Physical restraints (should administer medications if restraints used, as decreases restraint time)
• Pharmacologic: Goal is to calm patient without oversedation
  • No history of psychosis
    • Haloperidol 0.5mg-5mg +/- lorazepam 0.25-2mg (PO/IM/IV)
      • Consider adding benztropine 0.5-2mg or diphenhydramine 25-50mg (PO/IV/IM) (reduces dystonia or extrapyramidal reaction)
    • Consider risperidone 0.5-2mg PO or olanzapine 2.5-20mg (PO/IM/SL) or ziprasidone 10-20mg IM
  • Known or suspected underlying psychotic illness
    • Continue treatment with previous antipsychotic or
    • PO: olanzapine 5-10mg or risperidone 0.5-2mg +/- lorazepam: 0.5-2mg
    • IM: olanzapine 2.5-20mg or ziprasidone 10-20mg or
    • (PO/IM/IV) Haloperidol 0.5-5mg +/- lorazepam 0.5-2mg
      • Consider adding benztropine 0.5-2mg or diphenhydramine 25-50mg (PO/IV/IM) (reduces dystonia or extrapyramidal reaction)

Disposition

• Home with outpatient psychiatric services if stable, versus inpatient psychiatric admission if unstable

See Also

• Acute psychosis
• Schizophreniform disorder
• Schizophrenia
• Meningitis
• Encephalitis
• Schizoaffective disorder

References

Authors

Matin Shah, Ross Donaldson