Psychosis, Medical Vs. Psychiatric

Basics

Description

Mental derangement involving hallucinations, delusions, or grossly disorganized behavior resulting in loss of contact with reality
  • Complex and poorly understood pathophysiology
  • An excess in dopaminergic signaling may be a contributing factor
  • Psychosis ranges from a relatively mild derangement to catatonia
  • CNS impairment leading to a psychotic presentation may be due to:
    • Neurologic disorders
    • Metabolic conditions
    • Toxins or drug effects
    • Infections
  • Higher risk for underlying psychiatric disorder:
    • Hallucinations and illusions incorporated into delusional system
    • Late adolescence/early adulthood
    • Normal orientation
  • Higher risk for underlying medical disorder:
    • Middle- to late-life presentation
    • Acute onset
    • History of substance abuse
    • No pre-existing psychiatric history
    • Absence of a family history of major mental illness
    • Presence of pre-existing medical disorders
    • Lower socioeconomic level
    • Recent memory loss
    • Disorientation or distractibility
    • Abnormal vital signs
    • Visual hallucinations:
      • Delirium
      • Dementia
      • Migraines
      • Dopamine agonist therapy (i.e., carbidopa)
      • Posterior cerebral infarcts
      • Narcolepsy

Etiology

  • Neurologic:
    • Head trauma
    • Space-occupying lesions
    • Cerebrovascular accident
    • Seizure disorders
    • Hydrocephalus
  • Neuropsychiatric disorders (Parkinson, Huntington, Alzheimer, Pick, Wilson disease)
  • Infectious:
    • Focal infections in the elderly (UTI, pneumonia)
    • HIV
    • Neurosyphilis
    • Encephalitis
    • Lyme disease: Neuroborreliosis
    • Parasites:
      • Cerebral malaria
      • Neurocysticercosis
      • Schistosomiasis
      • Toxoplasmosis
      • Trypanosomiasis
  • Metabolic:
    • Electrolyte imbalance
    • Hypoglycemia
    • Hypoxia
    • Porphyria
    • Withdrawal syndromes
  • Endocrine:
    • Thyroid disorders
    • Parathyroid disorders
    • Diabetes mellitus
    • Pituitary abnormalities
    • Adrenal abnormalities
  • End-organ failure:
    • Cardiac/respiratory
    • Renal
    • Hepatic
  • Nutritional deficiencies:
    • Pernicious anemia
    • Wernicke–Korsakoff syndrome
    • Pellagra
    • Pyridoxine deficiency
  • Autoimmune disorders:
    • Systemic lupus erythematosus
    • Sarcoidosis
    • Myasthenia gravis
    • Paraneoplastic syndromes
  • Demyelinating disease:
    • Multiple sclerosis
    • Leukodystrophies
  • Postoperative states:
    • Delirium
  • Intoxicants:
    • Alcohol
    • Benzodiazepines
    • Barbiturates
    • Stimulants (cocaine, amphetamines)
    • Hallucinogens
    • Opiates
    • Anticholinergic compounds
    • Inhalants
    • Cannabis/synthetic cannabinoids
  • Toxins:
    • Bromide
    • Carbon monoxide
    • Heavy metals
    • Organophosphates
  • Medication side effects:
    • Corticosteroids
    • Anticholinergics
    • Sedative-hypnotics
  • Psychiatric:
    • Antidepressants
    • Antipsychotics
    • Lithium carbonate
  • Antiparkinsonian drugs
  • Anticonvulsants
  • Antibiotics (quinolones, isoniazid)
  • Antihypertensive agents
  • Cardiac (digitalis, lidocaine, propranolol, procainamide)
  • Interferon
  • Muscle relaxants
  • Over-the-counter medications:
    • Pseudoephedrine
    • Antihistamines
  • Psychiatric:
    • Schizophrenia
    • Schizoaffective disorder
    • Delusional disorder
    • Bipolar disorder with psychotic features
    • Major depression with psychotic features
    • Stress reactions including posttraumatic stress disorder
    • Narcolepsy (hallucinations at edge of sleep/wake cycle)
    • Postpartum psychosis

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