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  • Author: Kannayiram Alagiakrishnan, MD, MBBS, MHA, MPH; Chief Editor: Iqbal Ahmed, MBBS, FRCPsych(UK)  more...
Updated: Oct 26, 2015

Practice Essentials

Delirium is defined as a transient, usually reversible, cause of cerebral dysfunction and manifests clinically with a wide range of neuropsychiatric abnormalities. It can occur at any age, but it occurs more commonly in patients who are elderly and have compromised mental status.

Signs and symptoms

The clinical hallmarks of delirium are decreased attention span and a waxing and waning type of confusion. Symptoms include the following:

  • Clouding of consciousness
  • Difficulty maintaining or shifting attention
  • Disorientation
  • Illusions
  • Hallucinations
  • Fluctuating levels of consciousness
  • Dysphasia
  • Dysarthria
  • Tremor
  • Asterixis in hepatic encephalopathy and uremia
  • Motor abnormalities

See Clinical Presentation for more detail.


The diagnosis of delirium is clinical. No laboratory test can diagnose delirium.

Diagnostic criteria

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for delirium is as follows[1] :

  • Disturbance in attention (ie, reduced ability to direct, focus, sustain, and shift attention) and awareness.
  • Change in cognition (eg, memory deficit, disorientation, language disturbance, perceptual disturbance) that is not better accounted for by a preexisting, established, or evolving dementia.
  • The disturbance develops over a short period (usually hours to days) and tends to fluctuate during the course of the day.
  • There is evidence from the history, physical examination, or laboratory findings that the disturbance is caused by a direct physiologic consequence of a general medical condition, an intoxicating substance, medication use, or more than one cause.

Assessment instruments

Some of the measures used to identify delirium include the following:

  • Confusion Assessment Method (CAM)
  • Delirium Symptom Interview (DSI)
  • Confusion Assessment Method for the Intensive Care Unit (CAM-ICU)
  • Intensive Care Delirium Screening Checklist (ICDSC)

Delirium symptom severity can be assessed by the Delirium Detection Scale (DDS) and the Memorial Delirium Assessment Scale (MDAS).

See Workup for more detail.


The goal of treatment is to determine the cause of the delirium and stop or reverse it. Components of delirium management include supportive therapy and pharmacologic management.

Fluid and nutrition should be given carefully because the patient may be unwilling or physically unable to maintain a balanced intake. For the patient suspected of having alcohol toxicity or alcohol withdrawal, therapy should include multivitamins, especially thiamine.

Reorientation techniques or memory cues such as a calendar, clocks, and family photos may be helpful. The environment should be stable, quiet, and well-lighted.

Delirium that causes injury to the patient or others should be treated with medications. The most common medications used are neuroleptics. Benzodiazepines often are used for withdrawal states.

See Treatment and Medication for more detail.



Delirium or acute confusional state is a transient global disorder of cognition. The condition is a medical emergency associated with increased morbidity and mortality rates. Early diagnosis and resolution of symptoms are correlated with the most favorable outcomes. Therefore, it must be treated as a medical emergency.

Delirium is not a disease but a syndrome with multiple causes that result in a similar constellation of symptoms. Delirium is defined as a transient, usually reversible, cause of cerebral dysfunction and manifests clinically with a wide range of neuropsychiatric abnormalities. The clinical hallmarks are decreased attention span and a waxing and waning type of confusion.

Delirium often is unrecognized or misdiagnosed and commonly is mistaken for dementia, depression, mania, an acute schizophrenic reaction, or part of old age (patients who are elderly are expected to become confused in the hospital).



Based on the state of arousal, 3 types of delirium are described. Hyperactive delirium is observed in patients in a state of alcohol withdrawal or intoxication with phencyclidine (PCP), amphetamine, and lysergic acid diethylamide (LSD). Hypoactive delirium is observed in patients in states of hepatic encephalopathy and hypercapnia. In mixed delirium, individuals display daytime sedation with nocturnal agitation and behavioral problems.

The mechanism of delirium still is not fully understood. Delirium results from a wide variety of structural or physiological insults. The neuropathogenesis of delirium has been studied in patients with hepatic encephalopathy and alcohol withdrawal. Research in these areas still is limited. The main hypothesis is reversible impairment of cerebral oxidative metabolism and multiple neurotransmitter abnormalities. The following observations support the hypothesis of multiple neurotransmitter abnormalities.


Data from animal and clinical studies support the hypothesis that acetylcholine is one of the critical neurotransmitters in the pathogenesis of delirium.[2] A small prospective study among patients who have undergone elective hip replacement surgery showed reduced preoperative plasma cholinesterase activity in as many as one quarter of patients. In addition, reduced preoperative cholinesterase levels were significantly correlated with postoperative delirium.[3]

Clinically, good reasons support this hypothesis. Anticholinergic medications are a well-known cause of acute confusional states, and patients with impaired cholinergic transmission, such those with Alzheimer disease, are particularly susceptible. In patients with postoperative delirium, serum anticholinergic activity is increased.


In the brain, a reciprocal relationship exists between cholinergic and dopaminergic activities. In delirium, an excess of dopaminergic activity occurs. Symptomatic relief occurs with antipsychotic medications such as haloperidol and other neuroleptic dopamine blockers.

Other neurotransmitters

Serotonin: Human and animal studies have found that serotonin is increased in patients with hepatic encephalopathy and septic delirium. Hallucinogens such as LSD act as agonists at the site of serotonin receptors. Serotoninergic agents also can cause delirium.

Gamma-aminobutyric acid (GABA): In patients with hepatic encephalopathy, increased inhibitory GABA levels also are observed. An increase in ammonia levels occurs in patients with hepatic encephalopathy, which causes an increase in the amino acids glutamate and glutamine, which are precursors to GABA. Decreases in CNS GABA levels are observed in patients with delirium resulting from benzodiazepine and alcohol withdrawal.

Cortisol and beta-endorphins: Delirium has been associated with the disruption of cortisol and beta-endorphin circadian rhythms. This mechanism has been suggested as a possible explanation for delirium caused by exogenous glucocorticoids.

Disturbed melatonin disturbance has been associated with sleep disturbances in delirium.[4]

Inflammatory mechanism

Recent studies have suggested a role for cytokines, such as interleukin-1 and interleukin-6, in the pathogenesis of delirium. Following a wide range of infectious, inflammatory, and toxic insults, endogenous pyrogen, such as interleukin-1, is released from the cells. Head trauma and ischemia, which frequently are associated with delirium, are characterized by brain responses that are mediated by interleukin-1 and interleukin-6.[5, 6]

Stress reaction mechanism

Studies indicate psychosocial stress and sleep deprivation facilitate the onset of delirium.

Structural mechanism

The specific neuronal pathways that cause delirium are unknown. Imaging studies of metabolic (eg, hepatic encephalopathy) and structural (eg, traumatic brain injury, stroke) factors support the hypothesis that certain anatomical pathways may play a more important role than others. The reticular formation and its connections are the main sites of arousal and attention. The dorsal tegmental pathway projecting from the mesencephalic reticular formation to the tectum and the thalamus is involved in delirium.

Disrupted blood-brain barrier can allow neurotoxic agents and inflammatory cytokines to enter the brain and may cause delirium. Contrast-enhanced MRI can be used to assess the blood-brain barrier.[7, 8]

Visuoperceptual deficits in delirium such as hallucinations and delusions are not due to the underlying cognitive impairment.[9] Visual hallucinations during alcohol-withdrawal delirium are seen in subjects with polymorphisms of genes coding for dopamine transporter and catechol-O-methyltransferase (COMT).[10]



In patients who are admitted with delirium, mortality rates are 10-26%.[11]

Patients who develop delirium during hospitalization have a mortality rate of 22-76% and a high rate of death during the months following discharge.[12]

In patients who are elderly and patients in the postoperative period, delirium may result in a prolonged hospital stay, increased complications, increased cost, and long-term disability.[13]

According to one study, delirium is common and associated with worse survival and greater resource consumption in those with cardiac critical illness. Among 590 patients included, the prevalence of cardiac (C)ICU delirium was 20.3%. Delirious patients were older, had greater disease severity, required longer ICU stays (5 vs 2 days; P < .001), and had higher mortality (27% vs 3%; P < .001).[14]




Delirium is common in the United States. It has been found in 14-56% of elderly patients who are hospitalized. Delirium is present in 10-22% of elderly patients at the time of admission, with an additional 10-30% of cases developing after admission. Delirium has been found in 40% of patients admitted to intensive care units. Prevalence of postoperative delirium following general surgery is 5-10% and as high as 42% following orthopedic surgery. As many as 80% of patients develop delirium near death. Delirium is extremely common among nursing home residents.


Delirium can occur at any age, but it occurs more commonly in patients who are elderly and have compromised mental status. Delirium can occur on top of an underlying dementia. This diagnosis here requires not only a careful mental status but also a thorough history from the patient's family and the staff as well as a comprehensive chart review.

Contributor Information and Disclosures

Kannayiram Alagiakrishnan, MD, MBBS, MHA, MPH Associate Professor, Department of Medicine, Division of Geriatric Medicine, University of Alberta Faculty of Medicine and Dentistry, Canada

Kannayiram Alagiakrishnan, MD, MBBS, MHA, MPH is a member of the following medical societies: American College of Physicians, American Geriatrics Society

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Chief Editor

Iqbal Ahmed, MBBS, FRCPsych(UK) Faculty, Department of Psychiatry, Tripler Army Medical Center; Clinical Professor of Psychiatry, Uniformed Services University of the Health Sciences; Clinical Professor of Psychiatry, Clinical Professor of Geriatric Medicine, University of Hawaii, John A Burns School of Medicine

Iqbal Ahmed, MBBS, FRCPsych(UK) is a member of the following medical societies: Academy of Psychosomatic Medicine, American Neuropsychiatric Association, American Society of Clinical Psychopharmacology, Royal College of Psychiatrists, American Association for Geriatric Psychiatry, American Psychiatric Association

Disclosure: Nothing to disclose.

Additional Contributors

Mohammed A Memon, MD Chairman and Attending Geriatric Psychiatrist, Department of Psychiatry, Spartanburg Regional Medical Center

Mohammed A Memon, MD is a member of the following medical societies: American Association for Geriatric Psychiatry, American Medical Association, American Psychiatric Association

Disclosure: Nothing to disclose.


Patricia Blanchette, MD Department Chair and Director, Geriatric Medicine Fellowship Program, Professor of Geriatric Medicine, John A Burns School of Medicine, University of Hawaii

Patricia Blanchette, MD is a member of the following medical societies: American College of Physicians, American Geriatrics Society, American Medical Association, American Medical Directors Association, Gerontological Society of America, and Hawaii Medical Association

Disclosure: Nothing to disclose.

  1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. 5th ed. Washington, DC: American Psychiatric Association; 2013.

  2. White S. The neuropathogenesis of delirium. Rev Clin Gerontol. 2002. 12:62-67.

  3. Cerejeira J, Batista P, Nogueira V, et al. Low preoperative plasma cholinesterase activity as a risk marker of postoperative delirium in elderly patients. Age Ageing. 2011 Sep. 40(5):621-6. [Medline].

  4. Shigeta H, Yasui A, Nimura Y, et al. Postoperative delirium and melatonin levels in elderly patients. Am J Surg. 2001 Nov. 182(5):449-54. [Medline].

  5. de Rooij SE, van Munster BC, Korevaar JC, Levi M. Cytokines and acute phase response in delirium. J Psychosom Res. 2007 May. 62(5):521-5. [Medline].

  6. Rudolph JL, Ramlawi B, Kuchel GA, et al. Chemokines are associated with delirium after cardiac surgery. J Gerontol A Biol Sci Med Sci. 2008 Feb. 63(2):184-9. [Medline]. [Full Text].

  7. Ebersoldt M, Sharshar T, Annane D. Sepsis-associated delirium. Intensive Care Med. 2007 Jun. 33(6):941-50. [Medline].

  8. Banks WH. The aged blood- brain barrier: A substrate for CNS disease. Facts, Research and Intervention in Geriatrics. 2000. 2000(2):521-530.

  9. Brown LJ, McGrory S, McLaren L, Starr JM, Deary IJ, Maclullich AM. Cognitive visual perceptual deficits in patients with delirium. J Neurol Neurosurg Psychiatry. 2009 Jun. 80(6):594-9. [Medline].

  10. Limosin F, Loze JY, Boni C, et al. The A9 allele of the dopamine transporter gene increases the risk of visual hallucinations during alcohol withdrawal in alcohol-dependent women. Neurosci Lett. 2004 May 20. 362(2):91-4. [Medline].

  11. McCusker J, Cole M, Abrahamowicz M, Primeau F, Belzile E. Delirium predicts 12-month mortality. Arch Intern Med. 2002 Feb 25. 162(4):457-63. [Medline].

  12. American Psychiatric Association. Practice guideline for the treatment of patients with delirium. Am J Psychiatry. 1999 May. 156(5 Suppl):1-20. [Medline].

  13. Marcantonio ER, Kiely DK, Simon SE, et al. Outcomes of older people admitted to postacute facilities with delirium. J Am Geriatr Soc. 2005 Jun. 53(6):963-9. [Medline].

  14. Pauley E, Lishmanov A, Schumann S, Gala GJ, van Diepen S, Katz JN. Delirium is a robust predictor of morbidity and mortality among critically ill patients treated in the cardiac intensive care unit. Am Heart J. 2015 Jul. 170 (1):79-86, 86.e1. [Medline].

  15. Folstein MF, Folstein SE, McGugh PR. "Mini- Mental State".A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res. Nov. 1975. 12(3):189-98.

  16. Yesavage JA, Brink TL, Rose TL, et al. Development and validation of a geriatric depression screening scale: a preliminary report. J Psychiatr Res. Apr 1983. 17:37-49.

  17. McAvay GJ, Van Ness PH, Bogardus ST Jr, Zhang Y, Leslie DL, Leo-Summers LS. Depressive symptoms and the risk of incident delirium in older hospitalized adults. J Am Geriatr Soc. 2007 May. 55(5):684-91. [Medline].

  18. Farrell KR, Ganzini L. Misdiagnosing delirium as depression in medically ill elderly patients. Arch Intern Med. 1995 Dec 11-25. 155(22):2459-64. [Medline].

  19. Cole M, McCusker J, Dendukuri N, Han L. The prognostic significance of subsyndromal delirium in elderly medical inpatients. J Am Geriatr Soc. 2003 Jun. 51(6):754-60. [Medline].

  20. Ouimet S, Riker R, Bergeron N, Cossette M, Kavanagh B, Skrobik Y. Subsyndromal delirium in the ICU: evidence for a disease spectrum. Intensive Care Med. 2007 Jun. 33(6):1007-13. [Medline].

  21. Inouye SK, van Dyck CH, Alessi CA. Clarifying confusion: the confusion assessment method. A new method for detection of delirium. Ann Intern Med. 1990 Dec 15. 113(12):941-8. [Medline].

  22. Alagiakrishnan K, Marrie T, Rolfson D et al. Gaps in patient care practices to prevent hospital-acquired delirium. Can Fam Physician. 2009. 55:e41-6. [Medline].

  23. Neto AS, Nassar AP Jr, Cardoso SO, Manetta JA, Pereira VG, Espósito DC, et al. Delirium screening in critically ill patients: A systematic review and meta-analysis. Crit Care Med. 2012 Jun. 40(6):1946-51. [Medline].

  24. Inouye SK, Kosar CM, Tommet D, et al. The CAM-S: development and validation of a new scoring system for delirium severity in 2 cohorts. Ann Intern Med. 2014 Apr 15. 160(8):526-33. [Medline].

  25. Brooks M. New scoring tool gauges severity of delirium. Medscape Medical News. April 15, 2014. [Full Text].

  26. Rudolph JL, Jones RN, Rasmussen LS, Silverstein JH, Inouye SK, Marcantonio ER. Independent vascular and cognitive risk factors for postoperative delirium. Am J Med. 2007 Sep. 120(9):807-13. [Medline].

  27. Perry SW. Organic mental disorders caused by HIV: update on early diagnosis and treatment. Am J Psychiatry. 1990 Jun. 147(6):696-710. [Medline].

  28. Van Muster BC, Korevaar JC, Korse CM , Bonfer JM, Zwinderman AH, DeRooji SE. Serum S 100B in elderly patients with and without delirium. International Journal of Geriatric Psychiatry. 2010. 25(3):234-239.

  29. Van Rompaey B, Elseviers M M, Van Drom W, Fromont V, Jorens P G. The effect of earplugs during the night on the onset of delirium and sleep perception: a randomized controlled trial in intensive care patients. Critical Care. 2012. 16:

  30. Overshott R, Karim S, Burns A. Cholinesterase inhibitors for delirium. Cochrane Database Syst Rev. 2008 Jan 23. CD005317. [Medline].

  31. van Eijk MM, Roes KC, Honing ML, Kuiper MA, Karakus A, van der Jagt M. Effect of rivastigmine as an adjunct to usual care with haloperidol on duration of delirium and mortality in critically ill patients: a multicentre, double-blind, placebo-controlled randomised trial. Lancet. 2010 Nov 27. 376(9755):1829-37. [Medline].

  32. Kishi T, Hirota T, Matsunaga S, Iwata N. Antipsychotic medications for the treatment of delirium: a systematic review and meta-analysis of randomised controlled trials. J Neurol Neurosurg Psychiatry. 2015 Sep 4. [Medline].

  33. Anderson CP, Ngo LH, Marcantonio ER. Complications in Postacute Care Are Associated with Persistent Delirium. J Am Geriatr Soc. 2012 May 30. [Medline].

  34. Maclullich AMJ, Beaglehole A, Hall RA, Meagher DJ. Delirium and long-term cognitive impairment. International Review of Psychiatry. 2009. 21(1):30-42.

  35. Alagiakrishnan K, Marrie T, Rolfson D, Coke W, Camicioli R, Duggan D. Simple cognitive testing (Mini-Cog) predicts in-hospital delirium in the elderly. J Am Geriatr Soc. 2007 Feb. 55(2):314-6. [Medline].

  36. Alagiakrishnan K, Wiens CA. An approach to drug induced delirium in the elderly. Postgrad Med J. 2004 Jul. 80(945):388-93. [Medline].

  37. Alsop DC, Fearing MA, Johnson K, Sperling R, Fong TG, Inouye SK. The role of neuroimaging in elucidating delirium pathophysiology. J Gerontol A Biol Sci Med Sci. 2006 Dec. 61(12):1287-93. [Medline].

  38. Bergeron N, Dubois MJ, Dumont M, Dial S, Skrobik Y. Intensive Care Delirium Screening Checklist: evaluation of a new screening tool. Intensive Care Med. 2001. 27:859-864.

  39. Chan D, Brennan NJ. Delirium: making the diagnosis, improving the prognosis. Geriatrics. 1999 Mar. 54(3):28-30, 36, 39-42. [Medline].

  40. Day JJ, Bayer AJ, McMahon M. Thiamine status, vitamin supplements and postoperative confusion. Age Ageing. 1988 Jan. 17(1):29-34. [Medline].

  41. Ely EW, Inouye SK, Bernard GR. Delirium in mechanically ventilated patients: validity and reliability of the confusion assessment method for the intensive care unit (CAM-ICU). JAMA. 2001 Dec 5. 286(21):2703-10. [Medline].

  42. Henderson D. Delirium: Common Treatment No Better Than Placebo. Medscape Medical News. Available at Accessed: September 5, 2013.

  43. Hung OL, Lewin NA, Howland MA. Herbal preparations. Goldfrank LR, Flomenbaum NE, Lewin NA, et al, eds. Goldfrank's Toxicologic Emergencies. 7th ed. New York: McGraw-Hill; 2002. 1129.

  44. Inouye SK. The dilemma of delirium: clinical and research controversies regarding diagnosis and evaluation of delirium in hospitalized elderly medical patients. Am J Med. 1994 Sep. 97(3):278-88. [Medline].

  45. Inouye SK, Bogardus ST, Charpentier PA, et al. A multicomponent intervention to prevent delirium in hospitalized older patients. N Engl J Med. 1999 Mar 4. 340(9):669-76. [Medline].

  46. Inouye SK, Charpentier PA. Precipitating factors for delirium in hospitalized elderly persons. Predictive model and interrelationship with baseline vulnerability. JAMA. 1996 Mar 20. 275(11):852-7. [Medline].

  47. Jones RN, Yang FM, Zhang Y, Kiely DK, Marcantonio ER, Inouye SK. Does educational attainment contribute to risk for delirium? A potential role for cognitive reserve. J Gerontol A Biol Sci Med Sci. 2006 Dec. 61(12):1307-11. [Medline].

  48. Leslie DL, Zhang Y, Holford TR, Bogardus ST, Leo- Summers LS, Inouye SK. Premature death associated with delirium at 1-year follow-up. Arch Intern Med. 2005 July. 165(14):1657-62. [Medline].

  49. Lipowski ZJ. Delirium (acute confusional states). JAMA. 1987 Oct 2. 258(13):1789-92. [Medline].

  50. Lipowski ZJ. Delirium in the elderly patient. N Engl J Med. 1989 Mar 2. 320(9):578-82. [Medline].

  51. Liptzin B, Levkoff SE. An empirical study of delirium subtypes. Br J Psychiatry. 1992 Dec. 161:843-5. [Medline].

  52. Liptzin B, Levkoff SE, Gottlieb GL. Delirium. J Neuropsychiatry Clin Neurosci. 1993 Spring. 5(2):154-60. [Medline].

  53. McAvay GJ, Van Ness PH, Bogardus ST Jr, Zhang Y, Leslie DL, Leo-Summers LS. Depressive symptoms and the risk of incident delirium in older hospitalized adults. J Am Geriatr Soc. 2007 May. 55(5):684-91. [Medline].

  54. O'Keeffe ST, Ni Chonchubhair A. Postoperative delirium in the elderly. Br J Anaesth. 1994 Nov. 73(5):673-87. [Medline].

  55. O'Keeffee ST. Delirium in the elderly. Age Ageing. 1999 Sep. 28 Suppl 2:5-8. [Medline].

  56. Obrecht R, Okhomina FO, Scott DF. Value of EEG in acute confusional states. J Neurol Neurosurg Psychiatry. 1979 Jan. 42(1):75-7. [Medline].

  57. Otter H, Martin J, Bäsell K, von Heymann C, Hein OV, Böllert P. Validity and reliability of the DDS for severity of delirium in the ICU. Neurocrit Care. 2005. 2(2):150-8. [Medline].

  58. Ouimet S, Riker R, Bergeon N, Cosette M, Kavanagh B, Skrobik Y. Subsyndromal delirium in the ICU: evidence for a disease spectrum. Intensive Care Med. 2007 Apr 3. 33(6):1007-1013. [Medline].

  59. Page VJ, Ely EW, Gates S, et al. Effect of intravenous haloperidol on the duration of delirium and coma in critically ill patients (Hope-ICU): a randomised, double-blind, placebo-controlled trial. Lancet Respir Med. 2013 Aug 21.

  60. Sipahimalani A, Masand PS. Use of risperidone in delirium: case reports. Ann Clin Psychiatry. 1997 Jun. 9(2):105-7. [Medline].

  61. Teslyar P, Stock VM, Wilk CM, Camsari U, Ehrenreich MJ, Himelhoch S. Prophylaxis with Antipsychotic Medication Reduces the Risk of Post-Operative Delirium in Elderly Patients: A Meta-Analysis. Psychosomatics. 2013 Feb 1. [Medline].

  62. Trzepacz PT. Delirium. Advances in diagnosis, pathophysiology, and treatment. Psychiatr Clin North Am. 1996 Sep. 19(3):429-48. [Medline].

  63. Matthews FE, Arthur A, Barnes LE, Bond J, Jagger C, Robinson L, et al. A two-decade comparison of prevalence of dementia in individuals aged 65 years and older from three geographical areas of England: results of the Cognitive Function and Ageing Study I and II. Lancet. 2013 Oct 26. 382 (9902):1405-12. [Medline].

Table 1. Differentiating Features of Delirium and Dementia
Features Delirium Dementia
Onset Acute Insidious
Course Fluctuating Progressive
Duration Days to weeks Months to years
Consciousness Altered Clear
Attention Impaired Normal, except in severe dementia
Psychomotor changes Increased or decreased Often normal
Reversibility Usually Rarely
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