Editing Delirium (section)

==Signs and symptoms==
Delirium exists across a range of [[arousal]] levels, either as a state between normal wakefulness/alertness and coma (hypoactive) or as a state of heightened psychophysiological arousal (hyperactive). It can also alternate between the two (mixed level of activity). While requiring an acute disturbance in attention, awareness, and [[cognition]], the syndrome of delirium encompasses a broad range of additional neuropsychiatric disturbances.<ref name="American_Psychiatric_Publishing_2008" />

* '''Inattention''': A disturbance in [[attention]] is required for delirium diagnosis. This may present as an impaired ability to direct, focus, sustain, or shift [[attention]].<ref name="DSM-5-TR" />
* '''Memory impairment''': The [[memory impairment]] that occurs in delirium is often due to an inability to [[encoding (memory)|encode]] new information, largely as a result of having impaired [[attention]]. Older memories already in [[storage (memory)|storage]] are retained without need of concentration, so previously formed long-term memories (i.e., those formed before the onset of delirium) are usually preserved in all but the most severe cases of delirium, though [[recall (memory)|recall]] of such information may be impaired due to global impairment in cognition.
* '''Disorientation:''' A person may be disoriented to self, place, or time. Additionally, a person may be 'disoriented to situation' and not recognize their environment or appreciate what is going on around them.
* '''Disorganized thinking''': [[Thought disorder|Disorganized thinking]] is usually noticed with speech that makes limited sense with apparent irrelevancies, and can involve [[Alogia|poverty of speech]], [[Derailment (thought disorder)|loose associations]], [[perseveration]], [[Tangential speech|tangentiality]], and other signs of a formal thought disorder.
* '''Language disturbances''': [[Anomic aphasia]], [[paraphasia]], impaired comprehension, [[agraphia]], and word-finding difficulties all involve impairment of linguistic information processing.
* '''Sleep/wake disturbances''': Sleep disturbances in delirium reflect disruption in both sleep/wake and circadian rhythm regulation, typically characterized by fragmented sleep or even sleep-wake cycle reversal (i.e., active at night, sleeping during the day), including as an early sign preceding the onset of delirium.
* '''Psychotic and other erroneous beliefs''': Symptoms of [[psychosis]] include suspiciousness, overvalued ideation and frank delusions. [[Delusions]] are typically poorly formed and less [[Stereotypy|stereotyped]] than in schizophrenia or Alzheimer's disease. They usually relate to persecutory themes of impending danger or threat in the immediate environment (e.g., being poisoned by nurses).
* '''Perceptual disturbances''': These can include [[illusion]]s, which involve the misperception of real stimuli in the environment, or [[hallucination]]s, which involve the perception of stimuli that do not exist.
* '''Mood lability''': Distortions to perceived or communicated emotional states as well as [[Emotional lability|fluctuating emotional states]] can manifest in delirium (e.g., rapid changes between terror, sadness, joking, fear, anger, and frustration).<ref>{{cite journal | vauthors = Leentjens AF, Rundell J, Rummans T, Shim JJ, Oldham R, Peterson L, Philbrick K, Soellner W, Wolcott D, Freudenreich O | title = Delirium: An evidence-based medicine (EBM) monograph for psychosomatic medicine practice, commissioned by the Academy of Psychosomatic Medicine (APM) and the European Association of Consultation Liaison Psychiatry and Psychosomatics (EACLPP) | journal = Journal of Psychosomatic Research | volume = 73 | issue = 2 | pages = 149–152 | date = August 2012 | pmid = 22789420 | doi = 10.1016/j.jpsychores.2012.05.009 }}</ref>
* '''Motor activity changes:''' Delirium has been commonly classified into psychomotor subtypes of hypoactive, hyperactive, and mixed level of activity,<ref>{{cite journal | vauthors = Lipowski ZJ | title = Delirium in the elderly patient | journal = The New England Journal of Medicine | volume = 320 | issue = 9 | pages = 578–582 | date = March 1989 | pmid = 2644535 | doi = 10.1056/NEJM198903023200907 }}</ref> though studies are inconsistent as to their prevalence.<ref>{{cite journal | vauthors = de Rooij SE, Schuurmans MJ, van der Mast RC, Levi M | title = Clinical subtypes of delirium and their relevance for daily clinical practice: a systematic review | journal = International Journal of Geriatric Psychiatry | volume = 20 | issue = 7 | pages = 609–615 | date = July 2005 | pmid = 16021665 | doi = 10.1002/gps.1343 | s2cid = 37993802 }}</ref> Hypoactive cases are prone to non-detection or misdiagnosis as depression. A range of studies suggests that motor subtypes differ regarding underlying pathophysiology, treatment needs, functional prognosis, and risk of mortality, though inconsistent subtype definitions and poorer detection of hypoactive subtypes may influence the interpretation of these findings.<ref>{{cite journal | vauthors = Meagher D | title = Motor subtypes of delirium: past, present and future | journal = International Review of Psychiatry | volume = 21 | issue = 1 | pages = 59–73 | date = February 2009 | pmid = 19219713 | doi = 10.1080/09540260802675460 | s2cid = 11705848 }}</ref> The notion of unifying hypoactive and hyperactive states under the construct of delirium is commonly attributed to Lipowski.<ref name="Lipowski">{{Cite book|title=Delirium: Acute Brian Failure in Man|publisher=Charles C Thomas |isbn=0-398-03909-7 |location=Springfield, IL |year=1980}}</ref>
** '''Hyperactive''' symptoms include hyper-vigilance, restlessness, fast or loud speech, irritability, combativeness, impatience, swearing, singing, laughing, uncooperativeness, euphoria, anger, wandering, easy startling, fast motor responses, distractibility, tangentiality, nightmares, and persistent thoughts (hyperactive sub-typing is defined with at least three of the above).<ref name="Liptzin_1992">{{cite journal | vauthors = Liptzin B, Levkoff SE | title = An empirical study of delirium subtypes | journal = The British Journal of Psychiatry | volume = 161 | issue = 6 | pages = 843–845 | date = December 1992 | pmid = 1483173 | doi = 10.1192/bjp.161.6.843 | s2cid = 8754215 }}</ref>
** '''Hypoactive''' symptoms include decreased alertness, sparse or slow speech, lethargy, slowed movements, staring, and apathy.<ref name="Liptzin_1992" />
** '''Mixed level of activity''' describes instances of delirium where activity level is either normal or fluctuating between hyperactive and hypoactive.<ref name=DSM-5-TR />