TABLE 8-3 - Delirium versus Dementia

	Delirium	Dementia
Onset	Hours to days	Weeks to years
Course/duration	Fluctuates within a day. May last hours to weeks *	Stable within a day. May be permanent, reversible, or progressive over weeks to years
Attention	Impaired	May be impaired
Cognition	Impaired memory, orientation, language	Impaired memory, orientation, language, executive function
Perception	Hallucinations, delusions, misinterpretations	Hallucinations, delusions
Sleep/wake	Disturbed, may have complete day/night reversal	Disturbed, may have no pattern
Mood/emotion	Labile affect	Labile affect; mood disturbances
Identified precipitant	Likely precipitant is present	Identifiable precipitant not required

* DSM-IV does not specify a limit for the duration for delirum; clinical experience suggests resolution within days to weeks, in most cases.