Table Four

Comparison of Delirium, Dementia & Depression

Onset Sudden, abrupt, hours to days, worse at twilight Insidious, slow, often unrecognized Sudden or insidious, corresponds with life changes
Course over 24 hours Fluctuating, usually with nighttime exacerbations Fairly stable, stress may produce more rapid change Fairly stable, may be worse in the morning
Consciousness Reduced or fluctuating Clear Clear
Alertness Increased, decreased, or variable Generally normal Normal
Psychomotor activity Increased (autonomic hyperarousal), decreased, mixed; variable Variable Variable, agitation or retardation
Duration of present illness Hours to weeks (rarely over a month) Months to years Variable (at least 2 weeks per DSM-IV), may be months to years
Attention Globally impaired, fluctuates Generally normal Little impairment, distractible
Orientation Usually impaired, variable, fluctuates Often impaired (may answer close to right) Usually normal, may answer "don't know"
Memory Impaired recent & immediate Impaired recent & remote Patcy, "islands" of intact memory
Thinking Disorganized, distorted, fragmented, slowed or accelerated Difficulty with abstraction; agnosia, impoverished thought, impaired judgment, word-finding difficulty Intact. Themes of hopelessness, helplessness, guilt
Perception Distorted, illusions, delusions, hallucinations; difficulty distinguishing perceptions of reality Normally intact, but may have hallucinations Intact, delusions and hallucinations in severe cases
Speech Often incoherent, slow or rapid Difficulty word finding, perseveration May be slow
Affect Variable Superficial, labile at times Flat, exaggerated complaints
Sleep-wake cycle Disturbed, may be reversed Can be fragmented Disturbed, often early morning awakenings
Insight May be present when lucid Often absent May or may not be present


Adapted from: Foreman & Zane, 1996; Henry 2002; Lipowski 1992

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