Table Four
Comparison of Delirium, Dementia & Depression
Feature |
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