Dementia, Delirium and Depression
|
Feature |
Delirium |
Dementia |
Depression |
| Onset | Hours to days | Months to years | Weeks to months |
| Pattern | Fluctuant throughout the day |
Progressive over time Often worse at night |
Episodic Often worse in the morning |
| Areas of impairment | Global | At least two areas affected | Specific impairments within several areas of function |
| Alertness | Often impaired | Often normal | Often normal |
| Affect | Often agitated but can be hypoactive | Dependent on subtype or severity | Flattened |
| Course | Reversible | Irreversible over time | Reversible |
As already discussed, there can be considerable overlap between dementia, delirium and depression.
Delirium is an acute, reversible organic mental syndrome characterised by reduced ability to maintain attention to external stimuli and disorganised thinking.
Depression is a mental state of depressed mood characterised by feelings of sadness, despair and discouragement.
This table describes the classical differentiating features of each.