Reduced ability to maintain attention to external stimuli and to appropriately shift attention to new external stimuli. Thus at least 1 of:
1- Questions had to be repeated because attention wandered
2- Perseverated answers to previous questions

Disorganized thinking

Confusion developed over a short period of time

Fluctuating level of confusion

At least 2 out of 6 of:
1- Reduced level of consciousness
2- Perceptual disturbances
3- Disturbance of sleep-wake cycle
4- Increased or decreased psychomotor activity
5- Disorientation to time, place, or person
6- Memory impairment

Either of the following:
1- Evidence that an organic factor initiated and maintained this confusion
2- Confusion cannot be accounted for by any nonorganic mental disorder