Delirium, dementia, depression

Delirium: onset in hours to days, fluctuating, attention and consciousness altered, reversible. Always look for a cause. Dementia: onset over months to years, progressive, consciousness intact until very late, memory affected first. Depression: onset over weeks, answers "I don't know", complains a lot about memory while performing well, mood low. New confusion in an older adult is delirium until proven otherwise. The three can coexist.

Clinical content reviewed by Ducamelle Louis, Registered Nurse