The first cause you would think of if there is a change in mental status in an older adult, particularly confusion, is:

A primary cause of change in mental status, particularly confusion, in older adults is drug toxicity.

Drug toxicity occurs when a person has accumulated too much of a drug in their bloodstream which results into  adverse effects on the body.

dude the first thing it says is that copied answers will get a zero. plus it would take anyone on an incredibly long time to answer. ive seen 2 people asking the exact same question and their questions got taken down. i have the assignment too, and im in the progress of doing it. i suggest going to a more private website, because this is the first place teachers look.