An 88-year-old man is evaluated at an assisted-living facility. Staff members have noticed that the patient seems more withdrawn than usual, is less interactive with other residents, and no longer attends social functions. At times, he seems confused and answers questions nonsensically or has difficulty navigating simple conversations. At other times, he seems normal and cheerful. The staff has not observed any crying spells. He appropriately manages his own medications and finances. There have been no recent changes in his medications. He has had no recent falls, illness, or fever.

On physical examination, vital signs are normal. The patient is appropriately conversant. The general medical examination is unremarkable. On neurologic examination, Mini-Mental State Examination score is 25/30, which is unchanged over the past 18 months. A two-question depression screen is negative. The remainder of the neurologic examination is unremarkable.

Which of the following is the most appropriate management of this patient?