A 74-Year-Old Man Comes to the Office Due to Memory

A 74-year-old man comes to the office due to memory problems over the past several months.  He is accompanied by his wife.  The patient says, "I am worried about my memory.  I feel like I am losing my mind.  I can't remember what I've read in the newspaper, and I even have difficulty following the plot on TV shows."  His wife says, "He frequently misplaces things like his keys and wallet and can't recall names of individuals he should know.  She adds, "He used to like to cook and watch TV, but he doesn't seem to enjoy these things anymore.  When he attempted to make a favorite dish recently, he left out half the ingredients and burned the meal."  Over the past 2 months, the patient has been involved in 2 minor car accidents in which he was "not paying attention."  He recently told his wife that they are "ruined and going bankrupt," despite her multiple assurances that this is not so.  She says, "I show him the bank statements, but a few days later, it's as if he doesn't remember and he asks to see them again."  They went through a difficult time over the past year due to his suspicions that she had an affair, which were recently confirmed.  The patient's medical history is significant for gastroesophageal reflux disease, rheumatoid arthritis, and hypertension.  He has increased soreness and pain in his joints and neck that he attributes to "my body breaking down."  The patient has a history of thyroid cancer that was successfully treated 15 years earlier.  His medications include lisinopril, levothyroxine, hydrochlorothiazide, aspirin, and antacids.  Physical examination is unremarkable.  Laboratory studies, including vitamin B₁₂ and thyroid function, are normal. The patient is diagnosed with major depressive disorder, and antidepressant medication is started.  Three months later, his condition has significantly improved.  Examination of memory and concentration demonstrates clear improvement.  The patient's wife says that he is "back to his normal self and sharp as a whistle."  He has been driving without accidents.  They have started socializing again and have attended couples counseling to address issues with infidelity.  At a recent clinic visit, the patient and his wife ask about his prognosis, as they are planning their advance directive documents.  Which of the following disorders is the patient at increased risk of developing?

A) Delusional disorder
B) Generalized anxiety disorder
C) Late-onset bipolar disorder
D) Major frontotemporal neurocognitive disorder (Pick disease)
E) Major neurocognitive disorder due to Alzheimer disease (Alzheimer dementia)