We have a small contained life, no outside events together or large outside gatherings. He can tolerate one or two people coming over, and I tell him he's free to go into the bedroom to rest whenever he likes.
Right now he's on an anti-depressant, Citalopram. Before that, it was donepezil (Aricept) for a couple of years, but I didn't notice any benefit.
What I understand about dementia is that sensory stimulation should be kept to a minimum. The brain is already challenged enough.