Quick Clips From Faculty Experts: Examples of Hallucinations and Delusions

DR. DEVANAND: Alzheimer’s disease: Maybe 1 in 4 or 5 patients do develop delusions of the type we talked about, like stealing—“Somebody is stealing my things” and “My house is not my home.” And infidelity is quite important when it comes to a spouse, because that can be almost impossible to manage, because it becomes a very persistent and disruptive delusion.

Hallucinations as an initial symptom are really quite uncommon in Alzheimer’s disease. They do occur in Lewy body dementia. So if the first symptom a person presents is a hallucination, I start investigating to try to figure out what’s going on.

As the disease progresses, the psychosis can persist. But sometimes it just comes and goes. So there could be a period of a few months where they’re quite paranoid and delusional, and then, for a period of time, that seems to go away; but it can come back. And we really don’t have a good understanding of why it fluctuates over time like that. And so, being aware of it, monitoring it—especially for family members—can be quite difficult because of these variations over time.


Columbia University Medical Center
New York, NY

Faculty Insights

It is essential that medical providers be aware of how often people with dementia develop neuropsychiatric symptoms during the course of their illness.

—Pierre N. Tariot, MD