Illusions, Delusions, and Paranoia in Alzheimer's: What's the Connection?

Understanding symptoms of Alzheimer's disease and related dementia is hard because symptoms vary so much between people and as they change over the course of the disease—and even from day-to-day! This is, of course, difficult for caregivers as well as for the person living with the symptoms.

A family member and I had a conversation the other day, and she asked about a specific symptom: paranoia. Of course, like many people who have an older relative with Alzheimer's disease, we second-guess what could be a manifestation of the disease regularly!

Understanding delusions with Alzheimer’s

To be more accurate, delusions are the specific Alzheimer's disease symptom that leads to paranoia. The Alzheimer's Association explains delusions as "firmly held beliefs in things that are not real."¹

Delusions can result from Alzheimer's symptoms of confusion and memory loss. Still, they can also be caused by other medical conditions, such as an infection, so it is important to rule out medical causes.²

Common delusions are that family members or friends may be stealing things (because they cannot remember where they have put the item or may not "see it" even though it is there—more on illusions with Alzheimer's in a moment), that they are being followed, that someone is in their home, or that a loved one is an "impostor."²

It's also noted that delusions cannot be reasoned with, making it even more challenging to help the person experiencing them cope.³

Understanding illusions with Alzheimer’s

Illusions are misinterpretations of visual stimuli that the brain fails to recognize as what they are. These are unlike hallucinations, in which a person sees or hears people or things that are not present.^1,4

Behavior changes may occur as a result of the suspicious delusions the person is experiencing: hiding things, accusations and suspiciousness, agitation (that may lead to aggression), and being resistant to all or some people providing care or entering their space.²

Causes of Alzheimer's-related delusions

Like other symptoms of Alzheimer's, delusions are caused by the degeneration of the brain's cells and tissues. Accusations are not easy to deal with, especially if you are the one accused. Still, it is important to remember it is a symptom, even if it feels like a personal attack, though this does not always make it easier to deal with. Take the example of "missing" items; we know that the item is not really missing. It's instead misplaced, hidden, or simply the person cannot "see" where it is—even if it is there—and Alzheimer's disease directly causes those things.²

How to manage delusions and illusions with Alzheimer's

Most often, calmly acknowledging the problem as true and then distracting, generally by shifting the conversation away from rumination, is something we find helpful. Other suggestions might include identifying the causes or triggers of the situation or response, offering to help "look for" items that are "missing," and doing what you can to prevent the problem from arising.⁴

This includes helping to maintain routines, knowing where items may be hidden by the person and forgotten, having duplicate items (if "missing" items are consistent and not random—we have experienced the latter!), and ensuring adequate lighting to reduce eye-brain shadow-related trickery⁴.

Cross off other possible causes

It's important to ensure that a physical problem with vision or hearing, or other psychiatric disorders, is not causing the problem, too. Finally, the Alzheimer's Society of Cornwall and District in Ontario notes that in some cases, you may truly need to investigate a person's suspicions because, of course, they may be true and not a manifestation of Alzheimer's disease!⁴

Have you dealt with paranoia, illusions, and delusions associated with Alzheimer's? What strategies have helped you cope?