Written by Being Patient

Personality changes are not often talked about as a common symptom of dementia, so when these changes start to appear in a friend, care subject or loved one, they can seem abrupt, surprising, and disarming. While new differences in behavior — from sudden anger, irritation, anxiety, to, even, usual sexual behavior that seems completely out of character — can be especially difficult for caregivers to navigate, understanding the science behind them can make things a little easier.

First, it’s helpful to understand the way neurodegenerative diseases change the brain. Alzheimer’s begins in the hippocampus, a brain region responsible for learning and memory. The hippocampus is also key for regulating a person’s emotional responses. This region is particularly vulnerable to neuropsychiatric conditions, and people living with Alzheimer’s will experience massive cell loss in the hippocampus, which can lead to behavioral and personality changes like stress, anxiety, and depression, to name a few.

Don Kent, a former trial lawyer, was misdiagnosed six times before discovering he had Lewy Body Dementia. “All of a sudden, I became this sort of explosive personality, very angry, saying mean things to people which I had never done before,” Kent told Being Patient. “And about the same time I also felt a loss of my sense of taste, and I say loss because to me it was a loss, but overtime I’ve learned that it’s a hallucination, a taste hallucination.” Kent has also experienced visual hallucinations since his diagnosis.

According to Dr. Bruce Miller, a behavioral neurologist at the University of California, San Francisco, certain behavioral symptoms may appear much earlier than an official diagnosis: “It is very common to see a patient with early Alzheimer’s disease, sometimes even before they’ve manifested a memory disorder, to be anxious, hyper-reactive and very concerned about things that are going on around them,” Miller said.

As neurodegeneration progresses through the brain, more complex behavioral symptoms like severe agitation or hallucinations become common in later stages. Loss of communication abilities and challenging behavioral symptoms often go hand in hand, which can in turn cause even more personality changes, as people become frustrated struggling to express discomfort, pain, or unmet wants or needs.

Miller offered advice to caregivers that are just beginning to notice behavioral changes in their loved one. 

“Figure out what the triggers are,” Miller said. “Figure out whether maybe one of the new medicines is actually making paranoia worse rather than better. My rule of thumb is: When there’s a sudden behavior change, take a broad look at your loved one. Make sure they don’t have an infection. Make sure that nothing’s changed in the brain.”

Experts suggest that learning how to recognize the signs of pain in people living with dementia could help explain and mitigate some new behavioral changes. And that keeping a journal to track behavioral and personality changes over time could help to illuminate trends around certain triggers and serve as a guide when speaking to the person’s doctor or other care providers.

Other experts — including caregiving consultant Teepa Snow — recommend finding a routine that works for your loved one, to help provide comfort in familiarity and ease anxiety throughout the day. Engaging in active movement with your loved one, like going for a walk or participating in outdoor activities or hobbies, can reduce restlessness and boost mood.