More Than a "Memory Eraser": Understanding the Behavioral and Psychological Symptoms of Alzheimer's Disease

When people hear the words "Alzheimer's disease," the first image that comes to mind is usually "forgetting": forgetting what was just said, forgetting to turn off the stove, forgetting the way home. The memory eraser slowly wipes away the past, and this is indeed the most widely recognized face of the disease. Yet what truly leaves countless family caregivers exhausted, hurt, and even at their breaking point is often not the "forgetting" — it's the "changing."

 

The once gentle and loving father suddenly insists that his daughter-in-law stole his bankbook. The mother who cared about appearances her whole life begins to grow restless and pace back and forth at dusk, even arguing heatedly with empty air. In medicine, these behaviors have a specific name: the behavioral and psychological symptoms of dementia, abbreviated as BPSD. They include agitation, apathy, suspicion, hallucinations, aggressive behavior, and disruptions of the sleep-wake cycle.[1]

 

Understanding the true nature of these symptoms is the most important lesson on the caregiving journey. These behaviors do not mean the person has "turned bad," nor are they "picking a fight on purpose." They are instinctive reactions of a damaged brain trying to make sense of a world that has become strange and frightening.

When the Delusion of "Being Robbed" Strikes: Suspicion and Delusions

"My gold ring is missing — you must have taken it!" When faced with such an accusation, a caregiver's first reaction is often hurt and anger. But the Alzheimer's Association notes that this kind of suspicion and delusion is quite common in the middle and late stages of the disease. Because of declining memory, the person may genuinely have forgotten where they put something, and to fill in this "memory gap," the brain automatically constructs a seemingly reasonable explanation: since it can't be found, someone must have taken it.[2]

 

At this point, arguing is the most ineffective — and even harmful — strategy. The more you present evidence to prove "I didn't take it," the more the person becomes convinced you are making excuses, and the conflict escalates. Authoritative organizations advise: do not argue, and do not try to persuade with logic. Instead, first validate the emotion: "The ring is missing — you must be so worried. Let's look for it together." Then gently redirect attention to something else, such as asking them to help fold towels or suggesting a walk outside. Another highly practical tip is to prepare replacements: if the person constantly can't find their wallet and accuses others, buy an identical spare and "produce" it when they become anxious. This is not deception — it is a gentle safeguard for their sense of security.

 

The Storm at Dusk: Sundowner's Syndrome

Many families notice a strange pattern: as soon as evening comes or it gets dark, the person becomes noticeably more irritable and anxious, and may even experience hallucinations and aggressive behavior. In medicine, this is called "sundowner's syndrome." According to Mayo Clinic, it may be related to disruptions in the body's biological clock, physical and mental fatigue at the end of the day, and fear triggered by the increased shadows as light dims.[3]

 

To manage sundowner's syndrome, lighting is the first line of defense. Before evening arrives, turn on all the lights in the house to eliminate dim corners and unsettling shadows. At the same time, try to keep daytime activity routines consistent and avoid long afternoon naps — keep naps to no more than half an hour. If possible, take the person outdoors in the morning to get sunlight, as natural light helps recalibrate a disrupted biological clock. When the dusk agitation hits, don't try to reason with them by saying "it's dark now, time to calm down." Instead, play their favorite song from their youth, or hand them a pile of laundry to fold. Simple, repetitive actions often have a remarkably soothing effect.

The Overlooked Trigger: Physical Discomfort

Before attributing every behavioral problem to "the brain going bad," there is one extremely important yet often overlooked step: Are they uncomfortable somewhere?

 

Authoritative medical resources clearly state that pain, constipation, urinary tract infections — even a room that is too hot or too cold — can all be direct triggers of agitation and aggressive behavior. The predicament of a person with Alzheimer's is that they feel the discomfort but have lost the language ability to accurately express "my stomach hurts" or "I'm terribly constipated." This unspoken suffering can ultimately only be vented through irritability, refusal to cooperate, or even hitting.[4]

 

Therefore, when a usually calm elder suddenly becomes irritable, first do a "physical check": Have they had a bowel movement recently? Are there signs of fever or frequent urination? Is their clothing too tight? Is there tenderness in the joints? Non-pharmacological intervention always comes first, and ruling out physical discomfort is the most basic — and most easily skipped — step within it.

 

A Required Course for Caregivers: Go Easy on Yourself

Finally, a few words for every caregiver reading this. When faced with accusations, verbal abuse, or even pushing from a loved one, it is impossible not to feel hurt. But please remind yourself again and again: these words do not come from the person who loves you — they come from the disease.

In its advice to caregivers, the Alzheimer's Association writes: "Don't take it personally. Remember that the disease is causing these behaviors." This is not asking you to suppress your emotions, but rather to give you one more perspective to hold onto in the moment you are stung. You don't need to be a perfect caregiver — you only need to be a caregiver who understands that "he is sick."[2]

 

When the storm passes, he may forget everything that just happened — but you deserve to be treated with gentleness. Seeking rotation among family members, using community day-care resources, or even just venting to a friend for half an hour — none of these are signs of weakness. They are necessary strategies for making the caregiving journey last.

 

 

 

[1]Lee, H. H., et al. (2025). Behavioral and psychological symptoms (BPSD) in Alzheimer‘s disease (AD): Development and treatment. Current Topics in Behavioral Neurosciences.

https://pubmed.ncbi.nlm.nih.gov/39853561/ 

 

[2]Alzheimer‘s Association. (n.d.). Suspicions and delusions.

https://www.alz.org/help-support/caregiving/stages-behaviors/suspicions-delusions

 

[3]Mayo Clinic. (2024, October 29). Alzheimer’s: Managing sleep problems

https://www.mayoclinic.org/diseases-conditions/alzheimers-disease/in-depth/alzheimers/art-20047832

 

[4]National Center for Biotechnology Information. (2024). Behavioral and psychological symptoms in dementia. NCBI Bookshelf.

https://www.ncbi.nlm.nih.gov/books/NBK551552/