Dementia of the Alzheimer’s type with delusions is a challenging condition where people experience false beliefs that feel completely real to them, alongside the memory and thinking problems caused by Alzheimer’s disease. These delusions can create fear, confusion, and distress for both the person living with the condition and their loved ones.
Understanding Delusions in Alzheimer’s Disease
When someone has Alzheimer’s disease, their brain undergoes complex changes that affect much more than just memory. Delusions are false beliefs that the person firmly holds as true, even when presented with evidence to the contrary. Unlike forgetting where you placed your keys, delusions involve believing something entirely different from reality, such as thinking that family members are strangers or that someone is stealing from you, when neither is actually happening.[1]
These experiences are not something the person can simply talk themselves out of or choose to stop believing. To the person experiencing them, these beliefs feel completely real and true. A common type of delusion in Alzheimer’s disease is paranoia, where the person becomes suspicious, fearful, or jealous of others without good reason. They might believe others are mean, lying, unfair, or trying to harm them.[3]
It’s important to understand that delusions differ from hallucinations, though both can occur in dementia. While hallucinations involve seeing, hearing, smelling, tasting, or feeling things that aren’t actually there, delusions are firmly held false beliefs about reality. Both can be frightening and confusing, but they represent different ways the brain is being affected by the disease.[4]
How Common Are Delusions in Alzheimer’s Disease?
Delusions are surprisingly common among people living with Alzheimer’s disease and other forms of dementia. Research shows that delusions are present in approximately 15 to 75 percent of patients with Alzheimer’s disease, depending on the study and stage of disease. Nearly half of all people living with any form of dementia, including Alzheimer’s disease, can experience delusions at some point during their illness.[13][21]
Approximately 30 percent of patients with Alzheimer’s disease experience symptoms of psychosis, which commonly consist of hallucinations and delusions. These symptoms may be frequent and severe and can recur over time throughout the course of the illness.[16]
The nature and frequency of these symptoms vary over the course of the illness. Psychotic features, including delusions, tend to develop mostly in the middle to later stages of dementia, particularly when the person becomes more dependent on others for care. In the early stages of Alzheimer’s disease, people may experience behavior and personality changes such as irritability, anxiety, and depression. As the disease progresses into later stages, delusions become more likely to appear alongside other symptoms.[13][11]
Why Do Delusions Happen?
Delusions in Alzheimer’s disease result from neuropathological changes in the brain—in simpler terms, the progressive damage and death of brain cells. As Alzheimer’s disease progresses, it causes the brain to lose its ability to properly process and interpret information from the world around it. This leads to confusion and false beliefs that can seem completely logical to the person experiencing them.[4][7]
Memory loss plays a significant role in how paranoia and delusions develop. When someone with Alzheimer’s forgets where they put something, they may truly believe someone has stolen it because they cannot remember placing it somewhere themselves. Similarly, when they forget who a caregiver is, that person may seem like a threatening stranger. When they can’t remember directions they were just given, they might believe someone is trying to trick them. The person may blame or accuse others because no other explanation seems to make sense to them in that moment.[3]
Dementia causes the brain to misinterpret the information it receives from the senses and from memory. The frontal lobes of the brain, located right behind the eyes, control our ability to focus, stay motivated, and manage impulses. When cells in these areas are lost due to Alzheimer’s disease, people become less able to plan, stay focused, and control their responses to situations. This can lead to behaviors and beliefs that seem out of character, including suspicions and false beliefs about what is happening around them.[8]
Strong emotional memories from a person’s past may re-emerge as delusions in dementia. The person may have trouble separating past experiences from current reality and may re-live these events to a certain extent, creating beliefs based on confused memories rather than present circumstances.[7]
What Other Factors Can Contribute to Delusions?
While Alzheimer’s disease itself is the primary cause of delusions, several other factors can trigger or worsen these symptoms. Understanding these contributing factors is important because some can be addressed or managed to reduce distress.[4]
Physical health problems can play a role in causing or worsening delusions. Infections, fever, constipation, anemia, respiratory disease, and dehydration can all contribute to confusion and false beliefs. Sometimes an illness or medication side effect may cause hallucinations or delusions to appear suddenly or become worse. This is why it’s important to discuss any new or worsening symptoms with a doctor who can evaluate for underlying medical causes.[3][4]
Environmental factors matter as well. Poor eyesight or hearing problems can lead to misunderstandings about what is happening around the person. New or changed environments, different caregivers, or disrupted routines can trigger feelings of confusion and fear. Being overwhelmed by too many things happening at once, such as noise, conversation, crowds, or activity, may be over-stimulating and too difficult for the person to process or understand.[4][8]
Mental health conditions can also contribute. In some cases, existing mental health conditions such as depression or anxiety may worsen delusions. However, it’s important to note that delusions in dementia are distinctly different from those in psychiatric conditions like schizophrenia, even though they may sometimes appear similar.[4]
Common Types of Delusions in Alzheimer’s Disease
Delusions in Alzheimer’s disease often follow recognizable patterns. One of the most common forms is the belief that someone is stealing personal belongings. This happens because when the person forgets where they placed something, they truly believe it has been taken. The accusation is their way of trying to make sense of the missing item.[1][3]
Another common pattern involves suspicions about family members or caregivers. A person with Alzheimer’s may become suspicious of those around them, even accusing others of theft, infidelity, or other improper behavior. They might believe their spouse is unfaithful or that a trusted family member is trying to harm them. While these accusations can be deeply hurtful, it’s important to remember that the disease is causing these beliefs, not actual events.[1]
Delusional misidentification is another pattern that occurs in at least 30 percent of patients with dementia. This involves wrongly identifying yourself or other people. For example, someone might not recognize a person they know well, might think their reflection in a mirror is someone else, or might believe that voices from the television are coming from people in the room. They may mix people up or believe family members are impostors who look like their loved ones but aren’t really them. This is sometimes called Capgras syndrome, where patients suspect that their family members are impostors.[4][13]
How Delusions Affect Daily Life
The impact of delusions extends far beyond the false beliefs themselves. These symptoms can lead to significant consequences for both the person with Alzheimer’s disease and their caregivers. For the person experiencing delusions, feelings of fear, anxiety, anger, frustration, or distress are common. They may feel genuinely threatened or betrayed, which can be terrifying.[3]
Serious consequences have been associated with psychosis in patients with Alzheimer’s disease. These include increased likelihood of placement in a nursing home, more severe progression of dementia, and increased risk of health problems and mortality. The presence of hallucinations and delusions can predict a greater likelihood of progression to severe dementia.[16]
Delusions can make everyday care activities much more difficult. The person may refuse care, resist taking medication, or become aggressive when caregivers try to help with bathing, dressing, or eating. When someone believes their caregiver is a threatening stranger, they naturally resist that person’s attempts to provide care.[1]
For family members and caregivers, these symptoms may be more troubling and challenging than the memory loss itself. These behavioral features result in an increased burden for caregivers, contributing to stress, exhaustion, and emotional pain. It can be heartbreaking to be accused or distrusted by someone you love. Over time, these patterns may strain relationships and make maintaining care at home increasingly difficult.[13][16]
How the Brain Changes Lead to Delusions
To understand why delusions happen, it helps to know a bit about what’s happening inside the brain. Alzheimer’s disease causes progressive deterioration of brain cells, particularly in areas that control memory, thinking, and perception. This cellular damage disrupts the brain’s normal ability to process information accurately.[11]
The disease affects parts of the brain involved with learning, memory, decision-making, and language. When these areas are damaged by the buildup of abnormal proteins and the death of nerve cells, the person loses the ability to accurately interpret their environment and their memories. What they perceive or remember becomes distorted, leading to false beliefs that feel completely true to them.[5]
Dementia also alters how a person responds to their environment. Someone with Alzheimer’s disease may be forgetful and have trouble following conversations. They may become angry and frustrated because they cannot follow what is going on. Many people with dementia also rely on others for emotional cues, mirroring the emotions of those around them. If caregivers are anxious and worried, many people with dementia will mirror those emotions and become anxious and worried themselves.[8]
Behavior changes happen for many reasons in dementia, usually because the person is losing neurons in specific parts of the brain. The behavior changes you see often depend on which part of the brain is losing cells. This explains why different people with Alzheimer’s disease may develop different types of delusions or behavioral symptoms based on how the disease is affecting their unique brain structure.[8]
How to Respond When Delusions Occur
Responding effectively to delusions requires patience, understanding, and specific strategies that acknowledge the person’s experience while keeping them safe. The first and most important step is to tell the person’s doctor about the delusions. Discuss any illnesses the person has and medicines they are taking, as sometimes an illness or medication may cause or worsen hallucinations or delusions.[3]
Do not argue about what the person with Alzheimer’s believes. Trying to convince them that their delusion isn’t real rarely works and often makes the situation worse. Delusions feel completely true to the person experiencing them, and it’s usually not possible to convince a delusional person that their belief isn’t true, even if it seems bizarre or impossible to others. Instead of arguing, acknowledge the person’s feelings and offer comfort if they are afraid.[3][4]
Distraction can be a powerful tool. Sometimes moving to another room or going outside for a walk helps redirect attention away from the false belief. Focusing on a photo, keepsake, or engaging activity can help shift the person’s thoughts to something more positive.[3]
When responding to paranoia or suspicion, it’s important to stay calm and be patient. Remind yourself that dementia is a brain disease manifesting symptoms, and what you’re witnessing is not intentional behavior directed at you personally. Avoid arguing with the person about what they believe they see, hear, or feel.[7]
Acknowledge the person’s feelings and respond to the emotions behind their words. For example, if someone is frightened by a delusion, you might say something like, “I’m so sorry, that’s a scary feeling. Let’s take a deep breath. Come with me, let’s make sure everything is okay.” This validates their emotional experience without reinforcing the false belief.[7]
If the person is feeling afraid, offer comfort in a respectful way. Gentle touching, such as holding a hand, hugging, or rubbing their back can help. Let them know they are safe. Simple, reassuring words can make a significant difference in reducing distress.[7]
Make sure the person is safe and cannot reach anything they could use to hurt themselves or anyone else. Check the environment carefully for anything that might be triggering the delusion, such as disturbing images on television, shadows, reflections, or noises. Turn off the television when violent or upsetting programs are on, as someone with Alzheimer’s may think these events are actually happening in the room.[3]
Non-Medical Approaches to Managing Delusions
Before considering medication, several non-pharmacologic interventions can be effective in managing delusions and related behaviors. These approaches may be used in most patients with dementia-related behavior disorders and are important whether or not medication is also being used.[13]
Creating a calm, structured environment helps reduce confusion and anxiety that can worsen delusions. Maintain consistent routines for meals, exercise, and sleep. Predictability helps the person feel more secure and less likely to become suspicious or fearful. Avoid making sudden changes to the environment or daily schedule when possible.[11]
Make sure family members and caregivers understand that suspicions and false beliefs are symptoms of the disease, not intentional accusations or behaviors. This understanding can help caregivers respond with more patience and less personal hurt when accusations occur.[1]
Address sensory needs appropriately. Make sure the person is wearing their glasses or hearing aid if they use these devices. Poor eyesight or hearing can contribute to misunderstandings and false beliefs about what is happening. Ensure adequate lighting to reduce confusing shadows, but avoid harsh or flickering lights that might be disturbing.[4]
Observe the person’s environment for any noises, shadows, or objects that could be triggering fear or confusion. Sometimes a simple environmental change, like covering mirrors or adjusting curtains, can reduce distressing delusions.[7]
Behavior modification techniques, appropriate use of sensory interventions, environmental safety measures, and maintenance of daily routines all contribute to reducing the frequency and intensity of delusions. These approaches work by reducing triggers and creating a more understandable, less threatening environment for the person with dementia.[3]
Medical Treatment Options
When non-medication approaches aren’t sufficient to manage delusions, doctors may consider pharmacologic treatments. Currently, there is no medication specifically approved by the FDA for the treatment of Alzheimer’s disease psychosis, though this is an active area of research.[16]
Atypical antipsychotics are medications that have shown the greatest effectiveness and are generally best tolerated for managing psychotic symptoms in dementia. These medications work by affecting brain chemicals involved in perception and thought. Studies focusing on the management of delusions in patients with Alzheimer’s disease have identified atypical antipsychotics as one of the main categories of treatment.[13][14]
Risperidone and haloperidol are the only medicines currently licensed for people with moderate to severe Alzheimer’s disease where there’s a risk of harm to themselves or others. Risperidone should be used at the lowest dose and for the shortest time possible with regular reviews at least every six weeks. These medications can cause side effects, and haloperidol can be used only if other treatments have not helped.[17]
The decision to prescribe medication for delusions should be taken by a consultant psychiatrist after careful evaluation. Pharmacologic treatments should follow a “start low, go slow” philosophy, meaning doctors begin with the lowest possible dose and increase it gradually only as needed. A monosequential approach is recommended, in which a single agent is adjusted until the targeted behavior is reduced, side effects become intolerable, or the maximum safe dosage is achieved.[13]
Cholinesterase inhibitors, which are medications commonly used to treat Alzheimer’s disease symptoms, have also been studied for their effects on delusions. These medications help prevent the breakdown of acetylcholine, a brain chemical important for nerve cell communication. They are identified as another main category of treatment for delusions in research studies.[14]
Second-line medications that may be considered include typical antipsychotics for short-term therapy, and less often, anticonvulsants, antidepressants, and anxiolytics. However, it’s important to note that non-drug interventions generally should come first, as some medicines can cause negative side effects and actually make things worse.[7][13]
A drug called pimavanserin, which was initially approved in 2016 to treat psychosis in Parkinson’s disease, has shown promise in treating people with various types of dementia who have delusions. Research tested this medication on nearly 400 people with five types of dementia, including Alzheimer’s dementia. While not yet approved for Alzheimer’s disease psychosis, it represents an area of ongoing research.[15]
Goals of treatment should include symptom reduction and preservation of quality of life for both the person with dementia and their caregivers. Medications are only one part of comprehensive care and work best when combined with environmental modifications and supportive care approaches.[13]
Supporting Caregivers
Caring for someone with dementia and delusions places enormous demands on family members and caregivers. The emotional toll of being accused, distrusted, or viewed with suspicion by someone you love can be profound. Caregiver stress, depression, and burnout are real risks that need to be acknowledged and addressed.[11]
Counseling the caregiver about the non-intentional nature of the psychotic features and offering coping strategies are important components of comprehensive care. Understanding that delusions are symptoms of brain disease, not personal attacks, can help caregivers maintain emotional distance from hurtful accusations.[3]
Caregivers need support, education, and sometimes respite care to manage the ongoing challenges of caring for someone with behavioral symptoms. Support groups, either in-person or online, can provide connection with others facing similar challenges. Professional counseling may help caregivers process their feelings and develop effective coping strategies.[1]
It’s important to maintain accurate documentation and communicate with other members of the healthcare team about behavioral issues. Experienced psychologists and social workers on the dementia care team can help evaluate and interpret troubling behaviors and provide guidance for managing them effectively.[7]
