Paranoia and delusions in dementia patients

Naomi Carr
Author: Naomi Carr Medical Reviewer: Morgan Blair Last updated:

People with dementia typically experience memory loss and impaired cognitive function. It is not uncommon for dementia to also cause psychological changes, which can include paranoia and delusions. These symptoms can be distressing and challenging but can be managed with therapeutic interventions and, occasionally, with medications.

What are paranoia and delusions?

Delusions are strongly held beliefs or ideas that are not based on reality and logic. Examples of delusions could include thinking that a person on the television is sending you special messages or that you are best friends with the King of England [1].

Paranoia or paranoid delusions are based on ideas of persecution, with the false belief that someone, something, or a group are a threat to wellbeing or safety. These ideas can result in the individual becoming very suspicious of everyone around them and can cause a great deal of distress [1][2].

Someone with dementia may experience paranoia and delusions due to their condition. Some example of how this may present include thinking that a nurse who is trying to give them medication is trying to poison them, or that a relative who is visiting them is trying to steal their jewelry [3].

What causes delusions in dementia?

Delusions can occur in the context of several different conditions, such as schizophrenia and bipolar disorder, as well as being a potential symptom of various forms of dementia [1].

Brain changes that occur in dementia patients contribute to reduced brain volume and matter, as well as reduced level of certain neurotransmitters, such as dopamine, acetylcholine, and glutamate. These changes are believed to contribute to behavioral and psychological symptoms of dementia, including delusions and paranoia [4][5].

Furthermore, dementia causes cognitive impairment, such as memory loss, difficulties with problem-solving, and a decreased ability to understand and process information. Impaired cognitive functioning causes confusion surrounding certain circumstances and situations, potentially leading to suspicion of others and then forming false beliefs or conclusions [6].

For example, an individual may forget where they put a certain item and, instead of being able to consider that they lost or misplaced it, may believe it was stolen. Similarly, a person with dementia may have an impaired ability to recognize others, leading them to believe that a caregiver or relative is a stranger, causing suspicion or fear of this person.

Medical conditions can also contribute to the development of delusions, such as impaired hearing or sight. Physical impairments may cause a person to misinterpret a situation and form paranoid ideas and delusions. Similarly, delirium caused by medical issues such as infections can cause delusions and hallucinations and may require urgent medical attention [3][7].

Signs of paranoia and delusions

Typically, signs of paranoia and delusions in dementia will emerge gradually and continue to worsen as the condition progresses. However, if these signs appear suddenly, or rapidly worsen in a short time, it may be an indication of delirium, so professional assistance should be sought immediately [7].

Signs of paranoia and delusions in an individual with dementia can include [3][7][8]:

  • Accusing people of stealing from them
  • Regularly being afraid or suspicious of people, even people they know such as caregivers or relatives
  • Saying that people they know are strangers or have been replaced by an imposter
  • Becoming concerned that they are in a strange or unusual environment despite being in their own home
  • Calling the police for assistance
  • Accusing their partner or spouse of being unfaithful
  • Accusing caregivers or relatives of attempting to harm or poison them
  • Stating that they need to attend school or work

It is important to bear in mind that there may be people stealing from, harming, or exploiting older adults with dementia. There may be circumstances in which their concerns require investigation to ensure their safety, so should not immediately be considered delusions or paranoid beliefs.

At what stage of dementia are paranoia and delusions common?

The stage at which paranoia and delusions occur may vary depending on the type of dementia. For example, in Alzheimer’s disease, these symptoms become more likely as the condition progresses, more often occurring in the middle to late stages [4][6].

However, in Lewy body dementia, there is a high prevalence of symptoms of psychosis, particularly visual hallucinations and delusions, which can begin in the early stages and become progressively worse.

Parkinson’s disease dementia, which shares similar characteristics to Lewy body dementia, also commonly causes symptoms of psychosis in the early stages. Hallucinations are more common than delusions in this condition, but the most common delusions are of a paranoid nature [6].

How long do paranoia and delusions last?

If delusions and paranoia are caused by delirium, medication, or other medical issues, then they can be reduced with treatment in a short period of time. However, if they are experienced as a symptom of dementia, then they are likely to continue throughout the progression of the illness, potentially worsening with time as the condition causes further degeneration [4].

Since individuals with dementia have an impaired ability to problem-solve and understand information, delusions are unlikely to change with time or attempts at logical reasoning. As such, delusional beliefs will remain in place, but can be made less prevalent or distressing with therapeutic relationships and changes to the environment [1][8].

How to manage paranoia and delusions in people with dementia

Delusions and paranoia occurring in people with dementia should first be attempted to be managed without the use of medication. There are several techniques and interventions that can be utilized to help with this, such as [3][6][7][8]:

  • Acknowledge distress: Although it may be clear to others that these delusions or paranoid thoughts are not real, they can feel very real to the individual with dementia, so it is important to acknowledge and empathize with their experience, demonstrate support, and ask how to help them in the situation.
  • Don’t argue with delusions: It is unlikely that the individual will be able to listen to reasoning and logic to change their belief, due to the nature of their condition and impairments, so attempting to prove that they are wrong will likely lead to distress and mistrust and potentially damage therapeutic relationships.
  • Ask them to explain: There may be a reason for the delusion or paranoid idea that can be managed, or there may be a possibility to offer an alternative idea for them to consider, potentially reducing their distress without contradicting their experience.
  • Mitigate the causes: If a specific issue or circumstance is contributing to a delusion or paranoid behavior, such as a specific food, environment, people, or noises, changes can be made to help reduce the individual’s associated distress.
  • Utilize distractions: If after discussing, empathizing, and reassuring, the intensity of the delusion or idea persists, it may be useful to distract the individual, such as by moving into a different environment, engaging in a new topic of conversation, or putting on a TV show they enjoy.
  • Placement of photos: Having several photographs in the home of friends and family members can help reduce or prevent confusion and delusions around recognizing people, places, and time.
  • Maintaining routines: Having a consistent routine, set places for items to be kept, and a familiar and unchanging environment can help prevent confusion and paranoia around situations, locations, and misplaced items.
  • Maintaining physical health: Several medical issues can contribute to the occurrence of delusions and paranoia, such as impaired hearing, eyesight, and dental health, as well as infection-related delirium, so having regular check ups and maintaining general health can help to reduce these risks.


Antipsychotic medications can be prescribed if delusions and paranoia become severe, unmanageable, or create a risk of harm to the individual or others. Non-drug interventions should be utilized first, with medications only being used if absolutely necessary and with careful monitoring of physical wellbeing, as they can increase the risk of serious side effects, stroke, and death in older adults with dementia [5][6].

  1. Kiran, C., & Chaudhury, S. (2009). Understanding Delusions. Industrial Psychiatry Journal, 18(1), 3-18. Retrieved from
  2. Mind. (2020). Paranoia. Mind. Retrieved from
  3. Alzheimer’s Society. (Reviewed 2021). Delusions, Paranoia, and Dementia. Alzheimer’s Society. Retrieved from
  4. Urso, D., Gnoni, V., Filardi, M., & Logroscino, G. (2022). Delusion and Delirium in Neurodegenerative Disorders: An Overlooked Relationship? Frontiers in Psychiatry, 12, 808724. Retrieved from
  5. Cloak, N., & Al Khalili, Y. (2022). Behavioral and Psychological Symptoms in Dementia. In StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing. Retrieved from
  6. Alzheimer’s Association. (2023). Suspicions and Delusions. Alzheimer’s Association. Retrieved from
  7. Dementia UK. (2023). False Beliefs and Delusions in Dementia. Dementia UK. Retrieved from
  8. National Institute on Aging. (Reviewed 2017). Alzheimer’s and Hallucinations, Delusions, and Paranoia. NIH. Retrieved from
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Naomi Carr
Author Naomi Carr Writer

Naomi Carr is a writer with a background in English Literature from Oxford Brookes University.

Published: May 16th 2023, Last edited: Sep 22nd 2023

Morgan Blair
Medical Reviewer Morgan Blair MA, LPCC

Morgan Blair is a licensed therapist, writer and medical reviewer, holding a master’s degree in clinical mental health counseling from Northwestern University.

Content reviewed by a medical professional. Last reviewed: May 16th 2023