Dementia is a group of conditions that cause a decline in cognitive functioning, which includes thinking, remembering, and problem-solving. The most common form of dementia is Alzheimer’s disease.

Symptoms of dementia include memory loss, difficulty expressing thoughts, and becoming confused or disoriented. Some people with dementia may become aggressive at times and have trouble regulating their emotions.

Psychosis can also be a complication of dementia. Psychosis refers to the mental state where someone is not sure what’s real or not. It can include paranoid or delusional thoughts as well as hallucinations.

Managing and treating dementia-related psychosis requires understanding, patience, and a variety of different approaches. We’ll go over what researchers know so far about why this symptom occurs in dementia, and how it can be addressed.

Approximately 5.8 million people in the United States have recevied a diagnosis of dementia. Researchers believe that number will double by 2060. A significant portion of people with dementia will likely experience psychosis at some point.

Rates of dementia-related psychosis depend on several issues, such as:

  • type of dementia
  • stage or severity of dementia
  • individual risk factors, including other health conditions

One 2021 study indicates 20 to 70 percent of people with dementia will experience psychosis as part of the condition.

Another study from 2020 suggests that 90 percent of people with dementia have some kind of behavioral and psychological symptoms, including psychosis, agitation, aggression, and depression.

While psychosis can occur with any type of dementia, some types of dementia have higher rates. These include Alzheimer’s disease, Lewy body dementia, and dementia related to Parkinson’s disease.

Psychosis may become more likely as dementia advances and other symptoms become more severe.

However, in some people, psychosis may be an early symptom of dementia. Hallucinations may occur during the early impairment stage. They could even develop before any other symptoms.

Psychosis symptoms often depend on the type of dementia a person has. Their overall health and complicating risk factors may also impact how symptoms develop. In short, each person’s experience will be different.

Symptoms of dementia-related psychosis may include:

For example, a person with dementia might hallucinate a cat or dog that is not really in the room. They might have a delusion or paranoia that their caretaker is stealing money or trying to harm them, even if there is no evidence of this.

It’s unclear what causes some people with dementia to develop psychosis but not others. However, a few potential causes have been identified.

In people with Alzheimer’s disease, atypical deposits on the brain may be related to psychosis. These can interfere with the brain’s signaling. People with Alzheimer’s disease are more likely to experience delusions.

Lewy body dementia is the result of plaque deposits or “Lewy bodies” on the brain. They impact the brain’s chemical messaging system. Visual hallucinations are a common symptom of psychosis in people with this type of dementia.

Dementia related to Parkinson’s disease could be connected to medications. People with Parkinson’s disease often take dopamine-enhancing medications for some symptoms, including stiffness and walking issues. However, some of these medications may cause the onset of psychosis symptoms.

But in many people, dementia-related psychosis is the result of ongoing changes to the brain, many of which cannot be identified or stopped.

There is no standardized treatment for dementia-related psychosis. Psychosis is a complicated phenomenon that does not have a simple cure.

Instead, doctors may rely on caregivers to help the affected person with dementia understand what they’re experiencing. Certain strategies can limit potential triggers for psychosis and prevent stressful, emotional situations from getting out of control.

These strategies may include:

  • Adjusting the environment. If someone with dementia has recurring symptoms of psychosis, it may help to eliminate any potential triggers for those experiences.
    • For example, if they “see” other people in the room after catching a glimpse of themselves in the mirror, cover reflective surfaces.
    • If dark, shadowy corners of the house worry them, use lights to illuminate these spaces.
    • The National Institute on Aging also suggests decluttering the home environment, making it easy to navigate, and labeling items to help make people with dementia feel more secure.
  • Adjusting your caregiving approach. Challenging someone’s delusions or hallucinations can make them angry, scared, and even aggressive. Instead of trying to tell someone that something is not real, caregivers may instead engage with their loved ones by asking questions. Try not to raise your voice or yell.
  • Keeping active. Leaving a person with dementia alone all day is not healthy. Instead, people with dementia should be active and engaged regularly. Plan walks, have loved ones visit, or work on simple tasks around the house.

In more advanced cases, doctors may prescribe medication for dementia-related psychosis.

Medications currently being studied and prescribed off-label for dementia-related psychosis include, among others:

  • serotonin 5-HT-receptor agonists
  • selective serotonin reuptake inhibitors (SSRIs)
  • atypical antipsychotics (brexpiprazole, lumateperone, or pimavanserin)
  • second generation antipsychotics (especially quetiapine)
  • lithium
  • anticonvulsants (gabapentin)
  • cannabinoids (THC and CBD, substances found in the cannabis plant)

The antipsychotic pimavanserin (brand name Nuplazid) is approved by the Food and Drug Administration to treat psychosis in Parkinson’s disease.

These drugs are not without side effects. Some medications run the risk of worsening psychosis symptoms or increasing death rates in those with dementia.

Psychosis vs. sundowning

Sundowning refers to a worsening of cognitive and behavioral dementia symptoms that happen later in the day. Sundowning does not necessarily include symptoms of psychosis, but it can be a factor.

Strategies for managing sundowning are similar to those for dementia-related psychosis.

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Dementia-related psychosis can be difficult to diagnose. Symptoms may be mistaken for other health conditions, such as anxiety and depression. People with dementia may conceal some of their symptoms and be hesitant to admit they’re seeing or hearing things others aren’t.

While psychosis is common in people with the memory-related conditions, there are few effective medical treatments. Lifestyle adjustments, caregiving, and certain medications can help manage episodes of dementia-related psychosis.

Understanding that many people with dementia experience some symptoms of psychosis and learning how to recognize those signs may help affected people and caretakers prepare.

It also encourages compassion and understanding as loved ones and medical professionals sort through the impacts of psychosis and how it interacts with other symptoms of dementia.