What Is Dementia-Related Psychosis?

Medically Reviewed by Neha Pathak, MD on March 09, 2021
5 min read

More than 2 million Americans have dementia-related psychosis. If you have a loved one who has dementia, you know that it can be a scary condition -- for both those going through it and for their caregivers. When they have to deal with psychotic episodes, too, it can be even more unnerving.

"But instead of thinking psychotic features as this taboo, icky subject, I just want people to understand that it's a normal manifestation of these illnesses. An expected manifestation. A disease talking," says Pierre N. Tariot, the director of the Banner Alzheimer's Institute in Phoenix, AZ.

"Your loved one is not 'crazy.' They're ill. Their brain isn't functioning properly. And we can evaluate that, and we can help you understand that. And we can help relieve the distress -- yours and your loved one's."

To understand dementia-related psychosis, it helps to break down the terminology:

Some experts now refer to dementia as "neurocognitive disorder." But doctors still use the word dementia. It's a broad term that encompasses a wide range of conditions caused by changes in the brain.

Alzheimer's disease is, perhaps, the best-known form of dementia. But there are others, including:

  • Lewy body dementia
  • Frontotemporal dementia
  • Vascular dementia

These conditions include a decline in thinking and problem-solving that often makes daily life and independent living difficult.

Common symptoms of dementia include:

  • Memory lapses (forgetting the name of a loved one, for example)
  • A waning attention span
  • A hard time communicating (using unusual words, for example, to refer to familiar objects)

Broadly, psychosis is when a person has trouble figuring out what is real and what is not. People with psychosis may have delusions, like a firm, false belief that someone's trying to kill them. They could also have hallucinations -- seeing or hearing something or someone that others don't.

"There's a tremendous lack of understanding and knowledge about these terms," says Gary Small, MD, the director of the UCLA Longevity Center. "Those terms are scary. Dementia sounds pejorative. And a term like psychosis or psychotic is scary, too.

"What I try to do is explain what those things are, what those phenomena are, and try to help them understand it."

As the term might suggest, people with dementia-related psychosis have the decline in thinking and problem-solving skills of dementia, as well as delusions or hallucinations of psychosis. (Delusions are more common.)

All of that can trigger other problems, like:

  • Apathy
  • Anxiety
  • Aggression
  • Sleeplessness
  • Agitation
  • Lack of inhibition


The first step in finding out if your loved one has dementia-related psychosis is making sure that a hallucination or delusion isn't the result something else. A uterine tract infection, for example, can lead to hallucinations.

Diagnosing dementia-related psychosis is mainly about gathering information; ruling out other causes; and then observing, listening, and asking questions.

"What I do is, I never see [people] by themselves," says George Grossberg, MD, the director of geriatric psychiatry at the Saint Louis University School of Medicine. "I always see them at least with one or more -- but at least with one -- personal caregiver or care partner. Usually, it's a spouse or an adult child.

"I ask them questions about what kinds of things they're noticing with the loved ones with dementia."

What could those questions be?

"I might say, 'It's been about 3 or 4 months since we've seen you and Mom. How are things going?

"'Have you or she noticed anything unusual or different?

"'Has Mom maybe either heard or seen things or imagined things that you're concerned about because you don't see or hear or imagine them?'

"And that opens up kind of a whole area for them to talk."

It's not always easy. Those with dementia may hide their symptoms, for fear of the stigma that often comes with mental health problems. Others -- nurses, doctors, professional caregivers -- may not pick up on the signs for a variety of reasons. That makes observing, talking, and asking the right questions -- for everyone involved -- even more important.

"I tell all my trainees, the medical students and residents, 'This is detective work,'" says Zahinoor Ismail, MD, the principal investigator at the Ron and Rene Ward Centre for Healthy Brain Aging Research at the University of Calgary.

"You have to look, and you actually have to ask for information from all the sources."

There's no cure for Alzheimer's and other dementias. So the first line of treatment for dementia-related psychosis isn't drugs or medicine.

In fact, sometimes people with milder psychosis may not need treatment. If a hallucination or a delusion doesn't bother the person with dementia, there's often no need to treat it. If it does bother them, some simple methods -- like making sure that the environment around the person with dementia doesn't trigger the episode -- can help.

Tariot recalls a woman with dementia who believed someone was in the room with her. In fact, the woman had caught a glimpse of her own reflection. Covering up a mirror lessened her anxieties. In another case where a person thought someone was spying on them, Small says lowering a window shade eased the trouble.

Also effective for some with dementia: Just getting their minds off an episode that may upset them.

"The best way to respond is in a calm way, to distract people," Small says. "I often remind them about what it was like when their kids were rambunctious and young. You'd redirect them, with a game to play, or so forth and so on."

If those kinds of methods don't work, doctors may opt to prescribe medication. The FDA hasn't approved any drugs specifically for dementia-related psychosis. Instead, doctors often go "off-label" to prescribe antipsychotic medicines that aren't specifically for dementia-related psychosis.

"Where [methods that involve drugs] don't work, we do resort to medications. The problem is the medications we've had available … they just don't work very well," Tariot says. "They have, at best, about a 1-in-5 chance of helping enough to notice, and about an 80 or 90 percent chance of causing harm."

Psychosis with dementia can be challenging to diagnose and to treat. But understanding it, realizing its effects on both the person with dementia and those around that person, and using care and compassion in treating it can make things much better for everyone involved.

"I have people ask me all the time, 'Gee, Dr. Grossberg, I know you specialize in Alzheimer's disease. How do you do it? Don't you get depressed? Don't you get despondent?'" Grossberg says.

"And I say, 'No. Just the opposite.' There's a lot that we can do to really improve the quality of life for the [person] and the care partners, to really make whatever remaining days they have left more pleasant and more comfortable. That gives me a lot of satisfaction."