Responding to and Treating Hallucinations in Dementia

Hallucinations in Dementia Can Be Frightening
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What Are Hallucinations?

Hallucinations are inaccurate perceptions of a person's surroundings which involve at least one of the five senses:

  • Visual
  • Auditory
  • Touch
  • Smell
  • Taste

The most common hallucinations are auditory and visual in nature. Some hallucinations are anxiety-provoking and distressing, such as seeing bugs crawling on the walls. Others can be pleasant and reassuring, such as seeing a cuddly puppy sitting in the chair across the room.

Hallucinations, although they're false, appear extremely real to the person experiencing them.

Why Do Some People with Dementia Hallucinate?

Hallucinations can develop in dementia because of the changes in the brain due to the disease. They typically occur in the later stages of Alzheimer's disease and other types of dementia.

While brain changes related to dementia are likely the root cause of hallucinations, there are also other possible causes, including medications, an overly stimulating environment, changes in routine or sundowning, a worsening of agitation and anxiety in the early evening.

Interestingly, some research published in the Journal of Neurology, Neurosurgery & Psychiatry found that hallucinations were associated with a faster rate of cognitive decline in people with Alzheimer's disease as compared to those with Alzheimer's but without hallucinations.

How Common Are Hallucinations in Dementia?

Estimates vary.

Studies have concluded that anywhere from 28 percent to 50% of people with Alzheimer's disease develop hallucinations. The prevalence of hallucinations varies with different types of dementia. Lewy body dementia, for example, causes approximately 80% of its sufferers to experience hallucinations.

Differentiating between Hallucinations and Sensory Misperceptions

One task for the clinician in treating someone with dementia is to discern whether the person has a true hallucination or whether a hearing or visual deficit is preventing him from receiving sensory information clearly and causing him to misinterpret it.

In other words, is the "hallucination" due to a simple visual mistake because the lighting was poor and he couldn't see clearly? Or, is he truly experiencing a hallucination where he's seeing something that is completely absent? Making this determination is important in knowing how to respond appropriately.

How Should You Respond to Hallucinations?

Let's imagine that a patient or a loved one with Alzheimer's disease has been hallucinating about a man outside her window and is feeling frightened and distressed. What can you do to help? How should you respond to her concern?

  • Don't Argue

    For many people with dementia, the hallucination is just as real as our reality, so arguing with the person about it to convince them it's not there is unlikely to be effective. In fact, it may increase her frustration and anxiety because you're simply dismissing her concern.

  • Verify the Truth

    Make sure that there really hasn't been a man near her window. Was there a window washer there today washing the outside of her window? Are there any footprints outside her window? Don't dismiss the possibility until you rule out the possibility that the hallucination truly occurred.

  • Provide Reassurance

    Let your patient that you will stop by her room frequently and that you'll let the security staff know of her concern to ensure her safety.

  • Adjust the Environment

    Show her that the window is locked and pull the shade down. Perhaps a night light would help to reassure her as well. If the hallucination is persistent, perhaps you might even adjust the position of her bed so that she's not facing the window.

  • Maintain Routines

    As much as possible, maintain a routine and consistent staff assignments for a person with dementia who is living in a facility.

  • Use Distractions

    Sometimes, calming music, pet therapy or a walk to a brightly lit room can help lessen the hallucination.

    Are Medications Helpful for Hallucinations in Dementia?

    The key question about whether hallucinations should be treated with medication is this: Are the hallucinations distressing to the individual? Are they negatively affecting her quality of life? If so, it may be appropriate to consider medications to alleviate the hallucinations. If not, there is typically no need to treat the hallucinations.

    If hallucinations are persistent and distressing, physicians will often prescribe an antipsychotic medication with the goal or reducing or eliminating the hallucinations. Antipsychotic medications are often fairly effective at treating hallucinations as well as paranoia and delusions; however, caution must be used with this class of medications because they can cause significant side effects and are associated in a higher rate of death in people with dementia. Of note, Lewy body dementia carries a significantly higher risk of negative side effects from antipsychotic medications.

    Assessing for Delirium as a Cause of Hallucinations

    There are several possible causes of hallucinations in dementia, but one important one is delirium. Delirium is a sudden notable increase in confusion that is often caused by an infection or medications or medication interactions. Someone with dementia who experiences a sudden onset of hallucinations should be evaluated by a physician for possible treatable causes of delirium.


    Alzheimer's Association. Hallucinations and Alzheimer's. Accessed September 21, 2013.

    Alzheimer's Association. Hallucinations, Delusions and Paranoia. September 2012.

    Alzheimer Society. British Columbia. Delusions and Hallucinations. Accessed January 9 2016.

    American Family Physician. 2006 Feb 15;73(4):647-652. Behavior Disorders of Dementia: Recognition and Treatment.

    Journal of Neurology, Neurosurgery & Psychiatry. 2000;69:172–177. Hallucinations, delusions, and cognitive decline in Alzheimer’s disease.

    Lewy Body Dementia Association. Emergency Room Treatment of Psychosis. Accessed September 26, 2013.

    Psychosis in the Elderly. NovaScotia, Canada. Accessed January 9, 2016.