Hallucinations or Paranoia in an Older Adult: What Are the Causes?

Hallucinations in the elderly are often linked to a medical cause such as delirium, medication effects or dementia, and a sudden change in thinking needs prompt evaluation. Other contributors include infection, dehydration, Parkinson disease, vision or hearing loss and poor sleep. Hallucinations or paranoia with confusion, drowsiness, fever or new weakness need urgent care. This article explains the causes, what clinicians look for, safe ways to respond, and when to get help.

Hallucinations or paranoia in an older adult: what is usually going on

Seeing people who are not there, hearing voices, or becoming convinced that family members are stealing or plotting can be frightening for the person and for you. In an older adult, these symptoms can have a medical cause, such as delirium, medication effects or dementia, as well as a psychiatric one. Several factors usually contribute, and the mechanism is not fully understood in every case.

MedlinePlus describes psychosis as a group of symptoms in which a person loses some contact with reality, including hallucinations (sensing things that others do not) and delusions (fixed false beliefs such as paranoia). Psychotic disorders such as schizophrenia are one possible source, but in later life they are a less common explanation than the medical causes below. One symptom alone does not establish any single diagnosis.

Delirium: a sudden change that needs prompt evaluation

Delirium is defined clinically as an acute state of confusion that can develop over hours to days and often fluctuates. Hallucinations and suspicion can be part of it. The person may be sleepy at one moment and agitated the next, or may not follow a conversation as usual.

Common contributors include:

• Infections, such as a urinary tract infection or pneumonia
• Dehydration or poor nutrition
• Low or high blood sugar, or abnormal sodium and other blood salts
• Low oxygen, heart failure or other acute illness
• Recent surgery, hospitalization or anesthesia
• Pain, constipation or urinary retention
• Alcohol use or sudden withdrawal from alcohol or sedatives

Delirium can be a sign of a serious underlying illness, and treating that cause can often improve it. It needs medical evaluation rather than waiting to see if it passes.

Hallucinations or confusion with shaking, sweating, a racing heart or a seizure after someone has recently stopped or cut down alcohol, sedatives or sleeping pills can reflect withdrawal. Withdrawal can be life-threatening and needs emergency care.

Medications and substances

Many prescription and over-the-counter products can cause confusion, hallucinations or paranoia in older adults, especially when several are taken together or kidney function has declined. Examples that clinicians commonly review include:

• Strongly anticholinergic drugs, including some sleep aids and allergy products that contain diphenhydramine
• Opioid pain medicines and benzodiazepines or other sedatives
• Corticosteroids such as prednisone
• Medicines for Parkinson disease, such as dopamine agonists and levodopa, which should be adjusted only by the treating neurologist because stopping them suddenly can be dangerous
• Some bladder medicines and certain antibiotics

Alcohol and cannabis can also affect perception and thinking. MedlinePlus notes that cannabis can cause problems with thinking and, in some people, psychotic symptoms.

If you suspect a medicine is contributing, call the prescriber or pharmacist the same day. Do not stop or change a prescription on your own, since stopping some medicines suddenly (including Parkinson medicines, benzodiazepines, steroids and antidepressants) can itself cause harm. Check with a clinician or pharmacist before adding any over-the-counter sleep or allergy product or other sedative, because many contain diphenhydramine, which can cause or worsen confusion and hallucinations in older adults. Bring every pill bottle, supplement and over-the-counter product to the prescriber or pharmacist for a review of the list.

Dementia and Lewy body disease

Hallucinations and paranoia can occur in several forms of dementia. In Alzheimer disease, suspicion often shows up as accusations of theft or fear that a spouse or caregiver is an impostor, usually alongside memory loss. The consensus diagnostic criteria for dementia with Lewy bodies list well-formed visual hallucinations (for example, seeing children or animals), fluctuating alertness, sleep-related movements and stiffness or slowness as core features, and hallucinations can appear relatively early.

Because the person with dementia may not be able to explain what is happening, new behavior changes can also reflect pain, infection or a medication problem, so a sudden worsening deserves a medical check rather than being attributed to dementia alone. MedlinePlus has practical guidance in its Alzheimer's Caregivers page.

If low mood and thinking problems are both present, our article on depression or dementia and pseudodementia explains why the two can be confused.

Parkinson disease and visual hallucinations

Visual hallucinations are reported in a meaningful share of people with Parkinson disease. Both the disease itself and the medicines used to treat it may contribute. Research using brain imaging has found changes in visual-processing regions in some people with Parkinson disease who have hallucinations. A person with Parkinson disease who develops hallucinations should tell the treating neurologist the same day, who can decide whether any medicine adjustment is appropriate and whether delirium is a possibility. Avoid changing doses without that guidance.

Vision loss, hearing loss and Charles Bonnet syndrome

When vision drops, the brain can sometimes produce images on its own. This is called Charles Bonnet syndrome. People often see patterns, faces or scenes, and many know the images are not real. Hearing loss can likewise be associated with hearing music or voices, and with suspicion when words are misheard. An eye exam, hearing test and updated glasses or hearing aids can be a useful part of the evaluation, though a clinician should still consider other causes.

Sleep loss, stress, isolation and mental health conditions

Poor sleep can worsen suspicion and perceptual changes. A review of sleep and schizophrenia in the NIH-hosted literature describes sleep disturbance as a potentially treatable contributor to psychotic symptoms, although that research is not specific to older adults. Loneliness, bereavement, a recent move, and social stress are also associated with paranoia in research on the wider population, and they can add to the load on an older adult who already has other risk factors.

Primary psychiatric conditions can also appear or continue in later life. These include schizophrenia and related disorders, severe depression with psychotic features, and bipolar disorder. If the person has had these symptoms since young adulthood, see our article on schizophrenia early signs and treatment.

Other medical causes clinicians consider

• Stroke or other brain injury, including a small bleed after a fall
• Seizures, especially those arising from the temporal lobe
• Thyroid disease and low vitamin B12
• Kidney or liver failure
• Brain tumors or infections of the brain, which are much less common than the everyday causes above

What a clinician will usually do

Clinicians combine history, examination and testing. A typical evaluation may include:

• A review of when symptoms began and whether they came on suddenly or gradually
• A full medication and substance review
• Vital signs, an exam, and a check for pain, constipation and urinary retention
• Blood and urine tests, sometimes chest imaging or a heart tracing
• Vision and hearing screening
• Cognitive testing, delirium screening such as the Confusion Assessment Method (which helps separate delirium from dementia), and, when appropriate, brain imaging

Treatment depends on the cause. When delirium or a medication is responsible, addressing it can help. For persistent distressing psychosis, a clinician may discuss options, including antipsychotic medicines. The drug labels for antipsychotic medicines carry a boxed warning, the most serious type of label warning, about increased risk of death when used in older adults with dementia-related psychosis, and they are not approved for that use. In Parkinson disease and dementia with Lewy bodies, some antipsychotics can worsen movement symptoms or cause severe reactions, so the prescriber needs to choose with particular care. That makes a careful discussion with the prescriber about benefits and risks important. Non-drug approaches are usually tried first, though a prescriber may consider a medicine when symptoms are severe or unsafe. Do not stop an antipsychotic that was already prescribed without talking to the prescriber.

How to respond at home

• Stay calm and speak in a quiet, even voice. Arguing about whether the hallucination or suspicion is real often increases distress.
• Acknowledge the feeling ("That sounds scary") and offer reassurance and safety.
• Reduce triggers: turn on good lighting, cover or remove mirrors if they are upsetting, and lower background noise.
• Keep routines steady, encourage regular sleep and fluids, and make sure glasses and hearing aids are in use.
• Check the environment for safety, including securing firearms, medications and car keys, and watch for wandering.
• Write down when episodes happen, what was said, and any recent changes, so the clinician can see the pattern.

Living with these symptoms is hard on caregivers. If you are worn down, our article on caregiver stress and its warning signs may help, and MedlinePlus lists support resources for Alzheimer's caregivers.

When thoughts of self-harm or violence are involved

Voices that urge someone to hurt themselves or others, threats or violence driven by paranoia, or any talk of suicide need urgent attention. Call 911 if the person is in immediate danger, has a plan or means to hurt themselves, is acting on voices telling them to harm someone, or is threatening or being violent toward others. In the US, call or text 988, the Suicide and Crisis Lifeline, at any time if the person is talking about suicide or self-harm and is not in immediate danger.

When to Seek Medical Care