Your aging mother thinks her trusted caretaker is stealing money from her wallet. Your spouse suddenly believes he hears the voice of his grandson (who lives in another state) warning him that he’s in imminent danger and telling him that he must leave the house immediately.

It can be frightening when a loved one experiences suspicious thoughts that have no rational basis—that is, paranoia. It’s a common phenomenon, but it is not a normal sign of healthy aging. And contrary to what many people believe, it’s not always dementia.


Paranoia involves intense or fearful feelings and thoughts related to persecution, threat or conspiracy. It’s often, but not always, accompanied by delusions—believing something to be true that is false.

Acting paranoid is a sign that something is off-kilter with the brain. While we don’t have reliable statistics for the causes of paranoia per se, my research has shown that we do have such data for the broader category of psychosis, a disconnect from reality, which is a reasonable stand-in because it often brings on paranoia.

At first glance, you might think psychosis is caused by schizophrenia. But that is the cause only 1% of the time. About 40% of the time, it’s due to dementia, whether caused by Alzheimer’s disease, Lewy body dementia or vascular disease.

What about the other 60%? There are many surprising causes—often eminently treatable. Here are the main ones, described below in order of how quickly they can be ­addressed…


About 10% of the time, psychosis is caused by a physical illness, nutritional deficiency or other health condition unrelated to dementia, such as…

• An imbalance of electrolytes—crucial nutrients that help regulate heart rhythm and muscle function—including sodium, potassium, calcium and magnesium. It can be caused by chronic conditions such as kidney disease but also by a bout of flu that leads to vomiting and

• Low levels of vitamins B-12 or folate—both conditions are common in the elderly.

• Infections, including pneumonia and urinary tract infections, which can be serious in the elderly. Serious infections can cause delirium, a state of worse-than-usual mental function that can bring on paranoia.

• A parathyroid tumor. The parathyroid glands, located on the thyroid gland in the neck, can develop noncancerous tumors. These can stimulate the release of excess calcium into the bloodstream, which affects behavior and can lead to paranoia. It’s curable with surgery.

These health problems can easily overwhelm an older adult. Once the underlying illness or deficiency is treated, however, the paranoia usually improves in a few days or, at most, weeks.

Important: The elderly experience thirst less intensely than younger people, often leading to dehydration. In individuals who already have mild memory problems, this can trigger a mild form of delirium, which often includes paranoia. Fortunately, reversal can be quick—give the person a glass of water or juice, and he/she will show signs of improvement in about 15 minutes.


Certain drugs, as well as alcohol, can cause paranoia, especially in the elderly. These are responsible for about 10% of psychosis/paranoia cases. Medications that are of particular concern…

• Benzodiazepines. Drugs including lorazepam (Ativan), diazepam (Valium) and alprazolam (Xanax) are often prescribed to help people sleep or manage anxiety but can lead to paranoia. Note: Stopping these drugs suddenly can be dangerous. Work with your doctor to discontinue them slowly.

• Anticholinergics. These drugs block the neurotransmitter acetylcholine—opposite to the mechanism of some Alzheimer’s drugs, which make acetylcholine more available to the brain.

Chronic use—daily for two years or more—is linked with an elevated chance of developing dementia, and it’s common for paranoia to be among the first symptoms that emerge. They are found in over-the-counter sleeping aids…drugs for overactive bladder, including oxybutynin (Ditropan) and tolterodine (Detrol)…and sedating allergy drugs such as diphenhydramine (Benadryl).


Delirium is responsible for approximately 10% of psychosis/paranoia cases. A common trigger is a hospital stay, especially one that includes surgery.

Rather than a single cause, delirium is often brought on by the rapid-fire combination of many destabilizing factors in a hospital stay—including overmedication (especially with painkillers, sedatives and sleeping pills), infection, isolation, dehydration, poor nutrition and sleep disturbance. Inadequately treated pain or constipation can also contribute to delirium.

Stunningly, experts estimate that about one-third of hospital delirium cases can be prevented. If your family member is slated for surgery, consult with a geriatric specialist at the hospital.

Very important: Ask if the hospital has an Acute Care for the Elderly (ACE) Unit, where specific measures are taken to keep geriatric patients mobile, well-rested, hydrated, out of pain and in regular contact with others.

Also helpful: Visit often and bring reminders of home such as family photos to ease feelings of isolation and disorientation.


Depression and bipolar disorder can bring on paranoid delusions, including the feeling of being punished. These conditions may be responsible for more than 30% of psychosis/paranoia in the elderly. Fortunately, effective treatment of the underlying disorders can reduce or eliminate the paranoia.


If your loved one shows signs of paranoia, it’s a safety issue, a health issue and a family crisis.

Do not attempt to reason with the person or explain why his/her paranoid thoughts are wrong. Instead, try to help the person feel heard and validated, then redirect if possible. If the person looks sick or unwell, is out of control or seems to be posing a serious risk of harming himself or someone else, consider the emergency room or even 911.

Next, insist on a thorough evaluation. Be persistent, because many doctors will just conclude that the person has dementia and leave it at that. This is especially important if paranoia symptoms come up suddenly—call the doctor for an urgent care appointment that includes evaluation for a new illness or medication side effect.

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