* Episode 8: Delusions in Dementia Translation from Japanese

English Translation from Japanese — “Delusions in Dementia”

Episode 8: Delusions in Dementia

By Yukimichi Imai, M.D.

Director, Wakō Hospital, Suikai Medical Corporation

Former Board Member, Japanese Society for Dementia Care

“Delusion of theft”—believing that one’s belongings have been stolen—is one of the most well-known symptoms seen in dementia. For example, when a person with dementia forgets where they put their wallet, they may think, “Someone might have stolen it,” and that suspicion develops into the delusion, “Someone definitely stole it.” Then they accuse a close family member of being a “thief,” which becomes a very distressing situation for the family.

Other common delusions include persecutory delusions, such as “People are bullying me,” “People hate me,” or “Someone is trying to kill me,” and also jealous delusions, such as “My husband is having an affair.”

Some individuals even treat their own spouse as if they were a stranger, or become convinced that a deceased person or someone who does not exist is “right there.”

Why do such delusions appear in people with dementia?

What Are Delusions?

A delusion is a firmly held false belief about something that could not be true in reality. Even if people around the individual deny it and try to correct the misunderstanding, the belief cannot be changed.

Thus, when a person with dementia develops a “delusion of theft,” no matter how many times you deny it or explain that such a thing is impossible, they will never abandon that belief.

Studies show that delusions are relatively common in dementia.

A survey conducted in Tokyo found that about 15% of people with dementia experience delusions. Reports indicate that delusions appear in:

• 15–56% of those with Alzheimer’s dementia
• 27–60% of those with vascular dementia

Most delusions have a persecutory nature. In particular, the “delusion of theft,” where the person insists that their wallet or bankbook has been stolen, is extremely common—over 80%.

Unlike schizophrenia, where delusional content is fixed and consistent, delusions in dementia have the following characteristics:

• The content changes frequently
• The delusions are often related to past experiences
• The target of the delusion is usually a very close family member

Why Are Close Family Members Targeted?

Let us imagine the thinking process of a person with a delusion of theft.

When they notice their important wallet is missing, they panic: “This is terrible!”

At that moment, they do not think, “I must have put it somewhere,” nor do they try to look for it. Instead, they jump to:

“Someone must have taken it.”

“Someone definitely stole it.”

Then, if the person who usually cares for them happens to be nearby, the individual becomes convinced, “It must have been that person who stole it.”

They do not think, “If I accuse them, our relationship will get worse.” Instead, they react impulsively, saying, “You stole my wallet!”

Naturally, the accused family member strongly denies it and becomes upset.

Seeing this reaction, the person with dementia becomes even more convinced:

“He is getting angry because he stole it!”

Once this happens, no amount of denial or explanation will change the belief.

How Small Behaviors Trigger Other Delusions

Other persecutory delusions also tend to be triggered by small actions or gestures from people around the individual.

For example:

During meals, the family may talk about something the person cannot understand

The person may feel ignored or excluded

This leads to thoughts such as:

“They are leaving me out.”

“It would be better if I weren’t here.”

If a spouse shows even a small sign of indifference, this may develop into the jealous delusion,

“He is having an affair.”

At first, when family members say,

“That’s not true,”

“You’re misunderstanding,”

the person may partially listen.

However, over time, the delusion becomes completely fixed and impossible to correct.

Delusional Misidentification Syndromes

A group of delusions related to misidentification is often seen in dementia. These include:

• Capgras syndrome
• Phantom boarder syndrome
• Mirror sign
• TV sign

Capgras Syndrome

This is the conviction that a close family member has been replaced by someone else who looks identical.

In 1923, Capgras reported the case of a 53-year-old woman who believed that there were several impostor versions of her daughter.

Originally thought to be limited to conditions such as schizophrenia or affective disorders, it is now known to occur in dementia and other brain disorders.

Phantom Boarder Syndrome (the “invisible roommate”)

The belief that an unknown person is living in one's home.

People say things like:

• “Someone is in my room.”
• “There are many children here.”

In this case, it can be difficult to determine whether it is a hallucination or a delusional misidentification.

Even if the person has not seen anyone, they are fully convinced:

“There is someone here.”

Mirror Sign

The person cannot recognize their reflection as themselves and mistakes it for another person.

They may talk to the reflection or try to give it food.

This occurs particularly in advanced dementia.

TV Sign

The person mistakes scenes on television for reality, talks to the characters, or becomes angry at what they see.

Impact on Families

When a person strongly asserts something that is clearly untrue, it is extremely shocking for family members—especially those who care for the person every day.

While memory lapses may be dismissed as “old age,” delusions are more difficult to handle and often prompt families to seek medical help.

At the memory clinic, the first step is to determine whether the delusions arise from dementia.

Delusions may also appear in:

• mood disorders
• schizophrenia
• various brain diseases 
• medical conditions

These must be differentiated.

Treatment Considerations

Antipsychotic medications can sometimes be effective.

However, in older adults, these drugs are started at one-half to one-third of the usual adult dose due to side effects.

If ineffective, the dose may be gradually increased with caution—but this remains symptomatic treatment, not a cure.

To eliminate the delusion, the cause must be identified.

Sometimes brain diseases or physical illnesses may trigger delusions, in which case treating the underlying illness takes priority.

More commonly, delusions arise from environmental factors surrounding the person with dementia.

Examples include:

• rearranging furniture
• ignoring the person’s attempts to speak
• sudden changes in living environment such as short-stay facilities

These seemingly small changes can trigger delusions.

Thus, careful attention to the person's environment, behavior, and emotional needs is crucial.

How to Respond at Home

Because delusions cannot be corrected, denying or trying to persuade the person tends to worsen agitation.

The following approaches may be helpful:

1) Listen to the person first

Even if the delusion is directed toward the caregiver and the accusation feels unfair, try to suppress the urge to deny or correct.

Respond with empathy.

2) If accused (“You stole my wallet!”), return the statement as a question

For example:

“Your wallet is missing? That must be upsetting.”

“Do you think someone took it?”

Do not argue or attack; simply reflect their words back as questions.

3) If the person becomes more agitated, gently step away

Say something like:

“I need to go to the bathroom. I’ll be right back.”

A brief separation may help calm the person.

However, avoid suddenly running away, as this can increase agitation.

4) If the delusions persist, consult a psychiatrist as early as possible

(March 2, 2013)

Advice from Dr. Yukky (Imai Yukimichi)