Moments of Sheer Terror: When
People with Dementia Act on
Delusional Beliefs
Colleen Millikin, Ph.D., C.Psych.
Department of Clinical Health Psychology
Faculty of Medicine
University of Manitoba
What are delusions?
What causes delusions in dementia?
Risk factors
Common types of delusions in dementia
Nonpharmacological approaches
Examples in community and long-term care
Pharmacological approaches
Role of environment
• Delusional beliefs (delusions) are:
– false beliefs that are resistant to logic
– associated with strong emotions (fear, anger) that
prompt the person to act on the beliefs
• Delusions occur in:
– psychotic illnesses (schizophrenia, bipolar
– delirium (e.g., metabolic imbalance)
– dementia
Causes of Delusions
• Mechanisms involved in delusions are not
well understood
• Theories involve:
– attempt by people with dementia to understand
their environment
– related to mood changes
– caused by factors unrelated to dementia process
– directly caused by underlying brain damage
Causes of Delusions
• More theories:
– dysfunction in specific brain areas (greater
asymmetry in brain atrophy)
– right hemisphere dysfunction
– neurotransmitter disturbances
– imbalance between intact attention and impaired
memory/semantic processing ability
Delusions and Dementia
• Not all people with dementia develop
delusions but many do - difficult to predict
who will/won’t develop delusions
• Some people have delusions (delusional
disorder) but not dementia
– these delusions tend to be more complex,
persecutory or grandiose
Delusions and Dementia
• 30-40% percent of people with Alzheimer’s
disease develop delusions at some point in the
disease process (reported incidence rates in
studies range from 10% to 73%)
• Delusions common in dementia of Parkinson’s
disease, vascular dementia, and Lewy Body
Disease (70% of people with LBD have
complex visual hallucinations and/or paranoid
Delusions and Dementia
• Risk factors for development of delusions (not
consistently found in all studies):
older age
female gender
less education
African-American race
Delusions and Dementia
• Risk factors for development of delusions
(more consistent evidence):
– more severe cognitive impairment (especially
frontal and temporal lobe dysfunction)
– more common during moderate stage (compared
to very mild or very severe dementia)
Delusions and Dementia
• Other risk factors:
– delirium (medications, infections (UTI,
pneumonia), low sodium, etc.)
– sensory impairment
– basal ganglia infarct (often sudden onset)
Delusions and Dementia
• Delusions in Alzheimer’s disease are
associated with:
– increased likelihood of depression in person with
– caregiver distress
– earlier institutionalization
– more rapid progression of dementia
– more aggressive behaviour
Common Delusions in Dementia
• Delusion of theft (belief that people are
stealing or hiding things, most common, 22%)
– often related to memory impairment
• Phantom boarder (belief that other people are
living in the home, 20%)
• Persecution and endangerment (belief that
others are “out to get me” or that food is being
poisoned, 17%)
Common Delusions in Dementia
• Delusion of infidelity (belief that spouse is
unfaithful, 5%)
– may be related to memory impairment
• One’s house is not one’s home (5%)
– likely related to agnosia (inability to recognize
• Delusions related to television (belief that
events on TV are happening in real life, 5%)
Common Delusions in Dementia
• Picture sign (believing that their mirror image
is someone else, 5%)
• Delusions of infestation (believe that they or
their home are infested by small organisms,
spiders, ants, lice, etc., 5%)
• Abandonment (belief that caregiver will
abandon them or put them in a nursing home,
Common Delusions in Dementia
• Delusional misidentification (belief that a
familiar person has been replaced by an
imposter, Capgras syndrome, 3%)
– likely related to agnosia (inability to recognize
• Delusions of love (belief that a prominent or
famous person is secretly in love with them,
De Clerambault’s syndrome, 1%)
Common Delusions in Dementia:
• Delusions of theft
– can lead to people hiding things, wearing several
layers of clothing
• Delusions of persecution
– can lead to people barricading themselves in their
• One’s house is not one’s home
– may leave home in search of “home”
Common Delusions in Dementia:
• Delusions of infidelity
– can lead to aggression toward spouse
• Delusions of poisoning
– can lead to refusal of food and/or medication
Transient vs. Enduring Delusions
• Delusions of theft, infidelity, etc. may be
enduring (affecting behaviour almost every
• Many people also have transient delusions
that may occur only once, regularly at a
particular time of day, or for a period of
• These types of delusions not described in
literature on delusions in dementia
Causes of Transient Delusions
• In persons with dementia, delusional
behaviour may be reliving of past experiences
• Brain can’t form new memories, so it recycles
old ones
• Often triggered by events in the environment
(e.g., time of day, activities, food)
• Particularly challenging if person has a history
of trauma (child abuse, war experiences, etc.)
Nonpharmacological Approaches
• If delusion is not distressing to person with
dementia, may not need intervention
• If person is low risk to self or others,
nonpharmacological approaches should be
tried first
Nonpharmacological Approaches
• General approaches (Rabins, Lyketsos, & Steele, 2006;
Harvey, 1996):
remain calm
distraction (e.g., discussion of other topics)
frequent scheduled activities
one to one attention
remove clutter from the environment (theft)
periodic separation from person who is the target
of suspicions (e.g., spouse)
Nonpharmacological Approaches
• General approaches:
– improve clarity of communication with person
(reduce chance of misinterpretation)
– offer reassurance when person is confused
– assess possibility of depression (in some cases,
delusions can improve with antidepressant
– conversation about the feelings behind the false
Nonpharmacological Approaches
• Paranoid delusions:
– be honest and keep any promises you make
– explain any procedures you intend to do before
doing them so person knows what to expect
– try to keep daily routine as consistent as possible
– avoid talking, laughing, or whispering where
person might see you but not hear what is said
Nonpharmacological Approaches
• Paranoid delusions:
– do not take person’s suspicions personally
– do not agree with person that you did something
you did not do
– DO NOT ARGUE with person (state once that
you did not do what you are accused of and do not
talk about matter any further for at least an hour)
Nonpharmacological Approaches
• Paranoid delusions:
– if food is an issue, serve food and drink directly in
front of person - let person choose food from a
tray of items that are all the same
– if person is particularly suspicious of one
caregiver, avoid having that person provide care if
– have one caregiver listen to person for a brief time
each day and validate person’s feelings
Nonpharmacological Approaches
• Paranoid delusions:
– “I know you believe this is true, but it is not real.
Sometimes people’s minds play tricks on them. It
must be very frightening to believe that. No one is
going to hurt you here.”
– provide reassurance
– recognize that you cannot talk person out of belief
– belief is real to the person
Nonpharmacological Approaches
• “This is not my house”:
– “I guess it doesn’t look familiar, but this is your
house.” (Then change the subject.)
– help person focus on familiar detail that does not
rely on visual identification
– respond to feeling (“I know you want to go
• “Someone stole my watch.”
– “I’ll help you look for it.”
– have duplicates of important items
Nonpharmacological Approaches
• “You are not my husband”:
– reassure person (“I am your husband.”) but avoid
– try distracting person with familiar activity
• “My mother is coming for me.”
– respond to feeling of loss person may be
expressing (“Tell me about your mother.”)
– do not contradict person or play along with
delusional belief
Examples in Community
• “You have to incubate the specimens.” (3:00
AM, 69 year-old man with frontal-temporal
• “I have to get to the bank.” (morning, January
1, 70 year-old man with vascular dementia)
• “I have to fix the toilet.” (afternoon to evening
to night, 82 year-old man with vascular
dementia and low blood sodium)
Examples in LTC
• “That’s not the way I designed it.” (65 yearold man with normal pressure hydrocephalus)
• “I can’t come with you, my parents will be
here soon to take me home.” (92 year-old
woman with Alzheimer’s disease)
• “The kitchen is over this way.” (82 year-old
woman with visual impairment and probable
Lewy Body Disease)
Pharmacological Approaches
• May be necessary in delusional disorder,
especially if past history of psychosis that
responded to medication
• Antipsychotic medication usually does not
take delusions away, but person cares about
them less so is less likely to act on them
• Risks associated with neuroleptics
The Role of the Environment
• Identify triggers (time of day, etc.) then
change routine to decrease triggers
• Reduce impact of sensory impairment to
extent possible (lighting, hearing aids, noise)
• May help to reduce clutter (less chance of
losing things)
• If behaviour is relatively benign, change
approach of staff toward behaviour (treat it as
“normal”) - example of “security guard”
Questions and
Bassiony, M.M., & Lyketsos, C.G. (2003). Delusions and hallucinations in
Alzheimer’s disease: Review of the brain decade. Psychosomatics, 44,
Fischer, C., Bozanovic-Sosic, R., & Norris, M. (2004). Review of
delusions in dementia. American journal of Alzheimer’s disease and
other dementias, 19(1), 19-23.
Fischer, C., Ladowsky-Brooks, R., Millikin, C., Norris, M., Hansen, K., &
Rourke, S.B. (2006). Neuropsychological functioning and delusions in
dementia: A pilot study. Aging & Mental Health, 10(1), 27-32.
GrahamNorth, B., & Lazar, D. (1999, unpublished manuscript). Care-full
elder care: A manual for staff in personal care homes.
Harvey, R.J. (1996). Review: Delusions in dementia. Age and Ageing, 25,
Mace, N.L., & Rabins, P.V. (1999). The 36-hour day, third edition.
Baltimore, MD: Johns Hopkins University Press.
Rabins, P.V., Lyketsos, C.G., & Steele, C.D. (2006). Practical dementia
care, second edition. New York, NY: Oxford University Press.

Moments of Sheer Terror: When People with Dementia Act on