Aggression Looks Different in Alzheimer’s Vs. Frontotemporal Dementia

For caregivers, watching a loved one struggle with memory loss can be devastating. The aggression that sometimes accompanies memory loss can be even harder to grapple with—literally and figuratively. Sometimes people with Alzheimer’s disease or other dementias lash out unexpectedly. It might be traced to a physical cause, like an uncomfortable infection that hasn’t been treated. It might be due to an environmental stress, like loud noises or a large crowd.

“If you notice socially deviant or criminal behavior
in a person who has previously acted normally,
you should be attentive and help the person get
examined by a physician, as it could
be the first sign of dementia.”

Sometimes, though, the reason isn’t so easy to pinpoint. A new study from Lund University in Sweden found that one third of patients with frontotemporal dementia or Alzheimer’s disease were physically aggressive toward healthcare staff, relatives, strangers and animals.

Aggression manifest differently in different forms of dementia

The study found that there are differences in aggression depending on the type of dementia.

For people with frontotemporal dementia, physical aggression started early in their disease. The frontal parts of the brain control things like empathy, impulse, personality and judgment. Alzheimer’s, on the other hand, is located further back in the brain, in an area associated with memory and orientation in space and time.

People living with Alzheimer’s were more likely to be physically aggressive, though that behavior was less frequent, less violent, and less likely to be directed at strangers than behavior observed in those with frontotemporal dementia.

Another clear distinction arose around at whom the anger or aggression was directed: The study found that twenty-one percent of physically aggressive patients with frontotemporal dementia directed their aggression at strangers, compared to two percent of Alzheimer’s patients.

Are symptoms worse in early dementia?

Clinicians have suspected that people with early-onset Alzheimer’s, which becomes symptomatic in people aged 65 or younger, tend to decline more rapidly than those with the more common late-onset Alzheimer’s. Studies have shown that the brains of those with early-onset Alzheimer’s tend to have greater degeneration, compared to late-onset Alzheimer’s patients. But, whether early-onset Alzheimer’s comes with greater severity of behavioral symptoms (also known as neuropsychiatric symptoms) hasn’t been clearly shown in research.

One study published in the European Journal of Neurology indicated that these types of neuropsychiatric symptoms — including aggression — were more severe in patients with early-onset Alzheimer’s than those with late-onset Alzheimer’s.

“The differences in clinical symptoms may reflect differences in how the disease — the tau or amyloid proteins — are spreading within the brain,” Dr. Neus Falgàs, a postdoctoral researcher at the University of California San Francisco, told Being Patient. “It’s a way to know better how the disease progresses over time within” the different forms of Alzheimer’s.

What should I do if I notice extreme personality changes in my loved one?

Physical aggression or extreme changes in behavior can be an early sign of dementia.

“If you notice socially deviant or criminal behavior in a person who has previously acted normally, you should be attentive and help the person get examined by a physician, as it could be the first sign of dementia,” said lead study author of the Lund University Madeleine Liljegren.

UPDATED MARCH 31, 2023: This article from September 2017 was updated to provide additional information for our readers.