Behavioral and psychological symptoms are difficult for dementia patients and their caregivers, but despite research efforts, there are still gaps in knowledge about what causes or precipitates these symptoms, according to researchers.

In a review, the researchers analyzed previously published studies on the causes and precipitants of behavioral and psychological symptoms of dementia (BPSD). They found that while there have been many studies on patient determinants — individual characteristics within the person suffering from dementia — research was lacking in other areas.

“We found that there haven’t been many studies done on how a patient’s caregiver or environment can trigger or affect these symptoms,” said Ann Kolanowski, professor of nursing at Penn State. “In order to best treat people living with dementia, we need to learn more about all the possible causes of behavioral and psychological symptoms, and further research into these specific areas is needed.”

Dementia is almost always accompanied by BPSD. These symptoms, which include such behaviors as aggression and agitation, contribute to a poorer quality of life and a more rapid decline in cognitive and physical abilities.

Kolanowski said that not only are these symptoms difficult for the person, but that people who exhibit them also are placed into care facilities more often than those who do not.

“Families have a hard time responding well to aggression, or psychosis, or people wandering out of their homes at night. It's exhausting to them,” she said. “We need to learn more about the factors precipitating these symptoms, so we can design approaches and interventions that will reduce them. Not only for the benefit of the person suffering from dementia, but also the caregivers.”

The team gathered research on five of the most common BPSD in people with dementia: aggression, agitation, apathy, depression and psychosis. After compiling the available research on what causes or influences these symptoms, the researchers narrowed their focus to 56 high-quality, low-bias research papers. They then combined the study results into one report, published in the journal Nursing Outlook.

The researchers found evidence that certain factors affected multiple BPSD, including neurodegeneration, the type of dementia and the severity of the cognitive impairments.

But the team also identified areas that are lacking in research, including how BPSD affect the progression of dementia and how environment and caregiver behavior can influence BPSD. They found that while there is some evidence for such factors as caregiver burden and communication skills affecting BPSD, there were not enough studies conducted, according to the researchers.

“Learning about how factors within the person affect BPSD is important, but less is known about how the environment or caregiver might influence these symptoms,” Kolanowski said. “If we know more about how external factors influence BPSD, that could powerfully affect how we design treatments and interventions.”

Kolanowski said that she hopes the report will help other nursing researchers both better understand what already has been discovered and to inspire them to branch out into other areas where research is needed.