Dementia with Lewy bodies is the second most widespread neurodegenerative cause of dementia. It shares characteristics with both Alzheimer's and Parkinson's disease. Getting the accurate diagnosis is particularly important because some medications used to treat the mental health symptoms of Alzheimer's disease can be potentially hazardous for people with dementia with Lewy bodies.
The study found that even prior to diagnosis, people with dementia with Lewy bodies showed passive personality changes, such as diminished emotional reaction, indifference to hobbies, repetitive behaviours, and growing apathy, or lack of interest, more often than those with Alzheimer's.
The study involved 290 people who were part of a larger study and were tested every year for an average of about five years. By the end of the study, 128 of the participants had established cases of dementia with Lewy bodies, 128 had Alzheimer's and 34 had no form of dementia.
Researchers followed the participants through death, including autopsy results. During yearly interviews, participants or their family members were asked about changes in personality, interests and drives.
People with dementia with Lewy bodies were two times more prone to have passive personality traits at the time of the first assessment than people with Alzheimer's disease. By the time of death, up to 75 percent of those with dementia with Lewy bodies had passive personality changes compared to 45 percent of those with Alzheimer's disease.
"Currently we mainly look for memory problems and other cognitive problems to detect dementia, but personality changes can often occur several years before the cognitive problems.
Identifying the earliest features of dementia may enable doctors to begin therapy as soon as possible. This will become increasingly important as newer, potentially disease-modifying medications are developed. It also gives the patient and family members more time to plan for the progressive decline," said study author James E. Galvin, MD, MPH, of Washington University School of Medicine in St. Louis, MO, and member of the American Academy of Neurology.
Galvin also added that more thorough personality tests are not often used in most office settings because of time and lack of training.
"Our results show incorporating a brief, simple inventory of personality traits may help improve the detection of dementia with Lewy bodies," said Galvin.
The study is published in the May 29, 2007, issue of Neurology, the scientific journal of the American Academy of Neurology.