TORONTO ― Mild behavioral impairment (MBI), not memory woes, may be the first sign of mild cognitive impairment (MCI) or dementia, researchers from Canada propose.
MBI is defined as a syndrome of neuropsychiatric symptoms (NPS) that start later in life and are sustained for at least 6 months.
"Not a blip in behavior or reacting to a loss, but a real, meaningful change in behavior," lead researcher Zahinoor Ismail, MD, from the University of Calgary, explained in an interview with Medscape Medical News.
"Evidence shows that older adults with normal cognition and neuropsychiatric symptoms are more likely to become cognitively impaired and develop MCI than are people without neuropsychiatric symptoms," he noted.
Dr Ismail presented his research here at the Alzheimer's Association International Conference (AAIC) 2016.
By definition, MBI is a predementia syndrome occurring in older adults who are functionally independent and who are younger than typical dementia patients. MBI is thought to be the transitional state between normal aging and developing dementia, Dr Ismail said.
The symptoms of MBI, which are included in a proposed MBI checklist (MBI-C), focus on five domain, namely, changes in apathy/drive/motivation; mood/affect/anxiety; impulse control/agitation/reward; social appropriateness; and thoughts/perception.
Questions on the MBI-C were designed specifically to address a younger predementia population. The emphasis is on the fact that the emergence of NPS represents a significant change from prior behavior and is present for at least 6 months.
The MBI-C was developed by an expert group participating in the NPS Professional Interest Area (PIA) under the auspices of the Alzheimer's Association International Society to Advance Alzheimer's Research and Treatment (ISTAART).
"We propose that the utility of the MBI‐C ― once it is refined and vetted by the Alzheimer's community ― is significant not only clinically but also in research. In addition, we may be able to create or derive a version that can be provided to family members of older adults to determine the nature and extent of neuropsychiatric symptoms and to measure changes over time," Dr Ismail said in a conference statement.
"From a research perspective, the scale may prove to be usable in biomarker and neuroimaging studies in predementia clinical states, in epidemiological studies of community samples, and in clinical sample observational studies to help assess the impact of NPS in older adults," he added. Validation studies of the MBI-C are underway.
"This proposed new checklist describes and helps identify a new clinical stage in the disease and has the potential to represent a paradigm shift in formal neurodegeneration testing ― away from a sole focus on the memory to also encompass behavior.
"By looking beyond memory-related issues to closely evaluate the behavioral issues included in the checklist, physicians could reach a more efficient and accurate diagnosis sooner," Maria C. Carrillo, PhD, chief science officer of the Alzheimer's Association, said in a statement.
"Alzheimer's disease and dementia may not just be a memory disorder, and we need to stop thinking about Alzheimer's disease as just a memory problem," Dr Carrillo told Medscape Medical News.
"There are behavioral deficits that are associated with it. It may start with depression or anxiety or disorientation or aggression. I think [clinicians] have to think of behavioral symptoms as a potential [harbinger] of dementia and not just dismiss them or just prescribe a medication," she added.
Penny Dacks, PhD, director, Aging and Alzheimer's Prevention at the Alzheimer's Drug Discovery Foundation, said this research is important.
"We know that neuropsychiatric symptoms of Alzheimer's are a major unmet clinical need, and there are no adequate available treatments. The tool here is a step in the right direction to recognize the other symptoms of Alzheimer's that matter tremendously to the patients and the families. It's also part of a growing movement to recognize that Alzheimer's might not just be one single disease but rather a syndrome with a range of potential symptoms, and those symptoms can vary across patients," she told Medscape Medical News.
"We do need to be careful in that these psychiatric aspects are not necessarily going to be unique to Alzheimer's disease," Dr Dacks cautioned.
"But the beauty of what they've provided is that it's a tool to think about and better start tracking these symptoms. Can we use it to better define subsets of Alzheimer's patients who might have slightly different manifestations of the disease and might respond better to different treatments?"
The MBI-C, Dr Dacks said, "isn't going to be a stand-alone test that says you have Alzheimer's disease, but it could be an important piece of the puzzle to better diagnose the disease early and a fantastic research tool, and I hope in the long term it might help us understand whether treating some of these neuropsychiatric symptoms can in fact both help the patient and in the long term, could it even help with the process of the disease? We don't know."
This research was funded by the Hotchkiss Brain Institute through the Alzheimer Society Calgary. Dr Ismail, Dr Carrillo, and Dr Dacks have disclosed no relevant financial relationships.
Alzheimer's Association International Conference (AAIC) 2016. Abstract O1-13-03. Presented July 24, 2016.