Mild behavioral impairment as a predictor of cognitive functioning in older adults

Abstract

Objective: To assess the influence of mild behavioral impairment (MBI) on the cognitive performance of older adults who are cognitively healthy or have mild cognitive impairment (MCI). Methods: Secondary data analysis of a sample (n = 497) of older adults from the Florida Alzheimer’s Disease Research Center who were either cognitively healthy (n = 285) or diagnosed with MCI (n = 212). Over half of the sample (n = 255) met the operationalized diagnostic criteria for MBI. Cognitive domains of executive function, attention, short-term memory, and episodic memory were assessed using a battery of neuropsychological tests. Results: Older adults with MBI performed worse on tasks of executive function, attention, and episodic memory compared to those without MBI. A significant interaction revealed that persons with MBI and MCI performed worse on tasks of episodic memory compared to individuals with only MCI, but no significant differences were found in performance in cognitively healthy older adults with or without MBI on this cognitive domain. As expected, cognitively healthy older adults performed better than individuals with MCI on every domain of cognition. Conclusions: The present study found evidence that independent of cognitive status, individuals with MBI performed worse on tests of executive function, attention, and episodic memory than individuals without MBI. Additionally, those with MCI and MBI perform significantly worse on episodic memory tasks than individuals with only MCI. These results provide support for a unique cognitive phenotype associated with MBI and highlight the necessity for assessing both cognitive and behavioral symptoms.

Mild Behavioral Impairment and Subjective Cognitive Decline Predict Cognitive and Functional Decline

“…Cognitive and behavioral pre-dementia risk axes. [10][11][12][13][14][15][16][17], as well as known dementia markers including amyloid-␤ [18], tau [19,20], neurofilament light [21], temporal lobe atrophy [22,23], frontal lobe atrophy [24], white matter atrophy [25], functional dysconnectivity [26,27], and AD genetic loci [28,29]. This body of evidence suggests that in some older adults, MBI may be a consequence of emerging dementia proteinopathies which manifest independently or in concert with cognitive symptoms.…”

Mild behavioral impairment: challenges facing a quickly developing evidence base

“…In a 2 (MCI: presence or absence) × 2 (MBI: presence or absence) Multivariate Analysis of Co-Variance, Rouse et al (2020) showed that, regardless of cognitive status, MBI was associated with poorer executive function, attention and episodic memory; and that co-morbid presentation of MBI and mild cognitive impairment resulted in significantly poorer performance on tasks of episodic memory when compared to a mild cognitive impairment only cohort. The authors conclude that the current findings not only corroborate the notion of MBI as an at-risk state for cognitive decline (e.g.…”

“…Having said that, the prevalence rates reported across all three studies (Mortby et al, 2018b, Rouse et al, 2020, Sheikh et al, 2018 need to be interpreted with caution, as they may in fact represent inflated prevalence rates. The reason for this is the discrepancy between the reference timeframes used by the assessment tools.…”

“…Some consideration needs also to be given to the prevalence rates of MBI reported in the current study, as the original study was not designed to investigate MBI, and thus did not include the novel MBI-Checklist. Similar to other population-based cohort and clinical studies which have used data collected prior to the development of the MBI-Checklist, Rouse et al (2020) assessed MBI using a previously published MBI operationalization matrix (e.g. Mortby et al, 2018b, Sheikh et al, 2018, Andrews et al, 2018.…”

“…Using this operationalized matrix and a 1-month reference range, Rouse et al (2020) reported MBI prevalence rates in 38.6% of cognitively healthy participants and 67.9% of participants with mild cognitive impairment. These prevalence rates lie between those reported by Mortby et al (2018b) in an Australian population-based sample taken from the Personality and Total Health (PATH) Through Life study (27.6% in cognitively normal and 48.9% in mild cognitive impairment) and by Sheikh et al (2018) in a Canadian clinical sample taken from the Prospective Study for Persons With Memory Symptoms (PROMPT) study (85.3% in mild cognitive impairment).…”