Impact of mild behavioral impairment on longitudinal changes in cognitive performance

Abstract

AbstractBackgroundRecent research has developed a better appreciation for non‐cognitive factors, such as neuropsychiatric symptoms (NPS), as early indicators for dementia. This has led to the development of criteria for mild behavioral impairment (MBI), or the late‐life onset of NPS. MBI has been associated with a unique cognitive phenotype, but research on longitudinal changes is limited. The goal of this study is to examine if MBI influences changes in cognitive abilities among older adults who are cognitively healthy (CH) or have mild cognitive impairment (MCI).MethodSecondary data analysis of participants (n=17,291) from the National Alzheimer’s Coordinating Center who were CH (n=11,771) or diagnosed with MCI (n=5,520). Almost 25% of the sample met the operationalized diagnostic criteria for MBI (n=4,274). Cognitive performance was evaluated using tasks of attention, episodic memory, executive function, language, visuospatial ability, and processing speed.ResultsCross‐sectionally, persons with MBI performed worse on tasks of attention, episodic memory, executive function, language, visuospatial ability, and processing speed compared to people without MBI. There were no significant interactions present between MBI and MCI on any of the tasks. Longitudinally up to 14 years, persons with MBI saw a greater decline on tasks of attention, executive function, language, episodic memory, and processing speed compared to individuals without MBI. Further, older adults with MBI performed significantly worse across time on tasks of executive function, language, and processing speed when compared to CH older adults without MBI. Persons with MBI and MCI performed significantly worse across time on tasks of executive function, language, processing speed, and visuospatial ability when compared to those with only MCI.ConclusionOlder adults with MBI performed worse on all cognitive domains, compared to those without MBI. Additionally, CH older adults with MBI saw a greater decline across time in the domains of executive function, language, and processing speed. In the MCI group, MBI was associated with a greater decline in all of these domains in addition to visuospatial ability. The results provide support for unique cognitive phenotypes for MBI in CH older adults and MCI, that may be indicative of preclinical and prodromal symptoms of dementia.