Karr et al., 2018. When does cognitive decline begin?

Karr, J. E., Graham, R. B., Hofer, S. M., & Muniz-Terrera, G. (2018). When does cognitive decline begin? A systematic review of change point studies on accelerated decline in cognitive and neurological outcomes preceding mild cognitive impairment, dementia, and death. Psychology and Aging, 33(2), 195-218.

Year: 
2018
Status: 
complete
Abstract: 

Older adults who ultimately develop dementia experience accelerated cognitive decline long before diagnosis. A similar acceleration in cognitive decline occurs in the years before death as well. To evaluate preclinical and terminal cognitive decline, past researchers have incorporated change points in their analyses of longitudinal data, identifying point estimates of how many years prior to diagnosis or death that decline begins to accelerate. The current systematic review aimed to summarize the published literature on preclinical and terminal change points in relation to mild cognitive impairment (MCI), dementia, and death, identifying the order in which cognitive and neurological outcomes decline and factors that modify the onset and rate of decline. A systematic search protocol yielded 35 studies, describing 16 longitudinal cohorts, modeling change points for cognitive and neurological outcomes preceding MCI, dementia, or death. Change points for cognitive abilities ranged from 3–7 years prior to MCI diagnosis, 1–11 years prior to dementia diagnosis, and 3–15 years before death. No sequence of decline was observed preceding MCI or death, but the following sequence was tentatively accepted for Alzheimer’s disease: verbal memory, visuospatial ability, executive functions and fluency, and last, verbal IQ. Some of the modifiers of the onset and rate of decline examined by previous researchers included gender, education, genetics, neuropathology, and personality. Change point analyses evidence accelerated decline preceding MCI, dementia, and death, but moderators of the onset and rate of decline remain ambiguous due to between-study modeling differences, and coordinated analyses may improve comparability across future studies. (PsycINFO Database Record (c) 2018 APA, all rights reserved)

 

Yoneda et al., 2018. Trajectories of Personality Traits Preceding Dementia Diagnosis

Yoneda, T., Rush, J., Berg, A. I., Johansson, B. & Piccinin, A. (2017). Trajectories of Personality Traits Preceding Dementia Diagnosis. The Journal of Gerontology Series B: Psychological Sciences and Social Sciences, 72(6), 922-931, DOI: 10.1093/geronb/gbw006

Year: 
2017
Status: 
complete
Presentation Citations: 

Yoneda, T. & Piccinin, A. A coordinated analysis examining personality change in older adults: Consistent results despite heterogeneity between datasets (November, 2018). Symposium Presentation to be presented at the Gerontological Society of America Conference, Boston, MA.

Yoneda, T., Rush, J., Knight, J., Graham, E. K., Mroczek, D., Berg, A. I., Johansson, B., Pedersen, N., Comijs, H., Katz, M., Lipton, R. & Piccinin, A. (2017). Investigation of Personality Using Different Time Matrices, Control Variables and Inclusion Groups. Poster Presentation at IAGG conference in San Francisco. 

Yoneda, T., Rush, J., Graham, E. K., Mroczek, D., Berg, A. I., Johansson, B., Pedersen, N., Comijs, H., Katz, M., Lipton, R. & Piccinin, A. (November, 2016). Trajectories of Personality Traits Preceding Dementia Diagnosis: A Coordinated Analysis. Symposium Presentation at the Gerontological Society of America Conference, New Orleans, LA.  

Yoneda, T. (2016). Trajectories of Personality Traits Preceding Dementia Diagnosis: A Coordinated Analysis. Unpublished Master’s Thesis, University of Victoria, Victoria, BC. 

Yoneda, T., Rush, J., Berg, A. I., Johansson, B., Comijs, H. & Piccinin, A. (November, 2015). Trajectories of Personality Traits Preceding Dementia Diagnosis: A Coordinated Analysis. Poster Presentation at the Gerontological Society of America Conference, Washington, D.C.
 

Yoneda, T., Piccinin, A. & Johansson, B. (April, 2015). Association between cognition and personality change in the oldest-old. Presentation at University of Victoria Social Dimensions of Health 2015 Conference, Victoria, BC.

Yoneda, T., Koval, A., Johansson, B. & Piccinin, A. (November, 2014). Personality change preceding diagnosis of dementia in the oldest-old. Poster Presentation at the Gerontological Society of America Conference, Washington, D.C.

Abstract: 

Introduction: Although personality change is typically considered a symptom of dementia, some studies suggest that personality change may be an early indication of dementia. This project examines this possibility by examining trajectories of personality traits preceding dementia diagnosis in several longitudinal studies of aging.

Methods: Three independent series of latent growth curve models were fitted to data from the Origins of Variance in the Oldest-Old (OCTO-Twin), Longitudinal Aging Study Amsterdam (LASA) and Einstein Aging Study (EAS) to estimate trajectories of personality traits in individuals with incident dementia diagnosis (Total N = 295), in individuals with incident Mild Cognitive Impairment (N = 135), and in individuals who did not receive a diagnosis during follow-up periods (Total N = 2109).

Results: Controlling for sex, age, education, depressive symptoms, and the interaction between age and education, growth curve analyses consistently revealed significant linear increases in neuroticism preceding dementia diagnosis in both datasets and in individuals with MCI. Analyses examining individuals without a diagnosis revealed non-significant change in neuroticism overtime.

Discussion: Replication in several datasets provides compelling evidence that increases in neuroticism may be early indication of dementia, which can facilitate development of screening assessments and aid in early care strategies.

Knight et al., 2018. Olfactory Identification and Episodic Memory in Older Adults

Knight, J. E., Bennett, D. A., & Piccinin, A. M. (2018). Variability and Coupling of Olfactory Identification and Episodic Memory in Older Adults. The Journals of Gerontology: Series B. DOI: 10.1093/geronb/gby058. 

Year: 
2018
Status: 
complete
Presentation Citations: 

Knight, J. E., & Piccinin, A. M. (2018, April). Poster. Foreshadowing Alzheimer’s: Variability and Coupling of Olfaction and Cognition. In D. Burgoyne & R. Gooding (Eds.), Research Now: Contemporary Writing in the Disciplines. Broadview Press.

Knight, J. E., & Piccinin, A. M. (2017, July). Foreshadowing Alzheimer’s: Variability and Coupling of Olfaction and Cognition. Poster presented at 21st IAGG World Congress of Gerontology and Geriatrics (IAGG), San Francisco, USA.

Knight, J. E., & Piccinin, A. M. (2016, November). Olfaction as a Predictor of Alzheimer’s Disease Pathology in Old Age: A Growth Curve Analysis. Poster presented at Gerontological Society of America (GSA) Scientific Meeting, New Orleans, USA

Knight, J. E., & Piccinin, A. M. (2016, July). Olfaction as a Risk Factor for Dementia, Mortality and Stroke. Poster presented at Alzheimer’s International Conference (AAIC), Toronto, CA.

Abstract: 

Objectives: To determine whether assessment-to-assessment fluctuations in episodic memory (EM) reflect fluctuations in olfaction over time.

Methods: Within-person coupled variation in EM and the Brief Smell Identification Test (BSIT) was examined in 565 participants aged 58–106 with autopsy data from the Rush Memory and Aging Project. A growth model for up to 15 years of EM data, with BSIT as time-varying covariate, was estimated accounting for main effects of sex, education, ε4 allele, and Alzheimer’s disease (AD) pathology, BSIT and time-varying BSIT, as well as the interaction between AD pathology and time-varying BSIT.

Results: Individuals with higher BSIT scores (b = .01, standard error [SE] = .004, p = .009) had slower declines in EM. High AD pathology (b = −.06, SE = .02, p = .001) was associated with more rapid declines in EM. The association between time-specific fluctuations in EM and BSIT differed by level of AD pathology (b = .08, SE = .034, p = .028), with a higher EM–BSIT association at higher levels of pathology. Discussion: BSIT and EM fluctuate together over measurement occasions, particularly for individuals with AD pathology. Repeated intraindividual measurements provide information that could lead to early detection and inexpensive monitoring of accumulating AD pathology.

PIccinin et al., 2011. Terminal Decline From Within- and Between-Person Perspectives, Accounting for Incident Dementia

Piccinin, A.M., Muniz, G., Matthews, F. & Johansson, B. (2011). Terminal decline from within and between person perspectives, accounting for incident dementia. Journal of Gerontology: Psychological Sciences, 66(4), 391-401.

Year: 
2011
Status: 
complete
Presentation Citations: 

Muniz, G., Piccinin, A.M., Johansson, B. Matthews, F. & Hofer, S. M. (November, 2011). Do all individuals experience a change in age-related cognitive decline? In A.M. Piccinin & G. Muniz (Chairs), Advances in Understanding Cognitive Aging: Longitudinal Research on Change, Variation, and Plasticity. Symposium conducted at the 64th Annual Scientific Meeting of the Gerontological Society of America, Boston, MA.

Abstract: 

Objective: The terminal cognitive decline hypothesis has been debated for almost 50 years. This hypothesis implies a change in rate of decline within an individual. Therefore, we examine the hypothesis from a within-person perspective using a time to death chronological structure.

Method: Scores on a Swedish version of the Wechsler Adult Intelligence Scale Information and Block Design scores from 461 OCTO-Twin Study participants with confirmed death dates were modeled using quadratic growth curve models including both age and distance from death at study entry, sex, education, and dementia diagnosis as covariates of initial performance and of linear and quadratic change over time.

Results: Information scores showed statistically significant evidence of slight within-person acceleration of declines in the no dementia group. Individuals with incident dementia declined more quickly, and those who were closer to death at study baseline had a stronger acceleration. Block Design scores declined but did not show evidence of such acceleration either within or across individuals: Decline was faster in incident cases closer to death at study entry.

Discussion. Within-person evidence of terminal decline is not as strong as previously published between-person results. Strategies for focusing models on longitudinal aspects of available data and the extent to which lack of within-person evidence for terminal decline may stem from common data limitations are discussed.

Van den Kommer et al., 2010. Classification models for early identification of persons at risk for dementia in primary care: An evaluation in a sample aged 80 years and older

Van den Kommer, T. N., Bontempo, D. E., Comijs, H. C., Hofer, S. M., Dik, M. G., Piccinin, A. M., Jonker, C., Deeg, D. J. H., & Johansson, B. (2010). Classification models for early identification of persons at risk for dementia in primary care: An evaluation in a sample aged 80 years and older, Dementia and Geriatric Cognitive Disorders, 28(6), 567-577.

Year: 
2010
Status: 
complete
Abstract: 

Aim: To evaluate previously developed classification models to make implementation in primary care possible and aid early identification of persons at risk for dementia. Methods: Data were drawn from the OCTO-Twin study. At baseline, 521 persons ≧80 years of age were nondemented, and for 387 a blood sample was available. Predictors of dementia were collected and analyzed in initially nondemented persons using generalized estimating equations and Cox survival analyses. Results: In the basic model using predictors already known or easily obtained (basic set), the mean 2-year predictive value increased from 6.9 to 28.8% in persons with memory complaints and an MMSE score ≤25. In the extended model, using both the basic set and an extended set of predictors requiring further assessment, the 8-year predictive value increased from 15.0 to 45.8% in persons with low cholesterol and an MMSE score ≤24. Conclusion: Both models can contribute to an improved early identification of persons at risk for dementia in primary care.

Hoffman et al., 2008. Individual Differences In Cognitive Decline

Year: 
2008
Status: 
complete
Presentation Citations: 

Hoffman, L., Hofer, S. M., Johansson, B. (2008, November). Individual differences in cognitive decline in persons with and without dementia. Poster presented at the annual Gerontological Society of America Conference, Baltimore, MD.

Comijs et al., 2009. Classification models for early identification of persons at risk for dementia, a replication study.

Year: 
2009
Status: 
complete
Presentation Citations: 

Comijs, H. Van Den Kommer, T. N., Bontempo, D. E., Hofer, S. M., Dik, M., Piccinin, A. M., Deeg, D. J., & Johansson, B. (2009, November). Classification models for early identification of persons at risk for dementia, a replication study.  In S. M. Hofer (Chair), Coordinated and pooled data analyses of longitudinal studies of aging: Aging and dementia-related change in cognition, affect, and physical functioning. Paper symposium conducted at the annual meeting of the Gerontological Society of America, Atlanta.

Abstract: 

Background: The goal of the present study is to develop a classification model for use in primary care using markers which are relatively easy to determine to aid early identification of persons at risk for dementia. 

Methods: Data were used from the Origins of Variance in the Old-Old (OCTO-Twin) study. The baseline sample included 521 non-demented subjects aged 80 and older. Relevant predictors on dementia were collected two years prior to dementia diagnosis. Dementia diagnosis was based on DSM-III-R criteria. Data were analyzed using generalized estimating equations and Cox survival analyses. 

Results: Overall, the two-year incidence of dementia was 6.9%. Reporting memory complaints was the strongest predictor of dementia. Memory complaints and a MMSE score ≤ 25 resulted in a predictive value for dementia of 28.8%. No memory complaints, drinking no alcohol and a MMSE score ≤ 24 resulted in a predictive value of 18.0%. Reporting no memory complaints, drinking alcohol, having functional limitations and a MMSE score ≤ 24 resulted in a percentage of 24.7% identified with dementia after two years of follow-up. 

Conclusions: The developed classification tree could contribute to early identification of persons at risk for dementia in primary care in a feasible and cost-effective way.

 

Dodge et al., 2017. Cohort effects in verbal memory function and practice effects: a population-based study.

Dodge, H. H., Zhu, J., Hughes, T. F., Snitz, B. E., Chang, C. C. H., Jacobsen, E. P., & Ganguli, M. (2017). Cohort effects in verbal memory function and practice effects: a population-based study. International psychogeriatrics, 29(1), 137-148.

Year: 
2017
Status: 
complete
Abstract: 

Background: In many developed countries, cognitive functioning (as measured by neuropsychological tests) appears to be improving over time in the population at large, in parallel with the declining age-specific incidence of dementia. Here, we investigated cohort effects in the age-associated trajectories of verbal memory function in older adults. We sought to determine whether they varied by decade of birth and, if so, whether the change would be explained by increasing educational attainment.

Methods: Pooling data from two prospective US population-based studies between 1987 and 2015, we identified four birth cohorts born 1902–1911, 1912–1921, 1922–1931, and 1932–1943. Among these cohorts, we compared age-associated trajectories both of performance and of practice effects on immediate and delayed recall of a 10-item Word List. We used mixed effects models, first including birth cohorts and cohort X age interaction terms, and then controlling for education and education X age interaction.

Results: We observed significant cohort effects in performance (baseline and age-associated trajectories) in both immediate recall and delayed recall, with function improving between the earliest- and latest-born cohorts. For both tests, we also observed cohort effects on practice effects with the highest levels in the latest-born cohorts. Including education in the models did not attenuate these effects.

Conclusions: In this longitudinal population study, across four decade-long birth cohorts, there were significant improvements in test performance and practice effects in verbal memory tests, not explained by education. Whether this reflects declining disease incidence or other secular trends awaits further investigation.