| 1. |
- Josefsson, Maria, 1979-, et al.
(author)
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Genetic and Lifestyle Predictors of 15-Year Longitudinal Change in Episodic Memory
- 2012
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In: Journal of The American Geriatrics Society. - : Wiley. - 0002-8614 .- 1532-5415. ; 60:12, s. 2308-2312
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Journal article (peer-reviewed)abstract
- Objectives: To reveal distinct longitudinal trajectories in episodic memory over 15 years and to identify demographic, lifestyle, health-related, and genetic predictors of stability or decline. Design: Prospective cohort study. Setting: The Betula Project, Umeå, Sweden. Participants: One thousand nine hundred fifty-four healthy participants aged 35 to 85 at baseline. Measurements: Memory was assessed according to validated episodic memory tasks in participants from a large population-based sample. Data were analyzed using a random-effects pattern-mixture model that considered the effect of attrition over two to four longitudinal sessions. Logistic regression was used to determine significant predictors of stability or decline relative to average change in episodic memory. Results: Of 1,558 participants with two or more test sessions, 18% were classified as maintainers and 13% as decliners, and 68% showed age-typical average change. More educated and more physically active participants, women, and those living with someone were more likely to be classified as maintainers, as were carriers of the met allele of the catechol-O-methyltransferase gene. Less educated participants, those not active in the labor force, and men were more likely to be classified as decliners, and the apolipoprotein E ɛ4 allele was more frequent in decliners. Conclusion: Quantitative, attrition-corrected assessment of longitudinal changes in memory can reveal substantial heterogeneity in aging trajectories, and genetic and lifestyle factors predict such heterogeneity.
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| 2. |
- Vestergren, Peter, 1974-, et al.
(author)
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Development of the cognitive dysfunction questionnaire (CDQ) in a population based sample
- 2011
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In: Scandinavian Journal of Psychology. - Stockholm : Almqvist & Wiksell. - 0036-5564 .- 1467-9450. ; 52:3, s. 218-228
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Journal article (peer-reviewed)abstract
- The study reports on the development of a questionnaire for assessment of adult cognitive dysfunction (CDQ). Participants in a population-based sample(65 ± 15 years, N = 370) responded to a 90-item pilot version covering multiple aspects of memory/cognition. Based on exploratory principal components analyses and correlations with criterion measures of cognitive functioning (MMSE, Block Design, semantic/episodic memory), 20 items loading on 6 components were selected for the final version of the questionnaire. Cronbach’s a for the total score was 0.90. There was evidence of construct validity as judged by correlations between CDQ scores, objective cognitive measures, and a subjective memory measure (PRMQ). Discriminant validity was demonstrated by a low and non-significant correlation with depressive symptoms. Further evidence of construct validity was provided by correlations with age and educational attainment. In conclusion, the CDQ is promising as a self-rating screening tool for cognitive dysfunction, and will be the subject of further development and validation.
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| 3. |
- Vestergren, Peter, 1974-, et al.
(author)
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Multigroup confirmatory factor analysis of the cognitive dysfunction questionnaire : instrument refinement and measurement invariance across age and sex
- 2012
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In: Scandinavian Journal of Psychology. - : Wiley-Blackwell. - 0036-5564 .- 1467-9450. ; 53:5, s. 390-400
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Journal article (peer-reviewed)abstract
- The study adopted CFA to investigate the factorial structure and reduce the number of items of the Cognitive Dysfunction Questionnaire (CDQ; Vestergren, Rönnlund, Nyberg, & Nilsson, 2011). The analyses were based on data for a total of 1115 participants from population based samples (mean age: 63.0 ± 14.5 years, range: 25 - 95) randomly split into a refinement (n = 569) and a cross-validation (n = 546) sample. Equivalence of the measurement and structural portions of the refined model was demonstrated across the refinement and cross-validation samples. Among competing models the best fitting and parsimonious model had a hierarchical factor structure with five first-order and one second-order general factor. The final version of the CDQ consisted of 20 items in five domains (Procedural actions, Semantic word knowledge, Face recognition, Temporal orientation and Spatial navigation). Internal consistency reliabilities were adequate for the total scale and for the subscales. Multigroup CFAs were performed and the results indicate measurement invariance across age and sex up to the scalar level. Finally, higher levels of cognitive dysfunction as reflected by CDQ scores were observed with advancing age and with deficits in general cognitive functioning as reflected by scores on the Mini-Mental State Examination. In conclusion, adoption of the final version of the CDQ appears to be a way of measuring cognitive dysfunction without administering formal cognitive tests. Future studies should apply it among clinical groups to further test its usefulness.
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| 4. |
- Habib, Reza, et al.
(author)
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Cognitive and non-cognitive factors contributing to the longitudinal identification of successful older adults in the Betula study.
- 2007
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In: Aging, Neuropsychology and Cognition.. - Lisse : Swets & Zeitlinger. ; 14:3, s. 257-273
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Journal article (peer-reviewed)abstract
- Studies of successful aging have typically defined elderly who fall in the upper end of a distribution of test scores as successful. A different definition of successful aging requires that older adults fall at or above the mean level of younger adults and maintain this level over time. Here we examined this definition of successful aging in a sample of 1463 individuals between 50 to 85 years of age. Based on principal coordinate analysis of cognitive and non-cognitive variables, we identified a group of 55 (8.3%) 70-85 years olds that were high functioning. This group of elderly showed elevated performance on a range of cognitive tasks. Non-cognitive factors that characterized this group included education and subjective health. The participants were re-tested 5 years later and the same type of analysis was repeated. Of the remaining individuals who initially were classified as high functioning, 18 (35%) remained high functioning and thus met the definition for successful aging. Years of education was a significant predictor of who remained successful over time.
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| 5. |
- Hedner, Margareta, et al.
(author)
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Age-Related Olfactory Decline is Associated with the BDNF Val66met Polymorphism : Evidence from a Population-Based Study
- 2010
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In: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 2:7, s. 24-
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Journal article (peer-reviewed)abstract
- The present study investigates the effect of the brain-derived neurotrophic factor (BDNF) val66met polymorphism on change in olfactory function in a large scale, longitudinal population-based sample (n = 836). The subjects were tested on a 13 item force-choice odor identification test on two test occasions over a 5-year-interval. Sex, education, health-related factors, and semantic ability were controlled for in the statistical analyses. Results showed an interaction effect of age and BDNF val66met on olfactory change, such that the magnitude of olfactory decline in the older age cohort (70–90years old at baseline) was larger for the val homozygote carriers than for the met carriers. The older met carriers did not display larger age-related decline in olfactory function compared to the younger group. The BDNF val66met polymorphism did not affect the rate of decline in the younger age cohort (45–65years). The findings are discussed in the light of the proposed roles of BDNF in neural development and maintenance.
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| 6. |
- Lind, Johanna, et al.
(author)
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Reduced functional brain activity response in cognitively intact apolipoprotein E ε4 carriers
- 2006
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In: Brain. - : Oxford University Press. - 0006-8950 .- 1460-2156. ; 129:5, s. 1240-1248
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Journal article (peer-reviewed)abstract
- The apolipoprotein E epsilon4 (APOE epsilon4) is the main known genetic risk factor for Alzheimer's disease. Genetic assessments in combination with other diagnostic tools, such as neuroimaging, have the potential to facilitate early diagnosis. In this large-scale functional MRI (fMRI) study, we have contrasted 30 APOE epsilon4 carriers (age range: 49-74 years; 19 females), of which 10 were homozygous for the epsilon4 allele, and 30 non-carriers with regard to brain activity during a semantic categorization task. Test groups were closely matched for sex, age and education. Critically, both groups were cognitively intact and thus symptom-free of Alzheimer's disease. APOE epsilon4 carriers showed reduced task-related responses in the left inferior parietal cortex, and bilaterally in the anterior cingulate region. A dose-related response was observed in the parietal area such that diminution was most pronounced in homozygous compared with heterozygous carriers. In addition, contrasts of processing novel versus familiar items revealed an abnormal response in the right hippocampus in the APOE epsilon4 group, mainly expressed as diminished sensitivity to the relative novelty of stimuli. Collectively, these findings indicate that genetic risk translates into reduced functional brain activity, in regions pertinent to Alzheimer's disease, well before alterations can be detected at the behavioural level.
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| 7. |
- Lind, Johanna, et al.
(author)
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Reduced hippocampal volume in non-demented carriers fo the apolipoprotein E ε4 : Relation to chronological age and recognition memory
- 2006
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In: Neuroscience Letters. - : Elsevier BV. - 0304-3940 .- 1872-7972. ; 396:1, s. 23-27
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Journal article (peer-reviewed)abstract
- Apolipoprotein E ε4 (APOE ε4) is the main known genetic risk factor for Alzheimer's disease (AD). Some previous studies have reported structural brain changes as well as cognitive deficits in non-demented APOE ε4 carriers, but the pattern of results is inconsistent and studies with larger sample sizes have been called for. Here we compared hippocampal volume and recognition–memory performance between AD-symptom-free carriers (N = 30) and non-carriers (N = 30) of the APOE ε4 (age range: 49–79 years). We observed reduced right hippocampal volume in APOE ε4 carriers, and found that the difference was most pronounced before the age of 65. Further, the APOE ε4 carriers made significantly more false alarms in the recognition–memory test, and the number of false alarms correlated significantly with right hippocampus volume. These results indicate that relatively young individuals at genetic risk for AD have smaller hippocampal volume and lower performance on hippocampal-dependent cognitive tasks. A question for the future is whether smaller hippocampal volume represents early-onset hippocampal volume reduction or an inherent trait.
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| 8. |
- Naghavi, Hamid Reza, et al.
(author)
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Personality traits predict response to novel and familiar stimuli in the hippocampal region
- 2009
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In: Psychiatry Research. - : Elsevier. - 0165-1781 .- 1872-7123 .- 0925-4927 .- 1872-7506. ; 173:2, s. 94-99
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Journal article (peer-reviewed)abstract
- Current evidence from genetic, neurochemical, and clinical research supports the notion that a combination of high novelty seeking and low harm avoidance traits (NS-ha) is reliably dissociable from the opposite personality profile (i.e., low novelty seeking and high harm avoidance, ns-HA). Little is known, however, about how the differences between these two types of personality are regulated by brain function. Here we used functional magnetic resonance imaging (fMRI) and recruited two groups of individuals, one group with the NS-ha profile and the other group with the ns-HA profile, to examine whether there is a difference between the two groups in their brain response to novel versus familiar word stimuli. Results revealed a differential pattern of response in an area in the hippocampal region, with the NS-ha group showing a greater sensitivity to novel stimuli and the ns-HA group demonstrating a greater response to familiar stimuli. We conclude that the response pattern to novel and familiar stimuli in the hippocampal region has a role in mediating differences between the NS-ha and ns-HA temperamental profiles.
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| 9. |
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| 10. |
- Olofsson, Jonas K., et al.
(author)
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Odor Identification Deficit as a Predictor of Five-Year Global Cognitive Change : Interactive Effects with Age and ApoE-ε4
- 2009
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In: Behavior Genetics. - : Springer Netherlands. - 0001-8244 .- 1573-3297. ; 39:5, s. 496-503
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Journal article (peer-reviewed)abstract
- Olfactory impairments are present in common neurodegenerative disorders and predict conversion to dementia in non-demented individuals with cognitive impairment. In cognitively intact elderly, evidence is sparse regarding the role of olfactory deficits in predicting cognitive impairment. The present study investigated predictors of 5-year prospective decline in the Mini-Mental State Examination (MMSE) in a large (n = 501), population-based sample of elderly (65–90 years) individuals. All participants were genotyped for the ApoE gene, assessed for health factors, and were non-demented at the baseline assessment. After partialling out the influences of demographic and health-factors at baseline and dementia at follow-up, poor odor identification ability in combination with older age and the ApoE-ε4 allele predicted larger prospective global cognitive decline. This effect could not be produced by a vocabulary test. In sum, the findings suggest that an olfactory deficit can dissociate between benign and malign global cognitive development in non-demented, very old ε4-carriers, who are at high risk of developing dementia.
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