| 1. |
- Binnewies, Julia, et al.
(författare)
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Associations of depression and regional brain structure across the adult lifespan : Pooled analyses of six population-based and two clinical cohort studies in the European Lifebrain consortium
- 2022
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Ingår i: NeuroImage. - : Elsevier. - 2213-1582. ; 36
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Major depressive disorder has been associated with lower prefrontal thickness and hippocampal volume, but it is unknown whether this association also holds for depressive symptoms in the general population. We investigated associations of depressive symptoms and depression status with brain structures across population-based and patient-control cohorts, and explored whether these associations are similar over the lifespan and across sexes.Methods: We included 3,447 participants aged 18–89 years from six population-based and two clinical patient-control cohorts of the European Lifebrain consortium. Cross-sectional meta-analyses using individual person data were performed for associations of depressive symptoms and depression status with FreeSurfer-derived thickness of bilateral rostral anterior cingulate cortex (rACC) and medial orbitofrontal cortex (mOFC), and hippocampal and total grey matter volume (GMV), separately for population-based and clinical cohorts.Results: Across patient-control cohorts, depressive symptoms and presence of mild-to-severe depression were associated with lower mOFC thickness (rsymptoms = −0.15/ rstatus = −0.22), rACC thickness (rsymptoms = −0.20/ rstatus = −0.25), hippocampal volume (rsymptoms = −0.13/ rstatus = 0.13) and total GMV (rsymptoms = −0.21/ rstatus = −0.25). Effect sizes were slightly larger for presence of moderate-to-severe depression. Associations were similar across age groups and sex. Across population-based cohorts, no associations between depression and brain structures were observed.Conclusions: Fitting with previous meta-analyses, depressive symptoms and depression status were associated with lower mOFC, rACC thickness, and hippocampal and total grey matter volume in clinical patient-control cohorts, although effect sizes were small. The absence of consistent associations in population-based cohorts with mostly mild depressive symptoms, suggests that significantly lower thickness and volume of the studied brain structures are only detectable in clinical populations with more severe depressive symptoms.
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| 2. |
- Fjell, Anders M., et al.
(författare)
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Poor Self-Reported Sleep is Related to Regional Cortical Thinning in Aging but not Memory Decline-Results From the Lifebrain Consortium
- 2021
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Ingår i: Cerebral Cortex. - : Oxford University Press. - 1047-3211 .- 1460-2199. ; 31:4, s. 1953-1969
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Tidskriftsartikel (refereegranskat)abstract
- We examined whether sleep quality and quantity are associated with cortical and memory changes in cognitively healthy participants across the adult lifespan. Associations between self-reported sleep parameters (Pittsburgh Sleep Quality Index, PSQI) and longitudinal cortical change were tested using five samples from the Lifebrain consortium (n = 2205, 4363 MRIs, 18-92 years). In additional analyses, we tested coherence with cell-specific gene expression maps from the Allen Human Brain Atlas, and relations to changes in memory performance. "PSQI # 1 Subjective sleep quality" and "PSQI #5 Sleep disturbances" were related to thinning of the right lateral temporal cortex, with lower quality and more disturbances being associated with faster thinning. The association with "PSQI #5 Sleep disturbances" emerged after 60 years, especially in regions with high expression of genes related to oligodendrocytes and S1 pyramidal neurons. None of the sleep scales were related to a longitudinal change in episodic memory function, suggesting that sleep-related cortical changes were independent of cognitive decline. The relationship to cortical brain change suggests that self-reported sleep parameters are relevant in lifespan studies, but small effect sizes indicate that self-reported sleep is not a good biomarker of general cortical degeneration in healthy older adults.
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| 3. |
- Fjell, Anders M., et al.
(författare)
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Self-reported sleep relates to hippocampal atrophy across the adult lifespan : results from the Lifebrain consortium
- 2020
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Ingår i: Sleep. - : Oxford University Press. - 0161-8105 .- 1550-9109. ; 43:5
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Poor sleep is associated with multiple age-related neurodegenerative and neuropsychiatric conditions. The hippocampus plays a special role in sleep and sleep-dependent cognition, and accelerated hippocampal atrophy is typically seen with higher age. Hence, it is critical to establish how the relationship between sleep and hippocampal volume loss unfolds across the adult lifespan.Methods: Self-reported sleep measures and MRI-derived hippocampal volumes were obtained from 3105 cognitively normal participants (18–90 years) from major European brain studies in the Lifebrain consortium. Hippocampal volume change was estimated from 5116 MRIs from 1299 participants for whom longitudinal MRIs were available, followed up to 11 years with a mean interval of 3.3 years. Cross-sectional analyses were repeated in a sample of 21,390 participants from the UK Biobank.Results: No cross-sectional sleep—hippocampal volume relationships were found. However, worse sleep quality, efficiency, problems, and daytime tiredness were related to greater hippocampal volume loss over time, with high scorers showing 0.22% greater annual loss than low scorers. The relationship between sleep and hippocampal atrophy did not vary across age. Simulations showed that the observed longitudinal effects were too small to be detected as age-interactions in the cross-sectional analyses.Conclusions: Worse self-reported sleep is associated with higher rates of hippocampal volume decline across the adult lifespan. This suggests that sleep is relevant to understand individual differences in hippocampal atrophy, but limited effect sizes call for cautious interpretation.
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| 4. |
- Fjell, Anders M., et al.
(författare)
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The genetic organization of longitudinal subcortical volumetric change is stable throughout the lifespan running title: Genetics of subcortical lifespan change
- 2021
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Ingår i: eLIFE. - : eLife Sciences Publications Ltd. - 2050-084X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Development and aging of the cerebral cortex show similar topographic organization and are governed by the same genes. It is unclear whether the same is true for subcortical regions, which follow fundamentally different ontogenetic and phylogenetic principles. We tested the hypothesis that genetically governed neurodevelopmental processes can be traced throughout life by assessing to which degree brain regions that develop together continue to change together through life. Analyzing over 6000 longitudinal MRIs of the brain, we used graph theory to identify five clusters of coordinated development, indexed as patterns of correlated volumetric change in brain structures. The clusters tended to follow placement along the cranial axis in embryonic brain development, suggesting continuity from prenatal stages, and correlated with cognition. Across independent longitudinal datasets, we demonstrated that developmental clusters were conserved through life. Twin-based genetic correlations revealed distinct sets of genes governing change in each cluster. Single nucleotide polymorphisms-based analyses of 38127 cross-sectional MRIs showed a similar pattern of genetic volume-volume correlations. In conclusion, coordination of subcortical change adheres to fundamental principles of lifespan continuity and genetic organization.
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| 5. |
- Friedman, Barbara Bodorkos, et al.
(författare)
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Are People Ready for Personalized Brain Health? Perspectives of Research Participants in the Lifebrain Consortium
- 2020
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Ingår i: The Gerontologist. - : Oxford University Press. - 0016-9013 .- 1758-5341. ; 60:6, s. E374-E383
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND OBJECTIVES: A healthy brain is central to physical and mental well-being. In this multi-site, qualitative study, we investigated views and attitudes of adult participants in brain research studies on the brain and personalized brain health as well as interest in maintaining a healthy brain.DESIGN AND METHODS: We conducted individual interviews with 44 adult participants in brain research cohorts of the Lifebrain consortium in Spain, Norway, Germany, and the United Kingdom. The interviews were audio recorded, transcribed, and coded using a cross-country codebook. The interview data were analyzed using qualitative content analysis.RESULTS: Most participants did not focus on their own brain health and expressed uncertainty regarding how to maintain it. Those actively focusing on brain health often picked one specific strategy like diet or memory training. The participants were interested in taking brain health tests to learn about their individual risk of developing brain diseases, and were willing to take measures to maintain their brain health if personalized follow-up was provided and the measures had proven impact. The participants were interested in more information on brain health. No differences in responses were identified between age groups, sex, or countries.DISCUSSION AND IMPLICATIONS: Concise, practical, personalized, and evidence-based information about the brain may promote brain health. Based on our findings, we have launched an ongoing global brain health survey to acquire more extensive, quantitative, and representative data on public perception of personalized brain health.
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| 6. |
- Gorbach, Tetiana, 1991-, et al.
(författare)
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Longitudinal association between hippocampus atrophy and episodic-memory decline in non-demented APOE ε4 carriers
- 2020
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Ingår i: Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring. - : John Wiley & Sons. - 2352-8729. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The apolipoprotein E (APOE) ε4 allele is the main genetic risk factor for Alzheimer's disease (AD), accelerated cognitive aging, and hippocampal atrophy, but its influence on the association between hippocampus atrophy and episodic-memory decline in non-demented individuals remains unclear.Methods: We analyzed longitudinal (two to six observations) magnetic resonance imaging (MRI)–derived hippocampal volumes and episodic memory from 748 individuals (55 to 90 years at baseline, 50% female) from the European Lifebrain consortium.Results: The change-change association for hippocampal volume and memory was significant only in ε4 carriers (N = 173, r = 0.21, P = .007; non-carriers: N = 467, r = 0.073,P = .117). The linear relationship was significantly steeper for the carriers [t(629) =2.4, P = .013]. A similar trend toward a stronger change-change relation for carriers was seen in a subsample with more than two assessments.Discussion: These findings provide evidence for a difference in hippocampus-memory association between ε4 carriers and non-carriers, thus highlighting how genetic factors modulate the translation of the AD-related pathophysiological cascade into cognitive deficits.
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| 7. |
- Grydeland, Håkon, et al.
(författare)
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Self-reported sleep relates to microstructural hippocampal decline in beta-amyloid positive Adults beyond genetic risk
- 2021
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Ingår i: Sleep. - : Oxford University Press. - 0161-8105 .- 1550-9109. ; 44:11
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Tidskriftsartikel (refereegranskat)abstract
- Study Objectives: A critical role linking sleep with memory decay and beta-amyloid (A beta) accumulation, two markers of Alzheimer's disease (AD) pathology, may be played by hippocampal integrity. We tested the hypotheses that worse self-reported sleep relates to decline in memory and intra-hippocampal microstructure, including in the presence of A beta.Methods: Two-hundred and forty-three cognitively healthy participants, aged 19-81 years, completed the Pittsburgh Sleep Quality Index once, and two diffusion tensor imaging sessions, on average 3 years apart, allowing measures of decline in intra-hippocampal microstructure as indexed by increased mean diffusivity. We measured memory decay at each imaging session using verbal delayed recall. One session of positron emission tomography, in 108 participants above 44 years of age, yielded 23 A beta positive. Genotyping enabled control for APOE epsilon 4 status, and polygenic scores for sleep and AD, respectively.Results: Worse global sleep quality and sleep efficiency related to more rapid reduction of hippocampal microstructure over time. Focusing on efficiency (the percentage of time in bed at night spent asleep), the relation was stronger in presence of A beta accumulation, and hippocampal integrity decline mediated the relation with memory decay. The results were not explained by genetic risk for sleep efficiency or AD.Conclusions: Worse sleep efficiency related to decline in hippocampal microstructure, especially in the presence of A beta accumulation, and A beta might link poor sleep and memory decay. As genetic risk did not account for the associations, poor sleep efficiency might constitute a risk marker for AD, although the driving causal mechanisms remain unknown.
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| 8. |
- Halaas, Nathalie Bodd, et al.
(författare)
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CSF sTREM2 and Tau Work Together in Predicting Increased Temporal Lobe Atrophy in Older Adults.
- 2020
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Ingår i: Cerebral cortex (New York, N.Y. : 1991). - : Oxford University Press (OUP). - 1460-2199 .- 1047-3211. ; 30:4, s. 2295-2306
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Tidskriftsartikel (refereegranskat)abstract
- Neuroinflammation may be a key factor in brain atrophy in aging and age-related neurodegenerative disease. The objective of this study was to test the association between microglial expression of soluble Triggering Receptor Expressed on Myeloid Cells 2 (sTREM2), as a measure of neuroinflammation, and brain atrophy in cognitively unimpaired older adults. Brain magnetic resonance imagings (MRIs) and cerebrospinal fluid (CSF) sTREM2, total tau (t-tau), phosphorylated181 tau (p-tau), and Aβ42 were analyzed in 115 cognitively unimpaired older adults, classified according to the A/T/(N)-framework. MRIs were repeated after 2 (n = 95) and 4 (n = 62) years. High baseline sTREM2 was associated with accelerated cortical thinning in the temporal cortex of the left hemisphere, as well as bilateral hippocampal atrophy, independently of age, Aβ42, and tau. sTREM2-related atrophy only marginally increased with biomarker positivity across the AD continuum (A-T- #x2292; A+T- #x2292; A+T+) but was significantly stronger in participants with a high level of p-tau (T+). sTREM2-related cortical thinning correlated significantly with areas of high microglial-specific gene expression in the Allen Human Brain Atlas. In conclusion, increased CSF sTREM2 was associated with accelerated cortical and hippocampal atrophy in cognitively unimpaired older participants, particularly in individuals with tau pathology. This suggests a link between neuroinflammation, neurodegeneration, and amyloid-independent tauopathy.
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| 9. |
- Ness, Hedda T., et al.
(författare)
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Reduced Hippocampal-Striatal Interactions during Formation of Durable Episodic Memories in Aging
- 2022
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Ingår i: Cerebral Cortex. - : Oxford University Press. - 1047-3211 .- 1460-2199. ; 32:11, s. 2358-2372
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Tidskriftsartikel (refereegranskat)abstract
- Encoding of durable episodic memories requires cross-talk between the hippocampus and multiple brain regions. Changes in these hippocampal interactions could contribute to age-related declines in the ability to form memories that can be retrieved after extended time intervals. Here we tested whether hippocampal-neocortical- and subcortical functional connectivity (FC) observed during encoding of durable episodic memories differed between younger and older adults. About 48 younger (20-38 years; 25 females) and 43 older (60-80 years; 25 females) adults were scanned with fMRI while performing an associative memory encoding task. Source memory was tested ~20 min and ~6 days postencoding. Associations recalled after 20 min but later forgotten were classified as transient, whereas memories retained after long delays were classified as durable. Results demonstrated that older adults showed a reduced ability to form durable memories and reduced hippocampal-caudate FC during encoding of durable memories. There was also a positive relationship between hippocampal-caudate FC and higher memory performance among the older adults. No reliable age group differences in durable memory-encoding activity or hippocampal-neocortical connectivity were observed. These results support the classic theory of striatal alterations as one cause of cognitive decline in aging and highlight that age-related changes in episodic memory extend beyond hippocampal-neocortical connections.
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| 10. |
- Nyberg, Lars, et al.
(författare)
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Educational attainment does not influence brain aging
- 2021
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 118:18
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Tidskriftsartikel (refereegranskat)abstract
- Education has been related to various advantageous lifetime outcomes. Here, using longitudinal structural MRI data (4,422 observations), we tested the influential hypothesis that higher education translates into slower rates of brain aging. Cross-sectionally, education was modestly associated with regional cortical volume. However, despite marked mean atrophy in the cortex and hippocampus, education did not influence rates of change. The results were replicated across two independent samples. Our findings challenge the view that higher education slows brain aging.
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