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- Landén, Mikael, 1966, et al.
(författare)
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Brain aging in major depressive disorder: results from the ENIGMA major depressive disorder working group
- 2021
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Ingår i: Molecular Psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 26, s. 5124-5139
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Tidskriftsartikel (refereegranskat)abstract
- Major depressive disorder (MDD) is associated with an increased risk of brain atrophy, aging-related diseases, and mortality. We examined potential advanced brain aging in adult MDD patients, and whether this process is associated with clinical characteristics in a large multicenter international dataset. We performed a mega-analysis by pooling brain measures derived from T1-weighted MRI scans from 19 samples worldwide. Healthy brain aging was estimated by predicting chronological age (18–75 years) from 7 subcortical volumes, 34 cortical thickness and 34 surface area, lateral ventricles and total intracranial volume measures separately in 952 male and 1236 female controls from the ENIGMA MDD working group. The learned model coefficients were applied to 927 male controls and 986 depressed males, and 1199 female controls and 1689 depressed females to obtain independent unbiased brain-based age predictions. The difference between predicted “brain age” and chronological age was calculated to indicate brain-predicted age difference (brain-PAD). On average, MDD patients showed a higher brain-PAD of +1.08 (SE 0.22) years (Cohen’s d = 0.14, 95% CI: 0.08–0.20) compared with controls. However, this difference did not seem to be driven by specific clinical characteristics (recurrent status, remission status, antidepressant medication use, age of onset, or symptom severity). This highly powered collaborative effort showed subtle patterns of age-related structural brain abnormalities in MDD. Substantial within-group variance and overlap between groups were observed. Longitudinal studies of MDD and somatic health outcomes are needed to further assess the clinical value of these brain-PAD estimates. © 2020, The Author(s).
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| 2. |
- Wohlfarth, B, et al.
(författare)
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Unstable early-Holocene climatic and environmental conditions in northwestern Russia derived from a multidisciplinary study of a lake-sediment sequence from Pichozero, southeastern Russian Karelia
- 2004
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Ingår i: The Holocene. - : SAGE Publications. - 0959-6836 .- 1477-0911. ; 14:5, s. 732-746
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Tidskriftsartikel (refereegranskat)abstract
- A sediment core from Lake Pichozero (61degrees46'; N, 37degrees25'; E 118 m a.s.l.) provides information on the environmental and climatic conditions in southeastern Russian Karelia during the Lateglacial and early Holocene (12800-9300 cal. BP). The chronology of the sequence is constrained by varve counting and AMS C-14 measurement of terrestrial plant macrofossils. Multiproxy analyses (magnetic susceptibility, grain size, TOC, TN, TS, Rock Eval, pollen and macrofossils) imply that cold and dry regional climatic conditions with sparse Arctic vegetation prevailed prior to 11500 cal. BP. Coincident with the transition to the Holocene at 11500 cal. BP, air temperatures and lake productivity increased and Betula pubescens and Populus tremula started to migrate into the area, followed by Picea abies at 10750 cal. BP. Although lake productivity decreased at around 11000 cal. BP and remained low until 9600 cal. BP, pollen-based climate reconstructions imply variable climatic conditions in the region over time. Drier and colder summers prevailed from similar to11200 to 10900 cal. BP, followed by an interval of higher annual temperatures and precipitation from 10900 to 10750 cal. BP. Lower annual temperatures and drier conditions existed from 10750 to 10200 cal. BP, and higher temperatures and precipitation are inferred between 10200 and 10000 cal. BP. Finally, declining temperatures and precipitation occurred from 10000 cal. BP onwards, with a minimum at around 9600 cal. BP. These climatic shifts are temporally coincident with those recorded in North Atlantic terrestrial, marine and ice-core archives and indicate that relatively minor climate signals were transmitted further to the east.
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