| 1. |
- Hibar, D. P., et al.
(författare)
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Cortical abnormalities in bipolar disorder: An MRI analysis of 6503 individuals from the ENIGMA Bipolar Disorder Working Group
- 2018
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Ingår i: Molecular Psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 23:4, s. 932-942
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Tidskriftsartikel (refereegranskat)abstract
- Despite decades of research, the pathophysiology of bipolar disorder (BD) is still not well understood. Structural brain differences have been associated with BD, but results from neuroimaging studies have been inconsistent. To address this, we performed the largest study to date of cortical gray matter thickness and surface area measures from brain magnetic resonance imaging scans of 6503 individuals including 1837 unrelated adults with BD and 2582 unrelated healthy controls for group differences while also examining the effects of commonly prescribed medications, age of illness onset, history of psychosis, mood state, age and sex differences on cortical regions. In BD, cortical gray matter was thinner in frontal, temporal and parietal regions of both brain hemispheres. BD had the strongest effects on left pars opercularis (Cohen's d='0.293; P=1.71 × 10 '21), left fusiform gyrus (d='0.288; P=8.25 × 10 '21) and left rostral middle frontal cortex (d='0.276; P=2.99 × 10 '19). Longer duration of illness (after accounting for age at the time of scanning) was associated with reduced cortical thickness in frontal, medial parietal and occipital regions. We found that several commonly prescribed medications, including lithium, antiepileptic and antipsychotic treatment showed significant associations with cortical thickness and surface area, even after accounting for patients who received multiple medications. We found evidence of reduced cortical surface area associated with a history of psychosis but no associations with mood state at the time of scanning. Our analysis revealed previously undetected associations and provides an extensive analysis of potential confounding variables in neuroimaging studies of BD. © 2018 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
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| 2. |
- Thompson, Paul M., et al.
(författare)
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The ENIGMA Consortium : large-scale collaborative analyses of neuroimaging and genetic data
- 2014
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Ingår i: BRAIN IMAGING BEHAV. - : Springer Science and Business Media LLC. - 1931-7557 .- 1931-7565. ; 8:2, s. 153-182
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Tidskriftsartikel (refereegranskat)abstract
- The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in neuroscience, genetics, and medicine, ENIGMA studies have analyzed neuroimaging data from over 12,826 subjects. In addition, data from 12,171 individuals were provided by the CHARGE consortium for replication of findings, in a total of 24,997 subjects. By meta-analyzing results from many sites, ENIGMA has detected factors that affect the brain that no individual site could detect on its own, and that require larger numbers of subjects than any individual neuroimaging study has currently collected. ENIGMA's first project was a genome-wide association study identifying common variants in the genome associated with hippocampal volume or intracranial volume. Continuing work is exploring genetic associations with subcortical volumes (ENIGMA2) and white matter microstructure (ENIGMA-DTI). Working groups also focus on understanding how schizophrenia, bipolar illness, major depression and attention deficit/hyperactivity disorder (ADHD) affect the brain. We review the current progress of the ENIGMA Consortium, along with challenges and unexpected discoveries made on the way.
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| 3. |
- Hibar, D. P., et al.
(författare)
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Subcortical volumetric abnormalities in bipolar disorder
- 2016
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Ingår i: Molecular Psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 21:12, s. 1710-1716
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Tidskriftsartikel (refereegranskat)abstract
- Considerable uncertainty exists about the defining brain changes associated with bipolar disorder (BD). Understanding and quantifying the sources of uncertainty can help generate novel clinical hypotheses about etiology and assist in the development of biomarkers for indexing disease progression and prognosis. Here we were interested in quantifying case-control differences in intracranial volume (ICV) and each of eight subcortical brain measures: nucleus accumbens, amygdala, caudate, hippocampus, globus pallidus, putamen, thalamus, lateral ventricles. In a large study of 1710 BD patients and 2594 healthy controls, we found consistent volumetric reductions in BD patients for mean hippocampus (Cohen's d=-0.232; P=3.50 × 10 -7) and thalamus (d=-0.148; P=4.27 × 10 -3) and enlarged lateral ventricles (d=-0.260; P=3.93 × 10 -5) in patients. No significant effect of age at illness onset was detected. Stratifying patients based on clinical subtype (BD type I or type II) revealed that BDI patients had significantly larger lateral ventricles and smaller hippocampus and amygdala than controls. However, when comparing BDI and BDII patients directly, we did not detect any significant differences in brain volume. This likely represents similar etiology between BD subtype classifications. Exploratory analyses revealed significantly larger thalamic volumes in patients taking lithium compared with patients not taking lithium. We detected no significant differences between BDII patients and controls in the largest such comparison to date. Findings in this study should be interpreted with caution and with careful consideration of the limitations inherent to meta-analyzed neuroimaging comparisons. © 2016 Macmillan Publishers Limited, part of Springer Nature.
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| 4. |
- Sellgren, C. M., et al.
(författare)
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A genome-wide association study of kynurenic acid in cerebrospinal fluid: implications for psychosis and cognitive impairment in bipolar disorder
- 2016
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Ingår i: Molecular Psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 21:10, s. 1342-1350
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Tidskriftsartikel (refereegranskat)abstract
- Elevated cerebrospinal fluid (CSF) levels of the glia-derived N-methyl-D-aspartic acid receptor antagonist kynurenic acid (KYNA) have consistently been implicated in schizophrenia and bipolar disorder. Here, we conducted a genome-wide association study based on CSF KYNA in bipolar disorder and found support for an association with a common variant within 1p21.3. After replication in an independent cohort, we linked this genetic variant-associated with reduced SNX7 expression-to positive psychotic symptoms and executive function deficits in bipolar disorder. A series of post-mortem brain tissue and in vitro experiments suggested SNX7 downregulation to result in a caspase-8-driven activation of interleukin-1 beta and a subsequent induction of the brain kynurenine pathway. The current study demonstrates the potential of using biomarkers in genetic studies of psychiatric disorders, and may help to identify novel drug targets in bipolar disorder.
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| 5. |
- Johansson, Viktoria, et al.
(författare)
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Microscopic Particles in Two Fractions of Fresh Cerebrospinal Fluid in Twins with Schizophrenia or Bipolar Disorder and in Healthy Controls
- 2012
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 7:9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Using scanning electron microscopy, microscopic structures have been identified in fresh cerebrospinal fluid (CSF) in patients with schizophrenia and bipolar disorder, but only rarely in control subjects. However, it has not been determined whether these microscopic particles represent state or trait markers, i.e. if their presence is related to clinical manifestations of the disease or if they also can be found in as yet asymptomatic individuals with a genetic liability. This question can be addressed by studying twins discordant or concordant for schizophrenia or bipolar disorder. Methodology/Principal Findings: We investigated microscopic structures in CSF in 102 individuals: 21 monozygotic and 16 dizygotic twins affected or not affected with schizophrenia, schizoaffective disorder or bipolar disorder and in 65 healthy singleton controls. A first and a second fraction of CSF was freshly applied on filters and examined by scanning electron microscopy technique. Spherical particles with lipid appearance averaging between 0.1 to 8.0 mu m in diameter were detected in the center of the filter as well as located in the margins of larger aggregates binding in a viscous state. Structures were found in 12 of 17 probands, 5 of 12 healthy co-twins and 3 of 73 healthy controls. Thus, a positive microscopic finding significantly increased the likelihood of belonging to the proband group (OR = 48, 95% CL: 8.2-550, p<0.0001) and the co-twin-group (OR = 16, 95% CL: 2.0-218, p = 0.006). Age, sex, history of alcohol abuse or anxiety syndrome, somatic disorder and markers of acute inflammatory activity did not account for group differences; nor did exposure to psychotropic medication. Conclusion: Presence of microscopic particles in CSF may possibly reflect trait dependent genetic or environmental vulnerability in patients with schizophrenia, schizoaffective disorder or bipolar disorder.
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| 6. |
- Abé, C, et al.
(författare)
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Bipolar disorder type I and II show distinct relationships between cortical thickness and executive function.
- 2018
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Ingår i: Acta psychiatrica Scandinavica. - : Wiley. - 1600-0447 .- 0001-690X. ; 138:4, s. 325-335
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Tidskriftsartikel (refereegranskat)abstract
- Frontal cortical abnormalities and executive function impairment co-occur in bipolar disorder. Recent studies have shown that bipolar subtypes differ in the degree of structural and functional impairments. The relationships between cognitive performance and cortical integrity have not been clarified and might differ across patients with bipolar disorder type I, II, and healthy subjects.Using a vertex-wise whole-brain analysis, we investigated how cortical integrity, as measured by cortical thickness, correlates with executive performance in patients with bipolar disorder type I, II, and controls (N = 160).We found focal associations between executive function and cortical thickness in the medial prefrontal cortex in bipolar II patients and controls, but not in bipolar I disorder. In bipolar II patients, we observed additional correlations in lateral prefrontal and occipital regions.Our findings suggest that bipolar disorder patients show altered structure-function relationships, and importantly that those relationships may differ between bipolar subtypes. The findings are line with studies suggesting subtype-specific neurobiological and cognitive profiles. This study contributes to a better understanding of brain structure-function relationships in bipolar disorder and gives important insights into the neuropathophysiology of diagnostic subtypes.
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| 7. |
- Abé, Christoph, et al.
(författare)
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Longitudinal Cortical Thickness Changes in Bipolar Disorder and the Relationship to Genetic Risk, Mania, and Lithium Use.
- 2020
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Ingår i: Biological psychiatry. - : Elsevier BV. - 1873-2402 .- 0006-3223. ; 87:3, s. 271-281
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Tidskriftsartikel (refereegranskat)abstract
- Bipolar disorder (BD) is a highly heritable psychiatric disorder characterized by episodes of manic and depressed mood states and associated with cortical brain abnormalities. Although the course of BD is often progressive, longitudinal brain imaging studies are scarce. It remains unknown whether brain abnormalities are static traits of BD or result from pathological changes over time. Moreover, the genetic effect on implicated brain regions remains unknown.Patients with BD and healthy control (HC) subjects underwent structural magnetic resonance imaging at baseline (123 patients, 83 HC subjects) and after 6 years (90 patients, 61 HC subjects). Cortical thickness maps were generated using FreeSurfer. Using linear mixed effects models, we compared longitudinal changes in cortical thickness between patients with BD and HC subjects across the whole brain. We related our findings to genetic risk for BD and tested for effects of demographic and clinical variables.Patients showed abnormal cortical thinning of temporal cortices and thickness increases in visual/somatosensory brain areas. Thickness increases were related to genetic risk and lithium use. Patients who experienced hypomanic or manic episodes between time points showed abnormal thinning in inferior frontal cortices. Cortical changes did not differ between diagnostic BD subtypes I and II.In the largest longitudinal BD study to date, we detected abnormal cortical changes with high anatomical resolution. We delineated regional effects of clinical symptoms, genetic factors, and medication that may explain progressive brain changes in BD. Our study yields important insights into disease mechanisms and suggests that neuroprogression plays a role in BD.
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| 8. |
- Ahmad, I., et al.
(författare)
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Validity of diagnoses, treatment dates, and rating scales in the Swedish national quality register for electroconvulsive therapy
- 2022
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Ingår i: Nordic Journal of Psychiatry. - : Informa UK Limited. - 0803-9488 .- 1502-4725. ; 76:2, s. 96-103
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Tidskriftsartikel (refereegranskat)abstract
- Background The Swedish national quality register for electroconvulsive therapy (Q-ECT) contains data on patients receiving treatment with electroconvulsive therapy (ECT) in Sweden. Aim This study determined the validity of diagnoses, treatment dates, and rating scales in the Q-ECT by investigating the degree of accordance between data from the Q-ECT and patient records. Materials and methods From January 2016 to December 2017, 200 treatment series were randomly selected from the Q-ECT. The corresponding patient records were requested from the treating hospitals. Data on the indicative diagnosis, dates for the first and the last ECT session, and rating scales were compared between the Q-ECT and patient records using (i) a strict and (ii) a liberal method of assessment. Using the liberal method, each variable was assessed as accordant if it belonged to the same diagnosis group, or if the dates differed by less than 1 week, or ratings differed by only 1 point on the Clinical Global Impression Scale (CGI- S), or no more than 3 points on the Montgomery angstrom sberg Depression Rating Scale between the Q-ECT and the patient record. Results A total of 179 patient records were received. The strict method of assessment showed an accordance of 89% or higher for all studied variables. The liberal method showed an accordance of 95% or higher. Conclusions We conclude that data on the studied variables in the Q-ECT have high validity. However, limited use of some rating scales makes the results uncertain. Measures can be taken to further improve the data quality.
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| 9. |
- Ekman, Carl Johan, et al.
(författare)
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A History of Psychosis in Bipolar Disorder is Associated With Gray Matter Volume Reduction.
- 2017
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Ingår i: Schizophrenia bulletin. - : Oxford University Press (OUP). - 1745-1701 .- 0586-7614. ; 43:1, s. 99-107
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Tidskriftsartikel (refereegranskat)abstract
- Psychotic symptoms are prevalent in schizophrenia, bipolar disorder, and other psychiatric and neurological disorders, yet the neurobiological underpinnings of psychosis remain obscure. In the last decade, a large number of magnetic resonance imaging studies have shown differences in local gray matter volume between patients with different psychiatric syndromes and healthy controls. Few studies have focused on the symptoms, which these syndromes are constituted of. Here, we test the association between psychosis and gray matter volume by using a sample of 167 subjects with bipolar disorder, with and without a history of psychosis, and 102 healthy controls. Magnetic resonance images were analyzed on group level using a voxel-wise mass univariate analysis (Voxel-Based Morphometry). We found that patients with a history of psychosis had smaller gray matter volume in left fusiform gyrus, the right rostral dorsolateral prefrontal cortex, and the left inferior frontal gyrus compared with patients without psychosis and with healthy controls. There was no volume difference in these areas between the no-psychosis group and healthy controls. These areas have previously been structurally and functionally coupled to delusions and hallucinations. Our finding adds further evidence to the probability of these regions as key areas in the development of psychotic symptoms.
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| 10. |
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