| 191. |
- Johansson, Viktoria, et al.
(författare)
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A population-based heritability estimate of bipolar disorder - In a Swedish twin sample
- 2019
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Ingår i: Psychiatry Research. - : Elsevier. - 0165-1781 .- 1872-7123. ; 278, s. 180-187
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Tidskriftsartikel (refereegranskat)abstract
- Twin- and family studies have shown variations in the heritability estimates of bipolar disorder (BPD). The current study uses an updated statistical methodology for heritability estimation in BPD by taking available time of follow-up into account while controlling for co-variates. We identified monozygotic and dizygotic same and different sex twins with BPD (n = 804) or unaffected from BPD (n = 91,604) from the Swedish Twin Register and the National Patient Register. We applied structural equational modeling with inversed probability weighting to estimate the heritability, taking into account censoring and truncation of data. Sex-limitation models were constructed to analyze qualitative or quantitative sex-differences in BPD. Heritability for BPD was 60.4% (95% Confidence Interval: 50.3-70.5) after age, sex, left-hand truncation and censoring of the data was taken into account. A larger proportion of females were affected from BPD (females 62.2%; males 37.8%, p < 0.001), but no sex-difference in BPD heritability was found, nor any sex-specific genetic effects. We demonstrated a robust 60% heritability for BPD with no evidence of sex-specific genetic effects on disease liability.
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| 192. |
- Johansson, Viktoria, et al.
(författare)
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Cerebrospinal fluid microglia and neurodegenerative markers in twins concordant and discordant for psychotic disorders.
- 2017
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Ingår i: European Archives of Psychiatry and Clinical Neuroscience. - : Springer. - 0940-1334 .- 1433-8491. ; 267:5, s. 391-402
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Tidskriftsartikel (refereegranskat)abstract
- Schizophrenia and bipolar disorder are debilitating psychiatric disorders with partially shared symptomatology including psychotic symptoms and cognitive impairment. Aberrant levels of microglia and neurodegenerative cerebrospinal fluid (CSF) markers have previously been found in schizophrenia and bipolar disorder. We aimed to analyze familial and environmental influences on these CSF markers and their relation to psychiatric symptoms and cognitive ability. CSF was collected from 17 complete twin pairs, nine monozygotic and eight dizygotic, and from one twin sibling. Two pairs were concordant for schizophrenia, and 11 pairs discordant for schizophrenia, schizoaffective disorder or bipolar disorder, and four pairs were not affected by psychotic disorders. Markers of microglia activation [monocyte chemoattractant protein-1 (MCP-1), chitinase 3-like protein 1 (YKL-40), and soluble cluster of differentiation 14 (sCD14)], markers of β-amyloid metabolism (AβX-38, AβX-40, AβX-42 and Aβ1-42), soluble amyloid precursor proteins (sAPP-α and sAPP-β), total tau (T-tau), phosphorylated tau (P-tau), and CSF/serum albumin ratio were measured in CSF using immunoassays. Heritability of the CSF markers was estimated, and associations to psychiatric and cognitive measurements were analyzed. Heritability estimates of the microglia markers were moderate, whereas several neurodegenerative markers showed high heritability. In contrast, AβX-42, Aβ1-42, P-tau and CSF/serum albumin ratio were influenced by dominant genetic variation. Higher sCD14 levels were found in twins with schizophrenia or bipolar disorder compared to their not affected co-twins, and higher sCD14-levels were associated with psychotic symptoms. The study provides support for a significant role of sCD14 in psychotic disorders and a possible role of microglia activation in psychosis.
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| 193. |
- 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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| 194. |
- Johansson, Viktoria, et al.
(författare)
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The schizophrenia and bipolar twin study in Sweden (STAR)
- 2019
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Ingår i: Schizophrenia Research. - : Elsevier. - 0920-9964 .- 1573-2509. ; 204, s. 183-192
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Tidskriftsartikel (refereegranskat)abstract
- The schizophrenia and bipolar twin study in Sweden (STAR) is a large nation-wide cohort of monozygotic (MZ) and dizygotic (DZ) same-sex twins with schizophrenia or bipolar disorder and healthy control pairs, extensively characterized with brain imaging, neuropsychological tests, biomarkers, genetic testing, psychiatric symptoms and personality traits. The purpose is to investigate genetic and environmental mechanisms that give rise to schizophrenia and bipolar disorder as well as the intermediate phenotypes. This article describes the design, recruitment, data collection, measures, collected twins' characteristics, diagnostic procedures as well as ongoing and planned analyses. Identification of biomarkers, genetic and epigenetic variation and the development of specific and common endophenotypes for schizophrenia and bipolar disorder are potential gains from this cohort.
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| 195. |
- Johansson, Viktoria, et al.
(författare)
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Twin study shows association between monocyte chemoattractant protein-1 and kynurenic acid in cerebrospinal fluid
- 2020
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Ingår i: European Archives of Psychiatry and Clinical Neuroscience. - : Springer Science and Business Media LLC. - 0940-1334 .- 1433-8491. ; 270:7, s. 933-938
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Tidskriftsartikel (refereegranskat)abstract
- Preclinical studies indicate a link between the kynurenine pathway and monocyte chemoattractant protein-1 (MCP-1), but there is a lack of clinical studies examining this further. We here perform a secondary analysis of kynurenine metabolites and MCP-1 in cerebrospinal fluid of 23 twins affected from schizophrenia, bipolar disorder or unaffected. We show an association between MCP-1 and kynurenic acid (KYNA), driven by unique environmental influences and a less pronounced association between MCP-1 and tryptophan. No association was detected between MCP-1 and quinolinic acid. Further studies on the mechanism behind the putative relationship between KYNA and MCP-1 are needed. © 2019, The Author(s).
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| 196. |
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| 197. |
- Kegel, Magdalena E., et al.
(författare)
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Kynurenic acid and psychotic symptoms and personality traits in twins with psychiatric morbidity
- 2017
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Ingår i: Psychiatry Research. - : Elsevier. - 0165-1781 .- 1872-7123. ; 247, s. 105-112
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Tidskriftsartikel (refereegranskat)abstract
- Increased cytokines and kynurenic acid (KYNA) levels in cerebrospinal fluid (CSF) have been reported in patients with schizophrenia and bipolar disorder. The aim of the present study was to investigate cytokines and kynurenines in the CSF of twin pairs discordant for schizophrenia or bipolar disorder and to study these CSF markers in relation to psychotic symptoms and personality traits. CSF levels of tryptophan (TRP), KYNA, quinolinic acid (QUIN), interleukin (IL)-6, IL-8 and tumor necrosis factor-alpha (TNF-α) were analyzed in 23 twins with schizophrenia or bipolar disorder, and in their not affected co-twins. Ratings of psychotic symptoms and personality traits were made using the Scales for Assessment of Negative and Positive symptoms, the Structured Clinical Interview for DSM-IV - Axis II Disorders, and the Schizotypal Personality Questionnaire - Brief. A total score for psychotic symptoms and personality traits was constructed for analysis. CSF KYNA was associated with the score for psychotic symptom and personality traits. TNF-α and IL-8 were associated, and the intra-pair differences scores of TNF-α and IL-8 were highly correlated. Intraclass correlations indicated genetic influences on CSF KYNA, TRP, IL-8 and TNF-α. The association between KYNA and psychotic symptoms further supports a role of KYNA in psychotic disorders.
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| 198. |
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| 199. |
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| 200. |
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