| 1. |
- 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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| 2. |
- Hou, Liping, et al.
(författare)
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Genome-wide association study of 40,000 individuals identifies two novel loci associated with bipolar disorder.
- 2016
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Ingår i: Human molecular genetics. - : Oxford University Press (OUP). - 1460-2083 .- 0964-6906. ; 25:15, s. 3383-94
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Tidskriftsartikel (refereegranskat)abstract
- Bipolar disorder (BD) is a genetically complex mental illness characterized by severe oscillations of mood and behavior. Genome-wide association studies (GWAS) have identified several risk loci that together account for a small portion of the heritability. To identify additional risk loci, we performed a two-stage meta-analysis of >9 million genetic variants in 9,784 bipolar disorder patients and 30,471 controls, the largest GWAS of BD to date. In this study, to increase power we used ∼2,000 lithium-treated cases with a long-term diagnosis of BD from the Consortium on Lithium Genetics, excess controls, and analytic methods optimized for markers on the X-chromosome. In addition to four known loci, results revealed genome-wide significant associations at two novel loci: an intergenic region on 9p21.3 (rs12553324, p = 5.87 × 10(-9); odds ratio = 1.12) and markers within ERBB2 (rs2517959, p = 4.53 × 10(-9); odds ratio = 1.13). No significant X-chromosome associations were detected and X-linked markers explained very little BD heritability. The results add to a growing list of common autosomal variants involved in BD and illustrate the power of comparing well-characterized cases to an excess of controls in GWAS.
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| 3. |
- Hughes, Timothy, et al.
(författare)
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A Loss-of-Function Variant in a Minor Isoform of ANK3 Protects Against Bipolar Disorder and Schizophrenia.
- 2016
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Ingår i: Biological psychiatry. - : Elsevier BV. - 1873-2402 .- 0006-3223. ; 80:4
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Tidskriftsartikel (refereegranskat)abstract
- Ankyrin-3 (ANK3) was one of the first genes to reach significance in a bipolar disorder genome-wide association study. Many subsequent association studies confirmed this finding and implicated this gene in schizophrenia. However, the exact nature of the role of ANK3 in the pathophysiology remains elusive. In particular, the specific isoforms involved and the nature of the imbalance are unknown.
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| 4. |
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| 5. |
- Lu, Donghao, et al.
(författare)
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A shared genetic contribution to breast cancer and schizophrenia.
- 2020
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- An association between schizophrenia and subsequent breast cancer has been suggested; however the risk of schizophrenia following a breast cancer is unknown. Moreover, the driving forces of the link are largely unclear. Here, we report the phenotypic and genetic positive associations of schizophrenia with breast cancer and vice versa, based on a Swedish population-based cohort and GWAS data from international consortia. We observe a genetic correlation of 0.14 (95% CI 0.09-0.19) and identify a shared locus at 19p13 (GATAD2A) associated with risks of breast cancer and schizophrenia. The epidemiological bidirectional association between breast cancer and schizophrenia may partly be explained by the genetic overlap between the two phenotypes and, hence, shared biological mechanisms.
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| 6. |
- Smedler, Erik, et al.
(författare)
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Genes, biomarkers, and clinical features associated with the course of bipolar disorder.
- 2019
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Ingår i: European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology. - : Elsevier BV. - 1873-7862. ; 29:10, s. 1152-1160
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Tidskriftsartikel (refereegranskat)abstract
- There is considerable variability in the severity of bipolar disorder, e.g., in terms of the frequency of inpatient episodes. The long-term progression also differs, where some patients are sensitised with progressively shorter healthy intervals. Little is known about the proportion of patients being sensitised, their clinical characteristics, and biological underpinnings. We analysed long-term progression of bipolar disorder in relation to clinical characteristics (N = 3074), serum biomarkers (N = 745), and genetic variants (N = 1401) in a cohort of Swedish bipolar disorder patients. We took advantage of the National Patient Register, providing reliable data on 35,973 psychiatric inpatient care episodes in Sweden since 1973. First, one third of the cohort cluster together with a maximum of one inpatient episode per year, while the remaining two thirds had >1 episode per year. These groups did not differ with respect to clinical features or biomarkers. Second, among patients with at least five inpatient episodes (defined as severely ill), we find one group with progressively shorter cycle-lengths (one fifth of the total cohort, N = 550). Compared with those with a stable or recuperant trajectory, these patients featured lower functioning, more antidepressant treatment, as well as reduced levels of inflammatory markers in serum. Third, sensitisation was associated with a common genetic variant near the calcium channel gene CACNA2D3 at genome-wide significance. These results suggest the potential for translational research aimed at preventive actions.
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| 7. |
- Song, Jie, et al.
(författare)
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Bipolar disorder and its relation to major psychiatric disorders : a family-based study in the Swedish population
- 2015
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Ingår i: Bipolar Disorders. - Stockholm : Wiley-Blackwell. - 1398-5647 .- 1399-5618. ; 17:2, s. 184-193
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Bipolar disorder (BPD) shares genetic components with other psychiatric disorders; however, uncertainty remains about where in the psychiatric spectra BPD falls. To understand the etiology of BPD, we studied the familial aggregation of BPD and co-aggregation between BPD and schizophrenia, depression, anxiety disorders, attention-deficit hyperactivity disorder, drug abuse, personality disorders, and autism spectrum disorders.METHODS: A population-based cohort was created by linking several Swedish national registers. A total of 54,723 individuals with BPD were identified among 8,141,033 offspring from 4,149,748 nuclear families. The relative risk of BPD in relatives and the co-occurrence of other psychiatric disorders in patients with BPD and their relatives were compared to those of matched-population controls. Structural equation modeling was used to estimate the heritability and tetrachoric correlation.RESULTS: The familial risks for relatives of BPD probands were 5.8-7.9 in first-degree relatives, and decreased with genetic distance. Co-occurrence risks for other psychiatric disorders were 9.7-22.9 in individuals with BPD and 1.7-2.8 in full siblings of BPD probands. Heritability for BPD was estimated at 58%. The correlations between BPD and other psychiatric disorders were considerable (0.37-0.62) and primarily due to genetic effects. The correlation with depression was the highest (0.62), and was 0.44 for schizophrenia.CONCLUSIONS: The high familial risks provide evidence that genetic factors play an important role in the etiology of BPD, and the shared genetic determinants suggest pleiotropic effects across different psychiatric disorders. Results also indicate that BPD is in both the mood and psychotic spectra, but possibly more closely related to mood disorders.
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| 8. |
- Song, Jie, et al.
(författare)
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Key subphenotypes of bipolar disorder are differentially associated with polygenic liabilities for bipolar disorder, schizophrenia, and major depressive disorder
- 2024
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Ingår i: MOLECULAR PSYCHIATRY. - 1359-4184 .- 1476-5578.
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Tidskriftsartikel (refereegranskat)abstract
- Bipolar disorder (BD) features heterogenous clinical presentation and course of illness. It remains unclear how subphenotypes associate with genetic loadings of BD and related psychiatric disorders. We investigated associations between the subphenotypes and polygenic risk scores (PRS) for BD, schizophrenia, and major depressive disorder (MDD) in two BD cohorts from Sweden (N = 5180) and the UK (N = 2577). Participants were assessed through interviews and medical records for inter-episode remission, psychotic features during mood episodes, global assessment of functioning (GAF, function and symptom burden dimensions), and comorbid anxiety disorders. Meta-analyses based on both cohorts showed that inter-episode remission and GAF-function were positively correlated with BD-PRS but negatively correlated with schizophrenia-PRS (SCZ-PRS) and MDD-PRS. Moreover, BD-PRS was negatively, and MDD-PRS positively, associated with the risk of comorbid anxiety disorders. Finally, SCZ-PRS was positively associated with psychotic symptoms during mood episodes. Assuming a higher PRS of certain psychiatric disorders in cases with a positive family history, we further tested the associations between subphenotypes in index BD people and occurrence of BD, schizophrenia, or MDD in their relatives using Swedish national registries. BD patients with a relative diagnosed with BD had: (1) higher GAF and lower risk of comorbid anxiety than those with a relative diagnosed with schizophrenia or MDD, (2) lower risk of psychotic symptoms than those with a relative diagnosed with schizophrenia. Our findings shed light on the genetic underpinnings of the heterogeneity in clinical manifestations and course of illness in BD, which ultimately provide insights for developing personalized approaches to the diagnosis and treatment.
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| 9. |
- Song, Jie, et al.
(författare)
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Specificity in Etiology of Subtypes of Bipolar Disorder : Evidence From a Swedish Population-Based Family Study
- 2018
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Ingår i: Biological Psychiatry. - : Elsevier. - 0006-3223 .- 1873-2402. ; 84:11, s. 810-816
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Tidskriftsartikel (refereegranskat)abstract
- Background: Uncertainty remains whether bipolar I disorder (BDI) and bipolar II disorder (BDII) differ etiologically. We used a population-based family sample to examine the etiological boundaries between BDI and BDII by assessing their familial aggregation/coaggregation and by assessing the coaggregation between them and schizophrenia, depression, attention-deficit/hyperactivity disorder, eating disorders, autism spectrum disorder, substance use disorders, anxiety disorders, and personality disorders.Methods: By linking Swedish national registers, we established a population-based cohort (N = 15,685,511) and identified relatives with different biological relationships. Odds ratios (ORs) were used to measure the relative risk of BDI and BDII in relatives of individuals diagnosed with BDI (n = 4309) and BDII (n = 4178). The heritability for BDI and BDII and the genetic correlation across psychiatric disorders were estimated by variance decomposition analysis.Results: Compared with the general population, the OR of BDI was 17.0 (95% confidence interval [CI] 13.1-22.0) in first-degree relatives of BDI patients, higher than that of BDII patients (OR 9.8, 95% CI 7.7-12.5). The ORs of BDII were 13.6 (95% CI 10.2-18.2) in first-degree relatives of BDII patients and 9.8 (95% CI 7.7-12.4) in relatives of BDI patients. The heritabilities for BDI and BDII were estimated at 57% (95% CI 32%-79%) and 46% (95% CI 21%-67%), respectively, with a genetic correlation estimated as 0.78 (95% CI 0.36-1.00). The familial coaggregation of other psychiatric disorders, in particular schizophrenia, showed different patterns for BDI and BDII.Conclusions: Our results suggest a distinction between BDI and BDII in etiology, partly due to genetic differences.
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| 10. |
- Song, Jie, et al.
(författare)
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Suicidal Behavior During Lithium and Valproate Treatment : A Within-Individual 8-Year Prospective Study of 50,000 Patients With Bipolar Disorder
- 2017
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Ingår i: American Journal of Psychiatry. - : American Psychiatric Association. - 0002-953X .- 1535-7228. ; 174:8, s. 795-802
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Conclusions regarding lithium's antisuicidal effect for bipolar disorder have been limited due to nonrepresentative subjects and potential confounding factors, including varying severity of illness. Findings regarding the effect of valproate, the most common alternative to lithium, are inconsistent for suicidal behavior. This study investigated the associations of these two drugs with the risk of suicide-related events, and possible differences between drugs, by using within-individual designs in a register-based longitudinal cohort.Method: Through linkage of multiple Swedish national registers, 51,535 individuals with bipolar disorder were followed from 2005 to 2013 for treatment with lithium and valproate. Stratified Cox regression was used to estimate the hazard ratios of suicide-related events during treated periods compared with untreated periods. For significant associations between medication and suicide-related events, the population attributable fraction was estimated to assess the public health impact for patients with bipolar disorder.Results: During follow-up, 10,648 suicide-related events occurred. The incidence rate was significantly decreased by 14% during lithium treatment (hazard ratio 0.86, 95% confidence interval [CI] 0.78-0.95) but not during valproate treatment (hazard ratio 1.02, 95% CI 0.89-1.15). The difference in hazard ratios of suicide-related events between lithium and valproate was statistically significant. Estimates of the population attributable fraction suggested that 12% (95% CI 4% 220%) of suicide-related events could have been avoided if patients had taken lithium during the entire follow-up.Conclusions: The results suggest that lithium should be considered for patients with bipolar disorder with suspected suicidal intentions, although risk for suicide is only one of the considerations when providing clinical care.
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