| 1. |
- Brander, Gustaf, et al.
(författare)
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Association of Perinatal Risk Factors With Obsessive-Compulsive Disorder : A Population-Based Birth Cohort, Sibling Control Study
- 2016
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Ingår i: JAMA psychiatry. - Chicago, USA : American Medical Association. - 2168-6238 .- 2168-622X. ; 73:11, s. 1135-1144
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Tidskriftsartikel (refereegranskat)abstract
- Importance: Perinatal complications may increase the risk of obsessive-compulsive disorder (OCD). Previous reports were based on small, retrospective, specialist clinic-based studies that were unable to rigorously control for unmeasured environmental and genetic confounding.Objective: To prospectively investigate a wide range of potential perinatal risk factors for OCD, controlling for unmeasured factors shared between siblings in the analyses.Design, Setting, and Participants: This population-based birth cohort study included all 2 421 284 children from singleton births in Sweden from January 1, 1973, to December 31, 1996, who were followed up through December 31, 2013. From the 1 403 651 families in the cohort, differentially exposed siblings from the 743 885 families with siblings were evaluated; of these, 11 592 families included clusters of full siblings that were discordant for OCD. Analysis of the data was conducted from January, 26, 2015, to September, 5, 2016.Exposures: Perinatal data were collected from the Swedish Medical Birth Register and included maternal smoking during pregnancy, labor presentation, obstetric delivery, gestational age (for preterm birth), birth weight, birth weight in relation to gestational age, 5-minute Apgar score, and head circumference.Main Outcomes and Measures: Previously validated OCD codes (International Statistical Classification of Diseases and Health Related Problems, Tenth Revision, code F42) in the Swedish National Patient Register.Results: Of 2 421 284 individuals included in the cohort, 17 305 persons were diagnosed with OCD. Of these, 7111 were men (41.1%). The mean (SD) age of individuals at first diagnosis of OCD was 23.4 (6.5) years. An increased risk for OCD remained after controlling for shared familial confounders and measured covariates (including sex, year of birth, maternal and paternal age at birth, and parity), for smoking 10 or more cigarettes per day during pregnancy (hazard ratio [HR], 1.27; 95% CI, 1.02-1.58), breech presentation (HR, 1.35; 95% CI, 1.06-1.71), delivery by cesarean section (HR, 1.17; 95% CI, 1.01-1.34), preterm birth (HR, 1.24; 95% CI, 1.07-1.43), birth weight 1501 to 2500 g (HR, 1.30; 95% CI, 1.05-1.62) and 2501 to 3500 g (HR, 1.08; 95% CI, 1.01-1.16), being large for gestational age (HR, 1.23; 95% CI, 1.05-1.45), and Apgar distress scores at 5 minutes (HR, 1.50; 95% CI, 1.07-2.09). Gestational age and birth weight followed inverse dose-response associations, whereby an increasingly higher risk for OCD was noted in children with a shorter gestational age and lower birth weight. We also observed a dose-response association between the number of perinatal events and increased OCD risk, with HRs ranging from 1.11 (95% CI, 1.07-1.15) for 1 event to 1.51 (95% CI, 1.18-1.94) for 5 or more events.Conclusions and Relevance: A range of perinatal risk factors is associated with a higher risk for OCD independent of shared familial confounders, suggesting that perinatal risk factors may be in the causal pathway to OCD.
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| 2. |
- Brikell, Isabell, et al.
(författare)
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Relative Immaturity in Childhood and Attention-Deficit/Hyperactivity Disorder Symptoms From Childhood to Early Adulthood : Exploring Genetic and Environmental Overlap Across Development
- 2016
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Ingår i: Journal of the American Academy of Child and Adolescent Psychiatry. - : Elsevier. - 0890-8567 .- 1527-5418. ; 55:10, s. 886-895
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Attention-deficit/hyperactivity disorder (ADHD) has been linked to immaturity relative to peers in childhood, yet it is unclear how such immaturity is associated with ADHD across development. This longitudinal twin study examined the genetic and environmental contributions to the association between parents' perception of their child's immaturity relative to peers (RI) in childhood and ADHD symptoms across development.Method: 1,302 twin pairs from the Swedish Twin Study of Child and Adolescent Development were followed prospectively from childhood to early adulthood. Parent ratings of RI were collected at 8 to 9 years and parent and self-ratings of ADHD symptoms were collected at 8 to 9, 13 to 14, 16 to 17, and 19 to 20 years using the Child Behavior Checklist Attention Problems scale. In addition, ADHD symptoms corresponding to DSM criteria were used for sensitivity analysis. Analyses were conducted using longitudinal structural equation modeling with multiple raters.Results: RI-related etiologic factors, predominantly influenced by genes, explained 10-14% of the variance in ADHD symptoms from 8 to 9 up to 16 to 17 years. The influence of these RI-related factors on ADHD symptoms attenuated to 4% by 19 to 20 years of age. The remaining variance in ADHD symptoms was primarily explained by genetic factors independent of RI, which remained relatively stable across development, explaining 19% to 30% of the variance in ADHD symptoms from 13 to 14 up to 19 to 20 years.Conclusion: The results show that RI is significantly associated with ADHD symptoms, particularly during childhood and adolescence, and that the association is primarily explained by a shared genetic liability. Nevertheless, the magnitude of associations across development was modest, highlighting that RI is merely one aspect contributing to the complex etiology of ADHD symptoms.
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| 3. |
- D'Onofrio, Brian M., et al.
(författare)
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Translational Epidemiologic Approaches to Understanding the Consequences of Early-Life Exposures
- 2016
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Ingår i: Behavior Genetics. - New York, USA : Springer. - 0001-8244 .- 1573-3297. ; 46:3, s. 315-328
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Forskningsöversikt (refereegranskat)abstract
- Prominent developmental theories posit a causal link between early-life exposures and later functioning. Yet, observed associations with early exposures may not reflect causal effects because of genetic and environmental confounding. The current manuscript describes how a systematic series of epidemiologic analyses that combine several genetically-informative designs and statistical approaches can help distinguish between competing theories. In particular, the manuscript details how combining the use of measured covariates with sibling-comparisons, cousin-comparisons, and additional designs can help elucidate the sources of covariation between early-life exposures and later outcomes, including the roles of (a) factors that are not shared in families, including a potential causal effect of the exposure; (b) carryover effects from the exposure of one child to the next; and (c) familial confounding. We also describe key assumptions and how they can be critically evaluated. Furthermore, we outline how subsequent analyses, including effect decomposition with respect to measured, plausible mediators, and quantitative genetic models can help further specify the underlying processes that account for the associations between early-life exposures and offspring outcomes.
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| 4. |
- Kuja-Halkola, Ralf, et al.
(författare)
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Heritability of non-HLA genetics in coeliac disease : a population-based study in 107 000 twins
- 2016
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Ingår i: Gut. - London, United Kingdom : BMJ Publishing Group Ltd. - 0017-5749 .- 1468-3288. ; 65:11, s. 1793-1798
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Tidskriftsartikel (refereegranskat)abstract
- Background and objective: Almost 100% individuals with coeliac disease (CD) are carriers of the human leucocyte antigen (HLA) DQ2/DQ8 alleles. Earlier studies have, however, failed to consider the HLA system when estimating heritability in CD, thus violating an underlying assumption of heritability analysis. We examined the heritability of CD in a large population-based sample of twins, considering HLA.Design: In a population-representative sample of 107 912 twins, we identified individuals with CD (equal to villous atrophy) through biopsy reports from all Swedish pathology departments. We calculated concordance rates and tetrachoric correlations for monozygotic (MZ) and dizygotic (DZ) twin pairs. Further, we estimated heritability of CD, first strictly from observed data, and then the non-HLA heritability, representing the heritability of all genetic factors except the HLA locus, using an approach that circumvent the violation of underlying assumptions.Results: We identified 513 twins with a diagnosis of CD (prevalence 0.48%). Concordance rates were higher in MZ pairs (0.49) than in DZ pairs (0.10), as were tetrachoric correlations (0.89 in MZ vs 0.51 in DZ pairs). The heritability of CD was 75% (95% CI 55% to 96%). The non-HLA heritability was slightly attenuated, 68% (95% CI 40% to 96%), with shared (17%) and non-shared (15%) environmental factors explaining the remaining variability of CD.Conclusions: CD is characterised by a high heritability, but our study also suggests that non-shared environmental factors may be of importance to CD development. HLA seems to have only moderate impact on heritability estimates.
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| 5. |
- Latvala, Antti, et al.
(författare)
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Association of Resting Heart Rate and Blood Pressure in Late Adolescence With Subsequent Mental Disorders : A Longitudinal Population Study of More Than 1 Million Men in Sweden
- 2016
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Ingår i: JAMA psychiatry. - Chicago, USA : American Medical Association. - 2168-6238 .- 2168-622X. ; 73:12, s. 1268-1275
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Tidskriftsartikel (refereegranskat)abstract
- Importance: Differences in cardiovascular autonomic activity between individuals with psychiatric disorders and healthy controls have been observed, but whether cardiovascular autonomic abnormalities are associated with subsequent psychiatric disorders is unknown.Objective: To investigate whether differences in cardiac autonomic function as indexed by resting heart rate and blood pressure are associated with psychiatric disorders during the lifetime of men in Sweden.Design, Setting, and Participants: We conducted a longitudinal register-based study of Swedish men whose resting heart rate (n = 1 039 443) and blood pressure (n = 1 555 979) were measured at military conscription at a mean (SD) age of 18.3 (0.6) years during the period from 1969 to 2010, with register-based follow-up data available until the end of 2013. Analyses were performed from November 18, 2015, to June 9, 2016.Main Outcomes and Measures: Dates of inpatient/outpatient diagnoses of anxiety disorders, obsessive-compulsive disorder, posttraumatic stress disorder, depressive disorders, bipolar disorder, schizophrenia, and substance use disorders and convictions for violent crimes, between 1973 and 2013, were obtained from nationwide registers. Adjustments were made for height, weight, body mass index, cardiorespiratory fitness, cognitive ability, and socioeconomic covariates.Results: After adjustment for covariates, Cox regression models with up to 45 years of follow-up data showed that men (mean [SD] age of 18.3 [0.6] years at conscription) with resting heart rates above 82 beats per minute had a 69% (95% CI, 46%-94%) increased risk for obsessive-compulsive disorder, a 21% (95% CI, 11%-33%) increased risk for schizophrenia, and an 18% (95% CI, 13%-22%) increased risk for anxiety disorders compared with men with resting heart rates below 62 beats per minute. Similar associations were observed with systolic/diastolic blood pressure. In contrast, lower resting heart rate and lower systolic blood pressure were associated with substance use disorders and violent criminality.Conclusions and Relevance: Our results suggest that for men, differences in heart rate and blood pressure in late adolescence are associated with lifetime major psychiatric disorders, with higher levels associated with obsessive-compulsive disorder, schizophrenia, and anxiety disorders and lower levels associated with substance use disorders and violent behavior. Differences in autonomic nervous system functioning may predate or represent an early marker of psychiatric disorders.
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| 6. |
- Latvala, Antti, et al.
(författare)
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Cognitive ability and risk for substance misuse in men : genetic and environmental correlations in a longitudinal nation-wide family study
- 2016
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Ingår i: Addiction. - Stockholm : Wiley-Blackwell Publishing Inc.. - 0965-2140 .- 1360-0443. ; 111:10, s. 1814-1822
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To investigate the association in males between cognitive ability in late adolescence and subsequent substance misuse-related events, and to study the underlying genetic and environmental correlations.Design: A population-based longitudinal study with three different family-based designs. Cox proportional hazards models were conducted to investigate the association at the individual level. Bivariate quantitative genetic modelling in (1) full brothers and maternal half-brothers, (2) full brothers reared together and apart and (3) monozygotic and dizygotic twin brothers was used to estimate genetic and environmental correlations.Setting: Register-based study in Sweden.Participants: The full sample included 1 402 333 Swedish men born 1958-91 and conscripted at mean age 18.2 [standard deviation (SD) = 0.5] years. A total of 1 361 066 men who had no substance misuse events before cognitive assessment at mandatory military conscription were included in the Cox regression models, with a follow-up time of up to 35.6 years.Measures Cognitive ability was assessed at conscription with the Swedish Enlistment Battery. Substance misuse events included alcohol- and drug-related court convictions, medical treatments and deaths, available from governmental registries.Findings: Lower cognitive ability in late adolescence predicted an increased risk for substance misuse events [hazard ratio (HR) for a 1-stanine unit decrease in cognitive ability: 1.29, 95% confidence interval (CI) = 1.29-1.30]. The association was somewhat attenuated within clusters of full brothers (HR = 1.21, 95% CI = 1.20-1.23). Quantitative genetic analyses indicated that the association was due primarily to genetic influences; the genetic correlations ranged between -0.39 (95% CI = -0.45, -0.34) and -0.52 (95% CI -0.55, -0.48) in the three different designs.Conclusions: Shared genetic influences appear to underlie the association between low cognitive ability and subsequent risk for substance misuse events among Swedish men.
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| 7. |
- Viktorin, Alexander, et al.
(författare)
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Heritability of perinatal depression and genetic overlap with nonperinatal depression
- 2016
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Ingår i: The American Journal of Psychiatry. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 0002-953X .- 1535-7228.
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The authors investigated the relative importance of genetic and environmental influences on perinatal depression, and the genetic overlap between perinatal depression and nonperinatal depression. METHOD: Analyses were conducted using structural equation modeling for 1) the lifetime version of the Edinburgh Postnatal Depression Scale in 3,427 Swedish female twins and 2) clinical diagnoses of depression separated into perinatal depression and nonperinatal depression in a Swedish population-based cohort of 580,006 sisters. RESULTS: In the twin study, the heritability of perinatal depression was estimated at 54% (95% CI=35%-70%), with the remaining variance attributable to nonshared environment (46%; 95% CI=31%-65%). In the sibling design, the heritability of perinatal depression was estimated at 44% (95% CI=35%-52%) and the heritability of nonperinatal depression at 32% (95% CI=24%-41%). Bivariate analysis showed that 14% of the total variance (or 33% of the genetic variance) in perinatal depression was unique for perinatal depression. CONCLUSIONS: The heritability of perinatal depression was estimated at 54% and 44%, respectively, in separate samples, and the heritability of nonperinatal depression at 32%. One-third of the genetic contribution was unique to perinatal depression and not shared with nonperinatal depression, suggesting only partially overlapping genetic etiologies for perinatal depression and nonperinatal depression. The authors suggest that perinatal depression constitutes a subset of depression that could be prioritized for genomic discovery efforts. The study findings have direct translational impact that can assist clinicians in the counseling of their patients regarding risk and prognosis of perinatal depression.
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