| 1. |
- Dinkler, Lisa, et al.
(författare)
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Maltreatment-associated neurodevelopmental disorders : a co-twin control analysis
- 2017
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Ingår i: Journal of Child Psychology and Psychiatry. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 0021-9630 .- 1469-7610.
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Childhood maltreatment (CM) is strongly associated with psychiatric disorders in childhood and adulthood. Previous findings suggest that the association between CM and psychiatric disorders is partly causal and partly due to familial confounding, but few studies have investigated the mechanisms behind the association between CM and neurodevelopmental disorders (NDDs). Our objective was to determine whether maltreated children have an elevated number of NDDs and whether CM is a risk factor for an increased NDD 'load' and increased NDD symptoms when controlling for familial effects. METHODS: We used a cross-sectional sample from a population-representative Swedish twin study, comprising 8,192 nine-year-old twins born in Sweden between 1997 and 2005. CM was defined as parent-reported exposure to emotional abuse/neglect, physical neglect, physical abuse, and/or sexual abuse. Four NDDs were measured with the Autism-Tics, AD/HD, and other comorbidities inventory. RESULTS: Maltreated children had a greater mean number of NDDs than nonmaltreated children. In a co-twin control design, CM-discordant monozygotic twins did not differ significantly for their number of NDDs, suggesting that CM is not associated with an increased load of NDDs when genetic and shared environmental factors are taken into account. However, CM was associated with a small increase in symptoms of attention-deficit/hyperactivity disorder and autism spectrum disorder in CM-discordant MZ twins, although most of the covariance of CM with NDD symptoms was explained by common genetic effects. CONCLUSIONS: Maltreated children are at higher risk of having multiple NDDs. Our findings are, however, not consistent with the notion that CM causes the increased NDD load in maltreated children. Maltreated children should receive a full neurodevelopmental assessment, and clinicians should be aware that children with multiple NDDs are at higher risk of maltreatment.
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| 2. |
- Lundström, Sebastian, et al.
(författare)
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Autism spectrum disorders and coexisting disorders in a nationwide Swedish twin study
- 2015
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Ingår i: Journal of Child Psychology and Psychiatry and Allied Disciplines. - Stockholm : Wiley. - 0021-9630 .- 1469-7610. ; 56:6, s. 702-710
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Tidskriftsartikel (refereegranskat)abstract
- Background: Evidence from twin and molecular genetic studies is accumulating that Autism Spectrum Disorder (ASD) shares substantial etiological factors with other disorders. This is mirrored in clinical practice where ASD without coexisting disorders is rare. The present study aims to examine the range of coexisting disorders in ASD in a genetically informative cohort. Methods: Parents of all Swedish 9-year-old twins born between 1992 and 2001 (n = 19,130) underwent a telephone interview designed to screen for child psychiatric disorders, including ASD. To ensure full coverage of child psychiatric disorders, data were also retrieved from population-based health registers. We investigated the coexistence of eight psychiatric disorders known to coexist with ASDs in probands and their co-twins. Results: Half of the individuals with ASDs (50.3%) had four or more coexisting disorders and only 4% did not have any concomitant disorder. The ‘healthy co-twin’ in ASD discordant monozygotic twin pairs was very often (79% of boys and 50% of girls) affected by at least one non-ASD disorder. The corresponding figures for ASD discordant dizygotic twin pairs were significantly lower (46% of males and 30% of females). Conclusions: Detailed phenotypic descriptions including symptoms of problems associated with a wide range of child psychiatric disorders may aid in unraveling the genetic architecture of ASD and should guide the development of intervention strategies addressing each problem type specifically.
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| 3. |
- Rydell, Mina, et al.
(författare)
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Has the attention deficit hyperactivity disorder phenotype become more common in children between 2004 and 2014? : Trends over 10 years from a Swedish general population sample
- 2018
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Ingår i: Journal of Child Psychology and Psychiatry. - Stockholm : Blackwell Publishing. - 0021-9630 .- 1469-7610. ; 59:8, s. 863-871
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Studies have reported increases in clinically diagnosed and treated attention deficit hyperactivity disorder (ADHD) during the last decade, but it is unclear if this reflects an increase in the underlying ADHD phenotype. We aimed to clarify if there has been an increase in the prevalence of ADHD-like traits in the general population from 2004 to 2014.METHOD: Data were collected from 9-year-old twins (19,271), participating in the population-based Child and Adolescent Twin Study in Sweden between 2004 and 2014. We assessed lifetime ADHD symptoms using the Autism-Tics, ADHD and other Comorbidities inventory. Research proxies for diagnostic-level ADHD and subthreshold ADHD were derived from this scale. We modeled the lifetime prevalence of diagnostic-level and subthreshold ADHD with logistic regression, and assessed mean ADHD scores each year with linear regression. Lifetime prevalence of clinically diagnosed ADHD was retrieved from the National Patient Register and modeled with logistic regression.RESULTS: The prevalence of diagnostic-level ADHD based on parent ratings did not differ significantly over time from 2004 to 2014 (OR 1.37; 95% CI: 0.77-2.45; p-value .233). Both subthreshold ADHD and mean ADHD scores increased significantly over time (both p-values <.001). Clinically diagnosed ADHD increased more than fivefold from 2004 to 2014 (OR 5.27, 95% CI: 1.85-14.96).CONCLUSIONS: We found no evidence of an increase in ADHD-like traits at the extreme end of the distribution from 2004 to 2014, but small increases in normal and subthreshold variations of ADHD-like traits were observed. This suggests that the increased rates of clinically diagnosed ADHD might reflect changes in diagnostic and treatment practices of ADHD, administrative changes in reporting diagnoses, greater awareness of ADHD, better access to healthcare, or current overdiagnosis, rather than an increase in the ADHD phenotype.
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| 4. |
- Lundström, Sebastian, et al.
(författare)
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Trajectories leading to autism spectrum disorders are affected by paternal age: findings from two nationally representative twin studies.
- 2010
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Ingår i: Journal of Child Psychology and Psychiatry, and Allied Disciplines. - : Wiley. - 0021-9630 .- 1469-7610. ; 51:7, s. 850-856
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Tidskriftsartikel (refereegranskat)abstract
- Background: Despite extensive efforts, the causes of autism remain unknown. Advancing paternal age has been associated with various neurodevelopmental disorders. We aim to investigate three unresolved questions: (a) What is the association between paternal age and autism spectrum disorders (ASD)?; (b) Does paternal age moderate the genetic and environmental etiological factors for ASD? (c) Does paternal age affect normal variation in autistic-like traits? Methods: Two nationally representative twin studies from Sweden (n = 11, 122, assessed at age 9 or 12) and the UK (n = 13, 524, assessed at age 9) were used. Categorical and continuous measures of ASD, autistic-like traits and autistic similarity were calculated and compared over paternal age categories. Results: Both cohorts showed a strong association between paternal age and the risk for ASD. A U-shaped risk association could be discerned since the offspring of both the youngest and oldest fathers showed an elevation in the risk for ASD. Autistic similarity increased with advancing paternal age in both monozygotic and dizygotic twins. Both cohorts showed significantly higher autistic-like traits in the offspring of the youngest and oldest fathers. Conclusions: Phenomena associated with paternal age are clearly involved in the trajectories leading to autistic-like traits and ASD. Mechanisms influencing the trajectories might differ between older and younger fathers. Molecular genetic studies are now needed in order to further understand the association between paternal age and ASD, as well as normal variation in social, language, and repetitive behaviors in the general population.
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| 5. |
- Arvidsson, Olof, et al.
(författare)
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Secular changes in the symptom level of clinically diagnosed autism.
- 2018
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Ingår i: Journal of child psychology and psychiatry, and allied disciplines. - : Wiley. - 1469-7610 .- 0021-9630. ; 59:7, s. 744-751
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Tidskriftsartikel (refereegranskat)abstract
- The prevalence of autism has been reported to have increased worldwide. A decrease over time in the number of autism symptoms required for a clinical autism diagnosis would partly help explain this increase. This study aimed to determine whether the symptom level of clinically diagnosed autism cases below age 13 had changed over time.Parents of Swedish 9-year old twins (n = 28,118) participated in a telephone survey, in which symptoms and dysfunction/suffering related to neurodevelopmental disorders [including autism, but also attention-deficit/hyperactivity disorder (ADHD), Developmental Coordination Disorder (DCD), and Learning Disabilities (LD)] in their children were assessed over a 10-year period. Survey data was merged with the National Patient Register containing clinically registered autism diagnoses (n = 271).In individuals who had been clinically diagnosed with autism before the age of 13, the symptom score for autism decreased on average 30% over more than a decade in birth cohorts 1992-2002. There was an average decrease of 50% in the autism symptom score from 2004 to 2014 in individuals who were diagnosed with autism at ages 7-12, but there was no decrease in those diagnosed at ages 0-6.Over time, considerably fewer autism symptoms seemed to be required for a clinical diagnosis of autism, at least for those diagnosed after the preschool years. The findings add support for the notion that the observed increase in autism diagnoses is, at least partly, the by-product of changes in clinical practice, and flag up the need for working in agreement with best practice guidelines.
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| 6. |
- Castellheim, Albert, et al.
(författare)
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The role of general anesthesia on traits of neurodevelopmental disorders in a Swedish cohort of twins.
- 2018
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Ingår i: Journal of child psychology and psychiatry, and allied disciplines. - : Wiley. - 1469-7610 .- 0021-9630. ; 59:9, s. 966-972
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Tidskriftsartikel (refereegranskat)abstract
- The role of general anesthetics as a risk factor for possible neurodevelopmental disorders (NDDs) in humans is unresolved. The investigation of the role of anesthetics in the development of postgeneral anesthesia (anesthesia onward) NDDs has proven to be complicated, partly because of the inherent confounding in clinical cohort studies, and partly by the fact that anesthetics are only one part in the complex process of anesthesia-surgery.Utilizing the Swedish databases Child and Adolescent Twins Study in Sweden (CATSS) and National Patient Register (NPR), we investigated twins discordant for anesthesia, born between 1997 and 2004 for traits of NDDs. We identified 68 twin pairs discordant for anesthesia and explored traits of Attention-Deficit/Hyperactivity Disorder (ADHD), Learning Disability (LD), and Autism Spectrum Disorder (ASD) in them while simultaneously taking congenital abnormalities and systemic disorders (CSDs) into account. We analyzed the possible effect of anesthesia on neurodevelopmental problems, and we analyzed the within-pair differences using conditional linear regression.Twins with a recorded episode of anesthesia had higher traits of NDDs than twins without; similarly twins with CSDs had higher mean scores on all traits than twins without CSDs. The within-pair analyses suggested that exposure to anesthesia was associated with higher scores of ADHD (regression coefficient 1.02 and 95% confidence intervals: 0.27-1.78) in monozygotic (MZ) twins discordant for anesthesia. This effect remained when adjusting for congenital abnormalities.Our finding that traits of ADHD were slightly associated with anesthesia in a genetically sensitive design is in need of replication and warrants further investigation. Future studies should aim to elucidate mechanisms behind this possible association (e.g. anesthetics doses, age at exposure, exposure duration).
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| 7. |
- Chen, C., et al.
(författare)
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Associations between psychiatric polygenic risk scores and general and specific psychopathology symptoms in childhood and adolescence between and within dizygotic twin pairs
- 2022
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Ingår i: Journal of Child Psychology and Psychiatry. - : Wiley. - 0021-9630 .- 1469-7610. ; 63:12, s. 1513-1522
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Tidskriftsartikel (refereegranskat)abstract
- Background Although polygenic risk scores (PRS) predict psychiatric problems, these associations might be attributable to indirect pathways including population stratification, assortative mating, or dynastic effects (mediation via parental environments). The goal of this study was to examine whether PRS-psychiatric symptom associations were attributable to indirect versus direct pathways. Methods The sample consisted of 3,907 dizygotic (DZ) twin pairs. In childhood, their parents rated them on 98 symptoms. In adolescence (n = 2,393 DZ pairs), both the parents and the twins rated themselves on 20 symptoms. We extracted one general and seven specific factors from the childhood data, and one general and three specific factors from the adolescent data. We then regressed each general factor model onto ten psychiatric PRS simultaneously. We first conducted the regressions between individuals (beta) and then within DZ twin pairs (beta(w)), which controls for indirect pathways. Results In childhood, the PRS for ADHD predicted general psychopathology (beta = 0.09, 95% CI: [0.06, 0.12]; beta(w) = 0.07 [0.01, 0.12]). Furthermore, the PRS for ADHD predicted specific inattention (beta = 0.04 [0.00, 0.08]; beta(w) = 0.09 [0.01, 0.17]) and specific hyperactivity (beta = 0.07 [0.04, 0.11]; beta(w) = 0.09 [0.01, 0.16]); the PRS for schizophrenia predicted specific learning (beta = 0.08 [0.03, 0.13]; beta(w) = 0.19 [0.08, 0.30]) and specific inattention problems (beta = 0.05 [0.01, 0.09]; beta(w) = 0.10 [0.02, 0.19]); and the PRS for neuroticism predicted specific anxiety (beta = 0.06 [0.02, 0.10]; beta(w) = 0.06 [0.00, 0.12]). Overall, the PRS-general factor associations were similar between individuals and within twin pairs, whereas the PRS-specific factors associations amplified by 84% within pairs. Conclusions This implies that PRS-psychiatric symptom associations did not appear attributable to indirect pathways such as population stratification, assortative mating, or mediation via parental environments. Rather, genetics appeared to directly influence symptomatology.
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| 8. |
- Dinkler, Lisa, et al.
(författare)
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Anorexia nervosa and autism: a prospective twin cohort study
- 2021
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Ingår i: Journal of Child Psychology and Psychiatry and Allied Disciplines. - : Wiley. - 0021-9630 .- 1469-7610. ; 62:3, s. 316-326
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Tidskriftsartikel (refereegranskat)abstract
- © 2020 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health. Background: Anorexia nervosa (AN) and autism spectrum disorder (ASD) may be phenotypically and etiologically linked. However, due to the absence of prospective studies, it remains unclear whether the elevation of autistic traits in AN is evident in early childhood. Here, we prospectively investigated autistic traits before and after the first diagnosis of AN. Methods: In a population-based sample of 5,987 individuals (52.4% female) from the Child and Adolescent Twin Study in Sweden, parents reported autistic traits at ages 9 and 18. AN and ASD diagnoses were retrieved from the Swedish National Patient Register. In addition, AN diagnoses were ascertained by parent-reported treatment for AN. We compared whether individuals with and without AN differed in autistic traits before the first diagnosis of AN (age 9) and after the first diagnosis of AN (age 18). Results: We did not find evidence for elevated autistic traits in 9-year-old children later diagnosed with AN. At age 18, however, there was a marked elevation in restricted/repetitive behavior and interests, but only in the subgroup of individuals with acute AN. A less pronounced elevation was observed for social communication problems. Conclusions: Coping strategies in individuals with ASD and the somewhat different female ASD phenotype may explain why we did not find elevated autistic traits in children who later developed AN. Alternatively, it is possible that elevated autistic traits were not present prior to the onset of AN, thus questioning the previously reported elevated prevalence of ASD in AN. Future studies should use tailored measurements in order to investigate whether autistic traits in individuals with AN are best conceptualized as an epiphenomenon of the acute AN phase or whether these symptoms indeed represent ASD as a clinically verifiable neurodevelopmental disorder.
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| 9. |
- Lichtenstein, P., et al.
(författare)
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Associations between conduct problems in childhood and adverse outcomes in emerging adulthood: a longitudinal Swedish nationwide twin cohort
- 2020
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Ingår i: Journal of Child Psychology and Psychiatry and Allied Disciplines. - : Wiley. - 0021-9630 .- 1469-7610. ; 61:7, s. 798-806
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Tidskriftsartikel (refereegranskat)abstract
- Background We examined whether childhood conduct problems predicted a wide range of adverse outcomes in emerging adulthood and whether the association with internalizing problems remained after adjusting for general comorbidity and externalizing problems. Methods Participants were 18,649 twins from the Child and Adolescent Twin Study in Sweden. At age 9/12, parents rated their children on eight conduct problems. Adverse outcomes were retrieved from national registers in emerging adulthood (median follow‐up time = 9.2 years), including diagnoses of six psychiatric disorders, prescriptions of antidepressants, suicide attempts, criminality, high school ineligibility, and social welfare recipiency. We estimated risk for the separate outcomes and examined if conduct problems predicted an internalizing factor above and beyond a general comorbidity and an externalizing factor. We used twin analyses to estimate genetic and environmental contributions to these associations. Results On the average, each additional conduct symptom in childhood was associated with a 32% increased risk of the adverse outcomes in emerging adulthood (mean hazard ratio = 1.32; range = 1.16, 1.56). A latent childhood conduct problems factor predicted the internalizing factor in emerging adulthood (βboys = .24, standard error, SE = 0.03; βgirls = .17, SE = 0.03), above and beyond its association with the externalizing (βboys = 0.21, SE = 0.04; βgirls = 0.17, SE = 0.05) and general factors (βboys = 0.45, SE = 0.03; βgirls = 0.34, SE = 0.04). These associations were differentially influenced by genetic and environmental factors. Conclusions It is important to monitor boys and girls with conduct problems not only for future externalizing problems, but also for future internalizing problems. Prevention of specific outcomes, however, might require interventions at different levels.
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| 10. |
- Lundström, Sebastian, et al.
(författare)
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Perceived child impairment and the 'autism epidemic'
- 2022
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Ingår i: Journal of Child Psychology and Psychiatry. - : Wiley. - 0021-9630 .- 1469-7610. ; 63:5, s. 591-598
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Tidskriftsartikel (refereegranskat)abstract
- Background The prevalence of diagnosed Autism Spectrum Disorder (ASD) has increased substantially across the world. Much - or even most - prevalence increase seems to reflect changes in diagnostic practice and ascertainment. A key part of ASD assessment is to document that the relevant symptoms are associated with clinical impairment. The aim of the present study is to capitalize on a nationwide longitudinal study spanning 15 consecutive birth year cohorts in order to investigate whether there has been a secular change in how parents perceive the impairment and suffering conferred by autism symptomatology in their children. Methods Data came from the Child and Adolescent Twin Study in Sweden (27,240 individuals), where parents had reported on their child's ASD symptoms and impairment. Impairment due to ASD symptoms was regressed on an ASD symptom score across time. This was done for five 3-year birth cohorts (1995-1997, 1998-2000, 2001-2003, 2004-2006, and 2007-2009). Results Reported impairment increased with consecutively later birth cohorts. This was evident across all levels of autism symptomatology. At clinically relevant levels of symptomatology, parents of those born 2007-2009 reported a 23% higher degree of impairment as compared with parents of those born in 1995-1997. The relative difference, however, was even greater at levels that previously would have been considered below the diagnostic threshold. Discussion The results presented here contribute to the notion of a growing diffuseness in the conceptualization of the ASD diagnosis by adding the element of secular changes in the parental perception of the consequences of ASD symptom expression.
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