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Auteur Alexandra HAVDAHL |
Documents disponibles écrits par cet auteur (5)
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Commentary: Meeting the challenge of multidimensionality in neurodevelopmental disorders-reflections on Johnson et al. (2021) / Laurie J. HANNIGAN in Journal of Child Psychology and Psychiatry, 62-5 (May 2021)
[article]
Titre : Commentary: Meeting the challenge of multidimensionality in neurodevelopmental disorders-reflections on Johnson et al. (2021) Type de document : Texte imprimé et/ou numérique Auteurs : Laurie J. HANNIGAN, Auteur ; Alexandra HAVDAHL, Auteur Article en page(s) : p.631-634 Langues : Anglais (eng) Index. décimale : PER Périodiques Résumé : Neurodevelopmental disorders are widely acknowledged to be complex and multifactorial in origin, but this is rarely reflected in the approaches used to study them. We reflect on the 2021 Annual Research review and its introduction of a new conceptual framework designed to make the complexity of early neurodevelopment more empirically tractable. We evaluate the review authors' justification, explanation, and guidance for implementation of their framework in the context of their stated goals and highlight key assumptions that support its conceptual validity. Finally, we offer a genetic epidemiological perspective on potential applications, suggesting ways in which genomic data can be used to elucidate causal mechanistic processes within the AMEND framework. En ligne : http://dx.doi.org/10.1111/jcpp.13416 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=445
in Journal of Child Psychology and Psychiatry > 62-5 (May 2021) . - p.631-634[article] Commentary: Meeting the challenge of multidimensionality in neurodevelopmental disorders-reflections on Johnson et al. (2021) [Texte imprimé et/ou numérique] / Laurie J. HANNIGAN, Auteur ; Alexandra HAVDAHL, Auteur . - p.631-634.
Langues : Anglais (eng)
in Journal of Child Psychology and Psychiatry > 62-5 (May 2021) . - p.631-634
Index. décimale : PER Périodiques Résumé : Neurodevelopmental disorders are widely acknowledged to be complex and multifactorial in origin, but this is rarely reflected in the approaches used to study them. We reflect on the 2021 Annual Research review and its introduction of a new conceptual framework designed to make the complexity of early neurodevelopment more empirically tractable. We evaluate the review authors' justification, explanation, and guidance for implementation of their framework in the context of their stated goals and highlight key assumptions that support its conceptual validity. Finally, we offer a genetic epidemiological perspective on potential applications, suggesting ways in which genomic data can be used to elucidate causal mechanistic processes within the AMEND framework. En ligne : http://dx.doi.org/10.1111/jcpp.13416 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=445 Early manifestations of genetic risk for neurodevelopmental disorders / Ragna Bugge ASKELAND in Journal of Child Psychology and Psychiatry, 63-7 (July 2022)
[article]
Titre : Early manifestations of genetic risk for neurodevelopmental disorders Type de document : Texte imprimé et/ou numérique Auteurs : Ragna Bugge ASKELAND, Auteur ; Laurie J. HANNIGAN, Auteur ; Helga ASK, Auteur ; Ziada AYORECH, Auteur ; Martin TESLI, Auteur ; Elizabeth CORFIELD, Auteur ; Per MAGNUS, Auteur ; Pål Rasmus NJØLSTAD, Auteur ; Ole A. ANDREASSEN, Auteur ; George DAVEY SMITH, Auteur ; Ted REICHBORN-KJENNERUD, Auteur ; Alexandra HAVDAHL, Auteur Article en page(s) : p.810-819 Langues : Anglais (eng) Mots-clés : Attention Deficit Disorder with Hyperactivity/complications/epidemiology/genetics Autism Spectrum Disorder/complications/epidemiology/genetics Child Child, Preschool Cohort Studies Female Humans Male Mothers Neurodevelopmental Disorders/complications/epidemiology/genetics Risk Factors Adhd MoBa Polygenic risk score autism hyperactivity inattention language and motor difficulties neurodevelopmental disorders repetitive behavior schizophrenia social communication Index. décimale : PER Périodiques Résumé : BACKGROUND: Attention deficit/hyperactivity disorder (ADHD), autism spectrum disorder (autism) and schizophrenia are highly heritable neurodevelopmental disorders, affecting the lives of many individuals. It is important to increase our understanding of how the polygenic risk for neurodevelopmental disorders manifests during childhood in boys and girls. METHODS: Polygenic risk scores (PRS) for ADHD, autism and schizophrenia were calculated in a subsample of 15?205 children from the Norwegian Mother, Father and Child Cohort Study (MoBa). Mother-reported traits of repetitive behavior, social communication, language and motor difficulties, hyperactivity and inattention were measured in children at 6 and 18?months, 3, 5 and 8?years. Linear regression models in a multigroup framework were used to investigate associations between the three PRS and dimensional trait measures in MoBa, using sex as a grouping variable. RESULTS: Before the age of 2, the ADHD PRS was robustly associated with hyperactivity and inattention, with increasing strength up to 8?years, and with language difficulties at age 5 and 8. The autism PRS was robustly associated with language difficulties at 18?months, motor difficulties at 36?months, and hyperactivity and inattention at 8?years. We did not identify robust associations for the schizophrenia PRS. In general, the PRS associations were similar in boys and girls. The association between ADHD PRS and hyperactivity at 18?months was, however, stronger in boys. CONCLUSIONS: Polygenic risk for autism and ADHD in the general population manifests early in childhood and broadly across behavioral measures of neurodevelopmental traits. En ligne : http://dx.doi.org/10.1111/jcpp.13528 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=477
in Journal of Child Psychology and Psychiatry > 63-7 (July 2022) . - p.810-819[article] Early manifestations of genetic risk for neurodevelopmental disorders [Texte imprimé et/ou numérique] / Ragna Bugge ASKELAND, Auteur ; Laurie J. HANNIGAN, Auteur ; Helga ASK, Auteur ; Ziada AYORECH, Auteur ; Martin TESLI, Auteur ; Elizabeth CORFIELD, Auteur ; Per MAGNUS, Auteur ; Pål Rasmus NJØLSTAD, Auteur ; Ole A. ANDREASSEN, Auteur ; George DAVEY SMITH, Auteur ; Ted REICHBORN-KJENNERUD, Auteur ; Alexandra HAVDAHL, Auteur . - p.810-819.
Langues : Anglais (eng)
in Journal of Child Psychology and Psychiatry > 63-7 (July 2022) . - p.810-819
Mots-clés : Attention Deficit Disorder with Hyperactivity/complications/epidemiology/genetics Autism Spectrum Disorder/complications/epidemiology/genetics Child Child, Preschool Cohort Studies Female Humans Male Mothers Neurodevelopmental Disorders/complications/epidemiology/genetics Risk Factors Adhd MoBa Polygenic risk score autism hyperactivity inattention language and motor difficulties neurodevelopmental disorders repetitive behavior schizophrenia social communication Index. décimale : PER Périodiques Résumé : BACKGROUND: Attention deficit/hyperactivity disorder (ADHD), autism spectrum disorder (autism) and schizophrenia are highly heritable neurodevelopmental disorders, affecting the lives of many individuals. It is important to increase our understanding of how the polygenic risk for neurodevelopmental disorders manifests during childhood in boys and girls. METHODS: Polygenic risk scores (PRS) for ADHD, autism and schizophrenia were calculated in a subsample of 15?205 children from the Norwegian Mother, Father and Child Cohort Study (MoBa). Mother-reported traits of repetitive behavior, social communication, language and motor difficulties, hyperactivity and inattention were measured in children at 6 and 18?months, 3, 5 and 8?years. Linear regression models in a multigroup framework were used to investigate associations between the three PRS and dimensional trait measures in MoBa, using sex as a grouping variable. RESULTS: Before the age of 2, the ADHD PRS was robustly associated with hyperactivity and inattention, with increasing strength up to 8?years, and with language difficulties at age 5 and 8. The autism PRS was robustly associated with language difficulties at 18?months, motor difficulties at 36?months, and hyperactivity and inattention at 8?years. We did not identify robust associations for the schizophrenia PRS. In general, the PRS associations were similar in boys and girls. The association between ADHD PRS and hyperactivity at 18?months was, however, stronger in boys. CONCLUSIONS: Polygenic risk for autism and ADHD in the general population manifests early in childhood and broadly across behavioral measures of neurodevelopmental traits. En ligne : http://dx.doi.org/10.1111/jcpp.13528 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=477 Maternal vitamin D during pregnancy and offspring autism and autism-associated traits: a prospective cohort study / Paul MADLEY-DOWD in Molecular Autism, 13 (2022)
[article]
Titre : Maternal vitamin D during pregnancy and offspring autism and autism-associated traits: a prospective cohort study Type de document : Texte imprimé et/ou numérique Auteurs : Paul MADLEY-DOWD, Auteur ; Christina DARDANI, Auteur ; Robyn E. WOOTTON, Auteur ; Kyle DACK, Auteur ; Tom PALMER, Auteur ; Rupert THURSTON, Auteur ; Alexandra HAVDAHL, Auteur ; Jean GOLDING, Auteur ; Deborah LAWLOR, Auteur ; Dheeraj RAI, Auteur Article en page(s) : 44 p. Langues : Anglais (eng) Mots-clés : Child Pregnancy Female Humans Autistic Disorder/epidemiology/etiology Longitudinal Studies Cohort Studies Prospective Studies Vitamin D Alspac Autism Mendelian randomization Index. décimale : PER Périodiques Résumé : BACKGROUND: There has been a growing interest in the association between maternal levels of vitamin D during pregnancy and offspring autism. However, whether any associations reflect causal effects is still inconclusive. METHODS: We used data from a UK-based pregnancy cohort study (Avon Longitudinal Study of Parents and Children) comprising 7689 births between 1991 and 1992 with maternal blood vitamin D levels recorded during pregnancy and at least one recorded outcome measure, including autism diagnosis and autism-associated traits. The association between each outcome with seasonal and gestational age-adjusted maternal serum 25-hydroxyvitamin D during pregnancy was estimated using confounder-adjusted regression models. Multiple imputation was used to account for missing data, and restricted cubic splines were used to investigate nonlinear associations. Mendelian randomization was used to strengthen causal inference. RESULTS: No strong evidence of an association between maternal serum 25-hydroxyvitamin D during pregnancy and any offspring autism-associated outcome was found using multivariable regression analysis (autism diagnosis: adjusted OR=0.98, 95% CI=0.90-1.06), including with multiple imputation (autism diagnosis: adjusted OR=0.99, 95% CI=0.93-1.06), and no evidence of a causal effect was suggested by Mendelian randomization (autism diagnosis: causal OR=1.08, 95% CI=0.46-2.55). Some evidence of increased odds of autism-associated traits at lower levels of maternal serum 25-hydroxyvitamin D was found using spline analysis. LIMITATIONS: Our study was potentially limited by low power, particularly for diagnosed autism cases as an outcome. The cohort may not have captured the extreme lows of the distribution of serum 25-hydroxyvitamin D, and our analyses may have been biased by residual confounding and missing data. CONCLUSIONS: The present study found no strong evidence of a causal link between maternal vitamin D levels in pregnancy and offspring diagnosis or traits of autism. En ligne : http://dx.doi.org/10.1186/s13229-022-00523-4 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=491
in Molecular Autism > 13 (2022) . - 44 p.[article] Maternal vitamin D during pregnancy and offspring autism and autism-associated traits: a prospective cohort study [Texte imprimé et/ou numérique] / Paul MADLEY-DOWD, Auteur ; Christina DARDANI, Auteur ; Robyn E. WOOTTON, Auteur ; Kyle DACK, Auteur ; Tom PALMER, Auteur ; Rupert THURSTON, Auteur ; Alexandra HAVDAHL, Auteur ; Jean GOLDING, Auteur ; Deborah LAWLOR, Auteur ; Dheeraj RAI, Auteur . - 44 p.
Langues : Anglais (eng)
in Molecular Autism > 13 (2022) . - 44 p.
Mots-clés : Child Pregnancy Female Humans Autistic Disorder/epidemiology/etiology Longitudinal Studies Cohort Studies Prospective Studies Vitamin D Alspac Autism Mendelian randomization Index. décimale : PER Périodiques Résumé : BACKGROUND: There has been a growing interest in the association between maternal levels of vitamin D during pregnancy and offspring autism. However, whether any associations reflect causal effects is still inconclusive. METHODS: We used data from a UK-based pregnancy cohort study (Avon Longitudinal Study of Parents and Children) comprising 7689 births between 1991 and 1992 with maternal blood vitamin D levels recorded during pregnancy and at least one recorded outcome measure, including autism diagnosis and autism-associated traits. The association between each outcome with seasonal and gestational age-adjusted maternal serum 25-hydroxyvitamin D during pregnancy was estimated using confounder-adjusted regression models. Multiple imputation was used to account for missing data, and restricted cubic splines were used to investigate nonlinear associations. Mendelian randomization was used to strengthen causal inference. RESULTS: No strong evidence of an association between maternal serum 25-hydroxyvitamin D during pregnancy and any offspring autism-associated outcome was found using multivariable regression analysis (autism diagnosis: adjusted OR=0.98, 95% CI=0.90-1.06), including with multiple imputation (autism diagnosis: adjusted OR=0.99, 95% CI=0.93-1.06), and no evidence of a causal effect was suggested by Mendelian randomization (autism diagnosis: causal OR=1.08, 95% CI=0.46-2.55). Some evidence of increased odds of autism-associated traits at lower levels of maternal serum 25-hydroxyvitamin D was found using spline analysis. LIMITATIONS: Our study was potentially limited by low power, particularly for diagnosed autism cases as an outcome. The cohort may not have captured the extreme lows of the distribution of serum 25-hydroxyvitamin D, and our analyses may have been biased by residual confounding and missing data. CONCLUSIONS: The present study found no strong evidence of a causal link between maternal vitamin D levels in pregnancy and offspring diagnosis or traits of autism. En ligne : http://dx.doi.org/10.1186/s13229-022-00523-4 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=491 Mechanisms linking parental educational attainment with child ADHD, depression, and academic problems: a study of extended families in The Norwegian Mother, Father and Child Cohort Study / Fartein Ask TORVIK in Journal of Child Psychology and Psychiatry, 61-9 (September 2020)
[article]
Titre : Mechanisms linking parental educational attainment with child ADHD, depression, and academic problems: a study of extended families in The Norwegian Mother, Father and Child Cohort Study Type de document : Texte imprimé et/ou numérique Auteurs : Fartein Ask TORVIK, Auteur ; Espen Moen EILERTSEN, Auteur ; Tom A. MCADAMS, Auteur ; Kristin GUSTAVSON, Auteur ; Henrik Daae ZACHRISSON, Auteur ; Ragnhild BRANDLISTUEN, Auteur ; Line C. GJERDE, Auteur ; Alexandra HAVDAHL, Auteur ; Camilla STOLTENBERG, Auteur ; Helga ASK, Auteur ; Eivind YSTROM, Auteur Article en page(s) : p.1009-1018 Langues : Anglais (eng) Mots-clés : Attention deficit hyperactivity disorder MoBa academic problems depression educational attainment Index. décimale : PER Périodiques Résumé : BACKGROUND: Low educational attainment in parents is associated with child psychopathology. It is not clear whether the associations are due to risk factors that family members share or due to effects of maternal or paternal education on the offspring. We investigate whether associations between maternal and paternal educational attainment and child symptoms of attention deficit/hyperactivity disorder (ADHD), depression, and academic problems are due to shared genetic factors, shared family environmental factors, or effects of the parental phenotype educational attainment itself. METHODS: This study is based on the Norwegian Mother, Father and Child Cohort Study (MoBa). The sample comprised 34,958 children (17,128 girls) in 28,372 extended-family units. We used data from related nuclear families linked by siblings in the parent generation. We applied a quasi-experimental extended children-of-twins design that included siblings in both generations and took account of nonrandom mating by including partners. Educational attainment was self-reported by mothers and fathers. Mothers reported children's symptoms of ADHD, symptoms of depression, and academic problems by questionnaire when the children were 8 years old. RESULTS: Children of lowly educated parents scored higher on all outcomes and had an approximate doubling of the risk of high symptom levels. The association between maternal and paternal educational attainment and child symptoms of ADHD and academic problems persisted after controlling for shared genetic and family environmental factors. Phenotypic transmission to depression was weaker and in the best fitting model fully explained by genetic factors shared by the two generations. CONCLUSIONS: Associations between educational attainment of mothers and fathers and child symptoms of ADHD and academic problems could not be ascribed to shared familial risk factors, whereas associations with symptoms of depression could. Parental education or resources and behaviors resulting from low education might be targets of interventions aimed at reducing symptoms of ADHD and academic problems. En ligne : http://dx.doi.org/10.1111/jcpp.13197 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=430
in Journal of Child Psychology and Psychiatry > 61-9 (September 2020) . - p.1009-1018[article] Mechanisms linking parental educational attainment with child ADHD, depression, and academic problems: a study of extended families in The Norwegian Mother, Father and Child Cohort Study [Texte imprimé et/ou numérique] / Fartein Ask TORVIK, Auteur ; Espen Moen EILERTSEN, Auteur ; Tom A. MCADAMS, Auteur ; Kristin GUSTAVSON, Auteur ; Henrik Daae ZACHRISSON, Auteur ; Ragnhild BRANDLISTUEN, Auteur ; Line C. GJERDE, Auteur ; Alexandra HAVDAHL, Auteur ; Camilla STOLTENBERG, Auteur ; Helga ASK, Auteur ; Eivind YSTROM, Auteur . - p.1009-1018.
Langues : Anglais (eng)
in Journal of Child Psychology and Psychiatry > 61-9 (September 2020) . - p.1009-1018
Mots-clés : Attention deficit hyperactivity disorder MoBa academic problems depression educational attainment Index. décimale : PER Périodiques Résumé : BACKGROUND: Low educational attainment in parents is associated with child psychopathology. It is not clear whether the associations are due to risk factors that family members share or due to effects of maternal or paternal education on the offspring. We investigate whether associations between maternal and paternal educational attainment and child symptoms of attention deficit/hyperactivity disorder (ADHD), depression, and academic problems are due to shared genetic factors, shared family environmental factors, or effects of the parental phenotype educational attainment itself. METHODS: This study is based on the Norwegian Mother, Father and Child Cohort Study (MoBa). The sample comprised 34,958 children (17,128 girls) in 28,372 extended-family units. We used data from related nuclear families linked by siblings in the parent generation. We applied a quasi-experimental extended children-of-twins design that included siblings in both generations and took account of nonrandom mating by including partners. Educational attainment was self-reported by mothers and fathers. Mothers reported children's symptoms of ADHD, symptoms of depression, and academic problems by questionnaire when the children were 8 years old. RESULTS: Children of lowly educated parents scored higher on all outcomes and had an approximate doubling of the risk of high symptom levels. The association between maternal and paternal educational attainment and child symptoms of ADHD and academic problems persisted after controlling for shared genetic and family environmental factors. Phenotypic transmission to depression was weaker and in the best fitting model fully explained by genetic factors shared by the two generations. CONCLUSIONS: Associations between educational attainment of mothers and fathers and child symptoms of ADHD and academic problems could not be ascribed to shared familial risk factors, whereas associations with symptoms of depression could. Parental education or resources and behaviors resulting from low education might be targets of interventions aimed at reducing symptoms of ADHD and academic problems. En ligne : http://dx.doi.org/10.1111/jcpp.13197 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=430 On the importance of parenting in externalizing disorders: an evaluation of indirect genetic effects in families / Espen M. EILERTSEN in Journal of Child Psychology and Psychiatry, 63-10 (October 2022)
[article]
Titre : On the importance of parenting in externalizing disorders: an evaluation of indirect genetic effects in families Type de document : Texte imprimé et/ou numérique Auteurs : Espen M. EILERTSEN, Auteur ; Rosa CHEESMAN, Auteur ; Ziada AYORECH, Auteur ; Espen RØYSAMB, Auteur ; Jean-Baptiste PINGAULT, Auteur ; Pål R. NJØLSTAD, Auteur ; Ole A. ANDREASSEN, Auteur ; Alexandra HAVDAHL, Auteur ; Tom A. MCADAMS, Auteur ; Fartein A. TORVIK, Auteur ; Eivind YSTRØM, Auteur Année de publication : 2022 Article en page(s) : p.1186-1195 Langues : Anglais (eng) Mots-clés : Child Cohort Studies Humans Parenting Parents Problem Behavior Externalizing disorders MoBa gene-environment correlation indirect genetic effects parenting Index. décimale : PER Périodiques Résumé : BACKGROUND: Theoretical models of the development of childhood externalizing disorders emphasize the role of parents. Empirical studies have not been able to identify specific aspects of parental behaviors explaining a considerable proportion of the observed individual differences in externalizing problems. The problem is complicated by the contribution of genetic factors to externalizing problems, as parents provide both genes and environments to their children. We studied the joint contributions of direct genetic effects of children and the indirect genetic effects of parents through the environment on externalizing problems. METHODS: The study used genome-wide single nucleotide polymorphism data from 9,675 parent-offspring trios participating in the Norwegian Mother Father and child cohort study. Based on genomic relatedness matrices, we estimated the contribution of direct genetic effects and indirect maternal and paternal genetic effects on ADHD, conduct and disruptive behaviors at 8years of age. RESULTS: Models including indirect parental genetic effects were preferred for the ADHD symptoms of inattention and hyperactivity, and conduct problems, but not oppositional defiant behaviors. Direct genetic effects accounted for 11% to 24% of the variance, whereas indirect parental genetic effects accounted for 0% to 16% in ADHD symptoms and conduct problems. The correlation between direct and indirect genetic effects, or gene-environment correlations, decreased the variance with 16% and 13% for conduct and inattention problems, and increased the variance with 6% for hyperactivity problems. CONCLUSIONS: This study provides empirical support to the notion that parents have a significant role in the development of childhood externalizing behaviors. The parental contribution to decrease in variation of inattention and conduct problems by gene-environment correlations would limit the number of children reaching clinical ranges in symptoms. Not accounting for indirect parental genetic effects can lead to both positive and negative bias when identifying genetic variants for childhood externalizing behaviors. En ligne : http://dx.doi.org/10.1111/jcpp.13654 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=486
in Journal of Child Psychology and Psychiatry > 63-10 (October 2022) . - p.1186-1195[article] On the importance of parenting in externalizing disorders: an evaluation of indirect genetic effects in families [Texte imprimé et/ou numérique] / Espen M. EILERTSEN, Auteur ; Rosa CHEESMAN, Auteur ; Ziada AYORECH, Auteur ; Espen RØYSAMB, Auteur ; Jean-Baptiste PINGAULT, Auteur ; Pål R. NJØLSTAD, Auteur ; Ole A. ANDREASSEN, Auteur ; Alexandra HAVDAHL, Auteur ; Tom A. MCADAMS, Auteur ; Fartein A. TORVIK, Auteur ; Eivind YSTRØM, Auteur . - 2022 . - p.1186-1195.
Langues : Anglais (eng)
in Journal of Child Psychology and Psychiatry > 63-10 (October 2022) . - p.1186-1195
Mots-clés : Child Cohort Studies Humans Parenting Parents Problem Behavior Externalizing disorders MoBa gene-environment correlation indirect genetic effects parenting Index. décimale : PER Périodiques Résumé : BACKGROUND: Theoretical models of the development of childhood externalizing disorders emphasize the role of parents. Empirical studies have not been able to identify specific aspects of parental behaviors explaining a considerable proportion of the observed individual differences in externalizing problems. The problem is complicated by the contribution of genetic factors to externalizing problems, as parents provide both genes and environments to their children. We studied the joint contributions of direct genetic effects of children and the indirect genetic effects of parents through the environment on externalizing problems. METHODS: The study used genome-wide single nucleotide polymorphism data from 9,675 parent-offspring trios participating in the Norwegian Mother Father and child cohort study. Based on genomic relatedness matrices, we estimated the contribution of direct genetic effects and indirect maternal and paternal genetic effects on ADHD, conduct and disruptive behaviors at 8years of age. RESULTS: Models including indirect parental genetic effects were preferred for the ADHD symptoms of inattention and hyperactivity, and conduct problems, but not oppositional defiant behaviors. Direct genetic effects accounted for 11% to 24% of the variance, whereas indirect parental genetic effects accounted for 0% to 16% in ADHD symptoms and conduct problems. The correlation between direct and indirect genetic effects, or gene-environment correlations, decreased the variance with 16% and 13% for conduct and inattention problems, and increased the variance with 6% for hyperactivity problems. CONCLUSIONS: This study provides empirical support to the notion that parents have a significant role in the development of childhood externalizing behaviors. The parental contribution to decrease in variation of inattention and conduct problems by gene-environment correlations would limit the number of children reaching clinical ranges in symptoms. Not accounting for indirect parental genetic effects can lead to both positive and negative bias when identifying genetic variants for childhood externalizing behaviors. En ligne : http://dx.doi.org/10.1111/jcpp.13654 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=486