Intergenerational Transmission of Parental Neuroticism to Emotional Problems in 8-Year Old Children: Genetic and Environmental Mechanisms

Abstract

Background: Children of parents with high levels of neuroticism tend to have high neuroticism themselves, as well as increased risk of experiencing symptoms of anxiety and depression. It is not yet clear how much of this link is attributable to a potential effect of parent on child (e.g., via a socializing effect) vs. to shared genetic risk. Methods: This study is based on data from the Norwegian Mother, Father and Child Cohort Study. We used data from 11,088 sibling pairs in the parental generation, their partners (N= 22,176), and their offspring (N=26,091). Exposures were maternal and paternal neuroticism (self-reported), and the outcomes were neuroticism, symptoms of depression, and symptoms of anxiety in 8-year-old children (mother-reported). Outcomes: After accounting for assortative mating in parents (phenotypic r=0.26), genetic transmission of maternal neuroticism accounted for 16% of the correlation with offspring neuroticism (mother-child r=0.31), 18% of the association with offspring depressive symptoms (r=0.31), and 0% of the association with offspring anxiety symptoms (r=0.16). Intergenerational transmission of genes associated with paternal neuroticism accounted for ~40% of the father-offspring correlations with neuroticism and symptoms of depression (r=0.13 and 0.13, respectively) but none with offspring symptoms of anxiety (r=0.05). The remaining father-offspring correlations was explained by maternal influences through assortative mating. Interpretations: These results are consistent with direct effects between maternal and offspring neuroticism and between maternal neuroticism and offspring symptoms of anxiety and depression, suggesting that interventions targeted at family functioning could benefit the children. Funding Statement: This work was supported by the Research Council of Norway (RCN) (262177). E.M.E. and L.C.G. were funded by the RCN (262177). E.Y. was funded by the RCN (288083 and 262177). A.H. was supported by the South-Eastern Norway Regional Health Authority (2018059 and 2020022). T.A.McA. was supported by a Sir Henry Dale Fellowship, jointly funded by the Wellcome Trust and the Royal Society (107706/Z/15/Z) and the RCN (288083). L.J.H. was supported by funding from the SouthEastern Norway Regional Health Authority (2018058). F.A.T. was supported by the RCN (300668). This work was partly supported by the RCN through its Centres of Excellence funding scheme, project number 262700. Declaration of Interests: The authors have declared that they have no competing or potential conflicts of interest. Ethics Approval Statement: The establishment of MoBa and initial data collection was based on a license from the Norwegian Data protection agency and approval from The Regional Committees for Medical and Health Research Ethics. The MoBa cohort is based on regulations based on the Norwegian Health Registry Act. The current study was approved by The Regional Committees for Medical and Health Research Ethics.