Polygenic risk for neuroticism is associated with externalizing symptoms in 2-year-old boys

• Published in: Progress in neuro-psychopharmacology & biological psychiatry Vol. 123; p. 110720
• Main Authors: Liuhanen, Johanna, Kantojärvi, Katri, Acosta, Henriette, Pietikäinen, Johanna T., Nolvi, Saara, Savukoski, Minna, Kylliäinen, Anneli, Pölkki, Pirjo, Karlsson, Hasse, Karlsson, Linnea, Paavonen, E. Juulia, Paunio, Tiina
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 20.04.2023
• Subjects: Adult; Child, Preschool; Cohort Studies; Early childhood; Externalizing symptoms; Female; Genome-Wide Association Study; Humans; Infant; Internalizing symptoms; Male; Multifactorial Inheritance - genetics; Neuroticism; Parents - psychology; Polygenic scores; Neuroticism; Externalizing symptoms; Early childhood; Internalizing symptoms; Polygenic scores
• ISSN: 0278-5846; 1878-4216
• DOI: 10.1016/j.pnpbp.2023.110720

Recent advances in genome-wide association studies have enabled the estimation of genetic risk of complex traits, including neuroticism, with polygenic risk scores (PRS). Neuroticism PRS has been associated with psychiatric disorders and symptoms in adults, but studies in children are scarce. We studied whether neuroticism PRS, and its subscales, worry PRS and depressive affect PRS, were associated with externalizing and internalizing symptoms in 2-year-olds. We also examined parental neuroticism PRSs' association with children's externalizing and internalizing symptoms and whether parental depressive symptoms mediated the effect. Participants from two Finnish birth cohorts, CHILD-SLEEP and FinnBrain Birth Cohort Study, who had DNA and data on Brief Infant-Toddler Social and Emotional Assessment (BITSEA) available were included in the study (N = 806 and N = 987, respectively). PRSs were calculated based on GWAS data from UK Biobank. Child's neuroticism PRS, and its subscale worry PRS, were positively associated with externalizing symptoms in 2-year-old boys, but not in girls. Mother's depressive symptoms mediated the association between maternal neuroticism PRS and externalizing and internalizing symptoms in boys, but not in girls. Our results suggest that neuroticism PRS, and its subscale worry PRS, are associated with externalizing symptoms in already as young as 2-year-old boys, and, that subclinical symptoms of maternal depression that are based on genetic disposition, have an effect on boy's internalizing and externalizing symptoms. As we did not find any associations in girls, our study supports the suggestion that girls and boys may differ in how genetic and environmental factors contribute to their development. •We examined neuroticism PRS and externalizing & internalizing symptoms in children•Child's neuroticism PRS was associated with externalizing symptoms in 2-year-old boys•We found no association in girls•Parents' PRSs & depressive symptoms and child's PRSs were analyzed in path models