POLYGENIC PREDICTIONS OF INTERNALIZING PROBLEMS AND SUICIDAL BEHAVIORS IN YOUTH

• Published in: European neuropsychopharmacology Vol. 75; p. S36
• Main Authors: Morneau-Vaillancourt, Geneviève, Voronin, Ivan, Ouellet-Morin, Isabelle
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-10-2023
• ISSN: 0924-977X; 1873-7862
• DOI: 10.1016/j.euroneuro.2023.08.074

Internalizing problems are among the most frequent psychological difficulties in young people, with approximately 10% to 25% of adolescents and young adults experiencing severe and clinically-relevant anxiety and depressive symptoms (Lu, 2019; Racine et al., 2021; Tiirikanen et al., 2019). Internalizing problems often persist over time, can predict long-term mental health problems, and are major risk factors for suicidal behaviors. Genetically sensitive studies show that genetic factors account for a substantial proportion of individual differences in internalizing problems, and that polygenic scores can be used to predict these genetic susceptibilities. However, the mechanisms and developmental pathways by which polygenic scores are associated with internalizing problems remain unclear. This symposium integrates findings from longitudinal population-based studies from the UK and Canada to provide new insights into the ways by which polygenic scores can be applied to better understand individual differences in internalizing disorders and suicidal behaviors in young people. The symposium opens with evidence from expression-based polygenic scores, informed from weighted gene co-expression network analysis conducted on rats' social behaviors, predicting internalizing problems in adolescents and adults from ALSPAC and the UK Biobank. This provides new promising avenues for examining how individual differences in child behavior are associated with later psychopathology using functional genomics translational tools. The next talk presents a gene-by-gene interaction model in which polygenic scores for depression and ADHD interact to predict suicide attempt, but not ideation, at 20 years old in two longitudinal population-based studies from Canada, the Quebec Longitudinal Study of Child Development (QLSCD) and the Quebec Newborn Twin Study (QNTS). This talk shows that the joint risk of different polygenic scores, rather than polygenic scores individually, increase risk for suicide attempt in young people and that the genetic underpinnings of suicide attempt may be different than that of suicide ideation. The third presentation features a longitudinal sequential model where socioemotional difficulties assessed at 4 waves from 12 to 17 years old, including depressive symptoms, school dropout risk, and peer victimization, mediate the associations between polygenic scores and suicidal behaviors from 17 to 23 years old. This integrative longitudinal analysis, conducted using data from the QLSCD, highlights some of the development pathways by which polygenic score may be linked to suicidal behaviors in emerging adulthood. The fourth talk explores the mechanisms of intergenerational transmission of anxiety and mood problems in twins from the QNTS using a new model of genetic transmission that accounts for assortative mating and populations stratification. Findings suggests that parents' polygenic scores for internalizing and externalizing problems may be associated with their children's anxiety and mood problems over and above child's polygenic scores, pointing at the possibility of environmentally mediated transmission. The symposium concludes with integrative comments from a discussant with broad experience in behavioral genetics in the context of developmental research.