GENETICALLY SHAPED ENVIRONMENTS: THE ROLE OF ACTIVE AND EVOCATIVE GENE-ENVIRONMENT CORRELATIONS IN MENTAL HEALTH

Environmental and lifestyle factors influencing mental health—e.g. SES, diet, sleep, home environment, activieties—are heritable. This gives rise to gene-environment correlation (rGE). rGE can bias genetic effect sizes, Mendelian randomisation studies, and gene-environment interaction estimates. rGEs can also reveal new mechanisms through which genetic risk is expressed. In this symposium we present several studies that explore (active and evocative) rGE using quantitative genetics and GWAS-based approaches, in different cohorts across the world.

Margherita Malanchini will address different forms of gene-environment interplay influencing internalising and externalising problems in childhood and adolescence. The effects of 13 polygenic scores for psychopathology (G), a combination of environmental exposures (E), their additive effect (G+E), interaction (G × E), and correlation (rGE) were examined in 3,337 16-year-olds from the Twins Early Development Study. Results indicated both GxE and rGE, and suggested that individuals may seek or create environments that align with their genetic propensities, which complicates the interpretion of G × E.

Next, Luciana Tovo-Rodrigues will explore recent evidence on the joint contribution of genetic liability and exposure to childhood maltreatment to ADHD symptomatology in young adulthood. Analyses were based on the 2004 Pelotas Birth Cohort, a landmark longitudinal study in Brazil that followed 4,231 individuals from birth. Findings indicated that individuals with higher polygenic scores for ADHD are more likely to have experienced adverse childhood environments. Mediation analysis suggested an evocative rGE mechanism.

Third, Yingjie Shi wil present findings from the longitudinal ABCD study examining how genetic, familial, and dozens of lifestyle and environmental factors contribute—individually and collectively—to adolescent mental health. Lifestyle, especially sleep, had the largest unique influence on internalizing and externalizing problems, while family and school environments were particularly important for externalizing behaviors. Longitudinal analyses revealed widespread bidirectional relationships between lifestyle/environment and mental health traits.

Fourth, Meike Bartels will present two studies of the Netherlands Twin Register converging on evidence that genetic predisposition for wellbeing contributes to shaping supportive environments, consistent with active rGE. A large-scale longitudinal survey showed that higher teenage wellbeing predicts better psychosocial outcomes in early adulthood, with attenuated within-family effects suggesting genetically influenced environmental selection. In a second, Ecological Momentary Assessment study, individuals with higher momentary wellbeing experienced less subsequent social mismatch, indicating that affective states shape social interactions.

Together, these findings from different analyses techniques and separate datasets show how genetically driven behavioural differences can actively, evocatively and reciprocally shape our environments and mental wellbeing. This adds a layer of complexity to genetic mechanisms, and possibly a new dimension of translational potential for behavioural and policy interventions to alter genetic influences to the benefit of mental health. This, and other implications of this work will be the focus of the symposium's discussion, led by Matthew Keller.