Gene-Environment Interplay and Antisocial Behavior PDF

Gene-environment interplay and antisocial behaviour 27 November 2023 14:55 Main Ideas Notes Definitions: Gene-environment correlation (rGE) ○ Genetic influences on the exposure to environments ○ Certain environments only affect those carrying genetic risk ○ or equally genetic risk manifests only und...

Gene-environment interplay and antisocial behaviour 27 November 2023 14:55 Main Ideas Notes Definitions: Gene-environment correlation (rGE) ○ Genetic influences on the exposure to environments ○ Certain environments only affect those carrying genetic risk ○ or equally genetic risk manifests only under certain environmental conditions Why do 'social' environments show genetic influences? ○ Home environment --I> social information processing skills ▪ These skills in turn influence: □ How children behave and respond to parents ® Home environment as perceived by parents □ How parents behave and respond to children ® Home environment as perceived by children Gene-environment correlation (rGE) ○ Three types of rGE: ▪ Passive: correlation between heritable traits and rearing environments ▪ Evocative (or reactive): correlation between heritable traits and behaviour of others in response to those traits ▪ Active (or selective): correlation between heritable traits and environments that individuals with such traits tend to select (1) Passive rGE ▪ Parents and children share genetic vulnerabilities (2) Evocative rGE ▪ Individual's heritable behaviour evokes a response in the environment ▪ For example: □ Different children (with different behavioural repertoires) can evoke different parenting behaviours and feelings in the same adult (3) Active rGE ▪ Tendency to actively seek out environments that reinforce genotypic predispositions ▪ Increases as individuals are more able select an ever-expanding range of environments Notes Investigating evocative rGE ○ Does the adoptive environment correlate with children's genetic risk ▪ ▪ ▪ Genetic influences on environment correlate with genetic influences on behaviour Investigating passive rGE ○ Do measures of adoptive environments correlate with children's traits ○ In children of MZ twins, do children's traits correlate with measures of their aunt/uncle's parenting ○ Does an unrelated prenatal environment correlate with children's traits ▪ Example: Prenatal cross-fostering design: smoking during pregnancy + antisocial behaviour (rice et al., 2009) □ Genes and environments interact Environmental risk/protective effects are conditional on genetic make-up Genetic risk/advantage are conditional on environmental circumstances Environmental hardship needed for genetic risk to express Genes are not destiny Genetic risk can be buffered: Prevention and treatment as positive GxE PSYC0036 Genes and Behaviour Page 1 ▪ Biological parent scores high on antisocial behaviour □ Child at high genetic risk for antisocial behaviour + Child receives more punitive parenting from adoptive parents ▪ Biological parent scores low on antisocial behaviour □ Child at low genetic risk for antisocial behaviour + Child receives less punitive parenting from adoptive parents ○ Does children's behaviour influence family environment - longitudinal multivariate twin design ▪ Example: bidirectional effects of parental negativity and childhood antisocial behaviour □ Parental negativity can have a purely environmental effect on subsequent child AB □ Child AB also has evocative effects on subsequent parental negativity ▪ Example: Bidirectional effects of negative parenting and childhood callous -unemotional (CU) traits □ Cross-lagged effects of negative parenting on CU traits are mostly genetic and shared environmental □ Cross-lagged effects of children’s CU traits on subsequent negative parenting are entirely genetic □ Summary ○ Implications (examp ▪ rGE in the fami □ May rest □ May und ▪ Clinical formula □ Do we ne Part 2: Gene-environment How to investigate GxE Why should we care about rGE? ○ Correlation between an environmental factor and an outcome does not imply causation. ○ Effective interventions require a clear understanding of the causal relationships between environmental factors and health outcomes. ○ Investigating environmental risk factors without accounting for genetic predisposition can lead to inconclusive and misleadin g results. How to detect rGE ○ Are environmental measures heritable - using measures of the environment as outcomes in a twin study Notes □ Rice et al. (2009) found increased antisocial behaviour in children in related, but not unrelated, children of prenatal smokers and non-smokers □ Reduction in birth weight in children in related and unrelated offspring of prenatal smokers and nonsmokers ○ Do measures of the environment share genetic and environmental influences with measures of behaviour - multivariate twin models ○ Does heritability var ▪ Twin design □ Differenc ® Ge ® gen □ Differenc ® En ○ Do environmental in ▪ Adoption desig Investigating active rGE ○ Does the association between environment and behaviour remain when controlling for genetic factors ▪ Genetically sensitive design + specific environmental measures ▪ TenEyck & Barnes (2015): Used twin design to show that once genetic confounds were controlled for, association between peer group and delinquency was no longer significant (i.e., association was accounted for by genetic risk) How to detect rGE in unrelated individuals ○ DNA variants associated with measures of the environment ▪ Molecular genetic designs □ Research on rGE from twin and adoption studies is limited to within family vs. between family factors □ Molecular genetic approaches can estimate the correlation between genetic variants and environments in unrelated individuals ○ Evidence from molecular genetic studies ▪ Candidate gene associations: □ Perceived parenting (Lucht et al 2006) □ Home chaos (Harlaar et al 2005) ▪ Genome-wide associations □ Home chaos (Butcher & Plomin, 2008) ▪ Genome-wide Complex Trait Analyses (GCTA): □ Genetic differences between families account for some of the differences in SES (Trzaskowski et al., 2014) ○ Implications - genetic factors influence environments ▪ Genetic factors influence individuals’ tendency to be exposed to environmental factors that promote different behavioural outcomes ▪ Genetically informative designs are required to fully understand the effects of genetic and environmental factors ▪ Overlooking genetic factors can lead to misinterpretation of putative environmental influences ○ Does susceptibility to ▪ Candidate gen □ Example ® Evi ® Evi □ Example GxE in candidate gene stud ○ Problems ▪ Difficult to repl ▪ Focus on indivi ▪ Often poor me ○ Low replication—Du ▪ 103 studies pu □ 96% repo □ 27% repl Genome-wide GxE studies ○ Line of research in its ○ Requires very large s ○ Example: SNP-enviro le) ily environment: trict the range of possible social inputs over development dermine the parent’s capacity to respond to needs of a child ation: eed to consider a modified delivery model for some families? interaction (GxE) y in different environments ce in heritability as a function of environmental exposure: enetic risk may be exacerbated netic potential may be fully reached only in some environments ce in environmental effects between twins differing for genetic risk: vironmental effects may be stronger in twins higher on genetic risk fluences increase as genetic risk increases gn o environmental influences depend on genotype? e studies : Monoamine oxidase A gene low activity (MAOA-L) and antisocial behaviour idence of role of MAOA-L in aggression from animal model (knock -out mice) idence of environmental risk factors, particularly childhood maltreatment ◊ Genetic, environmental, or GxE : Serotonin-transporter-linked promoter region (5-HTTLPR) and depression dies: licate dual gene variants asures of environment uncan & Keller 2011: blished 2000—2009: orted novel significant results licated s infancy (up to 2021, only 4 GWEIS on psychiatric phenotypes) amples and sophisticated statistical methods onment interaction effects on neuroticism PSYC0036 Genes and Behaviour Page 2