Exploring the impact of socioeconomic factors on psychiatric genetics and epigenetics

Because socioeconomic status (SES) has a major impact on mental health, an increasing number of genetic and epigenetic studies are modeling SES to investigate more accurately the molecular basis of psychiatric disorders. SES can also affect genomic studies through several indirect pathways, such as participation bias and gene-environment correlation. Accordingly, our field needs to become more aware of the challenges that SES can introduce in psychiatric genetic and epigenetic research. This symposium will showcase different approaches to explore the dynamics by which SES can affect psychiatric disorders and their comorbidities. Michel Nivard (Vrije Universiteit Amsterdam, The Netherlands) will present results regarding the causal effect of educational attainment on mental illness. Combining results from a within-sibship analysis in the Dutch national registry (N=1.7 million) and a two-sample Mendelian randomization analysis, educational attainment showed a causal effect with depression, alcohol dependence, anxiety, and posttraumatic stress disorder and a bidirectional relationship with attention-deficit hyperactivity disorder. Manuela Kouakou (Yale University, United States) will describe findings regarding the effect of SES on psychiatric and somatic comorbidities of schizophrenia. Leveraging data from the Psychiatric Genomic Consortium, UK Biobank, and FinnGen, this study applied multivariable genetically causal inference methods to estimate whether SES partially contributes to the association of schizophrenia with negative health outcomes such as substance abuse, depression, anxiety, metabolic disorders, cardiovascular diseases, and respiratory diseases. Sarah Paul (Washington University in St. Louis, United States) will present novel findings regarding the interplay of neighborhood and familial SES (i.e., neighborhood poverty and familial income) with polygenic scores (PGS) for educational attainment, intelligence, and executive function in the Adolescent Brain Cognitive Development Study. These results show how neighborhood poverty moderates the influence of educational attainment PGS, such that at high levels of neighborhood disadvantage, genetic propensity toward educational achievement differentiates executive function ability more so than in advantaged environments. Anders Jespersen (Aarhus University, Denmark) will discuss an epigenome-wide association study of area-based SEP deprivation that identified 15 differentially methylated regions that were upregulated during brain development in early childhood and have previously been linked to a host of chronic physical and mental health conditions, in particular of an inflammatory origin. After these four talks, Robbee Wedow (Purdue University, United States) will use his expertise in sociology, demography, and computational genetics to lead a discussion on the themes that emerged across talks and highlight both the challenges and opportunities that lie ahead for sociogenomics research.