Genetic correlates of socio-economic status influence the pattern of shared heritability across mental health traits

Epidemiological studies show high comorbidity between different mental health problems, indicating that individuals with a diagnosis of one disorder are more likely to develop other mental health problems. Genetic studies reveal substantial sharing of genetic factors across mental health traits. However, mental health is also genetically correlated with socio-economic status (SES), and it is therefore important to investigate and disentangle the genetic relationship between mental health and SES. We used summary statistics from large genome-wide association studies (average N similar to 160,000) to estimate the genetic overlap across nine psychiatric disorders and seven substance use traits and explored the genetic influence of three different indicators of SES. Using genomic structural equation modelling, we show significant changes in patterns of genetic correlations after partialling out SES-associated genetic variation. Our approach allows the separation of disease-specific genetic variation and genetic variation shared with SES, thereby improving our understanding of the genetic architecture of mental health.

Automated summary

Epidemiological studies indicate high comorbidity and genetic overlap among different mental health problems, as well as a genetic correlation with socio-economic status. By analyzing large genome-wide association studies and utilizing genomic structural equation modelling, researchers were able to separate disease-specific genetic variation from variation shared with SES, improving the understanding of the genetic architecture of mental health.