Genetic overlap between household income and psychiatric disorders

Household income (HI), a significant socioeconomic factor influencing mental health, has seen its association with various mental disorders garnering increasing attention. However, the common genetic basis between HI and psychiatric disorders remains poorly understood. Utilizing genome-wide association study (GWAS) pooled statistics for HI, schizophrenia (SCZ), attention deficit hyperactivity disorder (ADHD), bipolar disorder (BIP), and autism spectrum disorders (ASD), bivariate mixed models of causality (MiXeR) were employed to quantify the shared genetic architecture between HI and psychiatric disorders. The conjunctional false discovery rate (conjFDR) approach was utilized to identify specific shared loci, and the resulting shared genetic loci were analyzed for functional annotation and gene set enrichment. The MiXeR analysis revealed that among the 8.9 K variants affecting HI, 8.7 K were shared with SCZ, 7.8 K with ADHD, 6.2 K with BIP, and 8.7 K with ASD. A total of 344 shared genetic loci were identified between HI and psychiatric disorders using the conjFDR method, with 254 of them being novel. Additionally, the shared loci of HI with SCZ and ADHD mainly demonstrated opposite effect directions, while those with BIP and ASD mainly exhibited mixed effect directions. Functional annotation indicated that the shared genetic loci were predominantly located in intronic and intergenic regions, and enrichment analysis demonstrated that they were involved in nervous system development, multicellular organism development, and neuron differentiation. In conclusion, our study reveals a shared genetic architecture between HI and psychiatric disorders, highlighting common biological processes that may contribute to understanding their complex etiologies and overlapping genetic mechanisms.