Objective:
Suicidal behavior is heritable and is a major cause of death worldwide. Two large-scale genome-wide asso-ciation studies (GWASs) recently discovered and cross- validated genome-wide significant (GWS) loci for suicide attempt (SA). The present study leveraged the genetic co-horts from both studies to conduct the largest GWAS meta- analysis of SA to date. Multi-ancestry and admixture-specific meta-analyses were conducted within groups of significant African, East Asian, and European ancestry admixtures.
Methods:
This study comprised 22 cohorts, including 43,871 SA cases and 915,025 ancestry-matched controls. Analytical methods across multi-ancestry and individual ancestry ad-mixtures included inverse variance-weighted fixed-effects meta-analyses, followed by gene, gene-set, tissue-set, and drug-target enrichment, as well as summary-data-based Mendelian randomization with brain expression quantitative trait loci data, phenome-wide genetic correlation, and ge-netic causal proportion analyses.
Results:
Multi-ancestry and European ancestry admixture GWAS meta-analyses identified 12 risk loci at p values <5×10–8. These loci were mostly intergenic and implicated DRD2, SLC6A9, FURIN, NLGN1, SOX5, PDE4B, and CACNG2. The multi-ancestry SNP-based heritability estimate of SA was 5.7% on the liability scale (SE=0.003, p=5.7×10–80). Significant brain tissue gene expression and drug set en-richment were observed. There was shared genetic variation of SA with attention deficit hyperactivity disorder, smoking, and risk tolerance after conditioning SA on both major de-pressive disorder and posttraumatic stress disorder. Genetic causal proportion analyses implicated shared genetic risk for specific health factors.
Conclusions:
This multi-ancestry analysis of suicide attempt identified several loci contributing to risk and establishes significant shared genetic covariation with clinical pheno-types. These findings provide insight into genetic factors associated with suicide attempt across ancestry admixture populations, in veteran and civilian populations, and in at-tempt versus death.