We explore ethical premises and practical implications of using genetic testing to predict suicide risk. Twin studies indicate heritable components of suicide risk, intertwined with the heritability of mental disorders, and possibly other traits. Current genetics research has abandoned searching for single gene Mendelian determinants, in favour of complex probabilistic epigenetic models. Genome-Wide Association Studies (GWAS) might identify thousands of single nucleotide polymorphisms (SNPs), each contributing very little to the variance associated with behavioral phenotypes.