Genetic data from more than 200,000 people reveals PTSD, like many other psychiatric disorders, is highly polygenic. Six loci harbor variants were strongly associated with an increased risk of PTSD. The loci hints that inflammatory and immune mechanisms may be involved in the disorder. The study also revealed a significant overlap with 21 genes implicated in depression, schizophrenia, neuroticism, insomnia, asthma, and coronary artery disease.