Analyses adjusting for the genetic signals attributable to other major psychiatric disorders verified shared heritability with these other disorders while simultaneously confirming residual, distinct heritability for PTSD. The high rg between PTSD symptom subdomains, which do not include overlapping items, supports the coherence of PTSD as a diagnostic construct from a biological perspective: that is, the same genetic predisposition underlies different symptoms that have previously been identified as syndromic. Genomic structural equation modeling recapitulated genetic and phenotypic correlations between PTSD subdomains; this suggests that each PTSD subdomain is largely explained by the same genetic architectures. Our model also suggests that, whereas PTSD symptoms constitute a genetically distinct and cohesive module, hyperarousal may be a relevant subdomain linking the genetic and phenotypic relationships between PTSD, anxiety, major depressive disorder, and neuroticism.
