Finally, the zygosity interaction term, reflecting whether the strength of the association differed across discordant MZ and DZ pairs was not significant for SA (p=.96) and was nominally significant for NSSI (p=.054). Therefore, we examined the association between EAU and NSSI separately for MZ (n=363) and DZ (n=335) twin pairs (results presented in Table 3). The association was significant for the DZ pairs alone (OR=4.86, 95% CI: 2.15-10.96, p<.01; see Supplemental Table 3 for parameter estimates and test statistics).
