To better understand causation, the associations between PDs and AUD and those between PD traits and AUD were partitioned according to genetic and environmental factors. For this purpose, AE models were favored over ACE models (Supplement, section 4) and are thus presented. Figure 1b shows the estimated cross-sectional and longitudinal biometric path coefficients from modeled liabilities for ASPD and BPD to that of AUD (see Figure 1a for the path diagram). Consistent genetic effects, as well as cross-sectional environmental paths, were found, but the longitudinal environmental paths did not differ from zero statistically. The difference between the genetic and environmental longitudinal paths was more clear for BPD (χ2 = 4.35, d.f. = 1, p = 0.037) than for ASPD (χ2 = 2.12, p = 0.145).
