To test the indirect effect, bootstrapping procedures in AMOS were used to examine whether impulsiveness mediated the relation between GABRA2 variants and LAPS. Bootstrapping (MacKinnon et al., 2007) is a non-parametric method based on re-sampling with replacement done 2,000 times. We used a 90% confidence interval. We tested the indirect effect of the four SNPs that were associated with both LAPS and impulsiveness.
