We contrast estimates obtained from the common factor model of neuroticism described above with estimates for a GWAS with an imposed missing structure. We first transformed the binary scale neuroticism items into a smaller number of quantitative scores. To do so, we created three parcels of neuroticism items consisting of 4 items each with scores ranging from 0 to 4, at which point it is appropriate to treat the parcel as continuous.29 Parcels were constructed based on the same EFA results described above and mirrored the composition of the three-factor model, with the exception that the irritability item was included with parcel 2 so as to have an equal distribution of 4 items per parcel. Of the 300,000 participants, 100,000 non-overlapping participants were removed from two of the three parcels for missing data models. The best powered results (indexed by mean χ2 values) were for Genomic SEM of the individual neuroticism items presented above, indicating that construction of composite indices via averaging, though convenient, removes multivariate information that can otherwise be retained with Genomic SEM (Supplementary Table 8). Genomic SEM
