We provide two examples of confirmatory factor analysis (CFA) using Genomic SEM. In our first example, we fit a genetic factor model to psychiatric case-control traits. Recent findings indicate that the comorbidity across psychiatric disorders is captured by a general psychopathology factor (i.e., the p-factor) and is widely supported based on previous results.17–21 We tested for the presence of a single common genetic p-factor using Genomic SEM with European-only summary statistics for schizophrenia, bipolar disorder, major depressive disorder (MDD), post-traumatic stress disorder (PTSD), and anxiety (Table S1 for phenotypes and sample sizes). Model fit was adequate (χ2[5] = 89.55, AIC = 109.50, CFI = .848, SRMR = .212). Results indicated that schizophrenia and bipolar disorder loaded the strongest onto the genetic p-factor (Supplementary Figure 1), a pattern of findings that closely replicates prior findings from twin/family studies.19
