Comparisons of our CFA with other similar studies of combined Axis I and II disorders (Kendler et al., 2011; Kotov et al., 2011; Markon, 2010; Roysamb et al., 2011) are constrained by variations in samples populations, disorder assessment, and the presence of additional factors other than internalizing/externalizing dimensions that can influence PD factor loadings (e.g., Thought Disorder). Although internalizing and externalizing factors are present in each study, these factors are separate for Axis I and II disorders in Kendler et al. (2011) and Roysamb et al. (2011). In each study ASPD loadings for the externalizing factor stand apart from other PDs, with lower but significant loadings for borderline and other Cluster B disorders. Cluster A and C PDs load on the internalizing factor, but schizoid and schizotypal PDs have higher loadings for a Thought Disorder factor (Kotov et al., 2011). In Roysamb et al. (2011) both of the PD factors (Cognitive-relational Disturbance and Anhedonic Introversion) have moderately high correlations with each other and internalizing Axis I disorders.
