Self-reports of personality functioning and depression are practically fungible: Commentary on Kerber et al. (2026)

This article comments on Kerber et al. (see record 2027-04247-002) examining the prospective correlates of depression (DEP) and personality functioning (PF) in a very large sample of individuals followed via an ecological momentary assessment framework. Using sophisticated bifactor modeling to control for the problematically large latent correlation between the two constructs (the authors report correlations of .75 and .87, depending on measurement approach), the authors suggest that PF and DEP have distinct affective signatures with important ramifications for how treatment is tailored. We argue in this commentary that the very strong latent correlations between PF and DEP, along with nearly identical regression weights in predicting various outcomes (profile agreement across outcomes, r = .95), indicates that there is no practical difference between these two constructs as typically measured. The authors believe the bifactor models allow them to disentangle PF and DEP, but this raises the "perils of partialing." The empirical profiles manifested by the original and residualized latent scores for PF bear no relation to one another (profile agreement, r = -.06), and 53% of their regression weights change direction when comparing the two. We also raise concerns with the viability of their bifactor models, particularly for PF. The residualized PF factor is relatively weak, changes fairly dramatically across analyses, and is unlikely to replicate across samples. Ultimately, we believe Kerber et al. (2026) suggestion that PF and DEP are distinct with differing treatment implications is unsupported by their data. (PsycInfo Database Record (c) 2026 APA, all rights reserved).