The General Factor of Psychopathology (p): Choosing Among Competing Models and Interpreting p

Over the past 10 years, the general factor of psychopathology, p, has attracted interest and scrutiny. We review the history of the idea that all mental disorders share something in common, p; how we arrived at this idea; and how it became conflated with a statistical representation, the bifactor model. We then leverage data from the Environmental Risk Longitudinal Twin Study to examine the properties and nomological network of different statistical representations of p. We found that p performed similarly regardless of how it was modeled, suggesting that if the sample and content are the same, the resulting p factor will be similar. We suggest that the meaning of p is not to be found by dueling over statistical models but by conducting well-specified criterion-validation studies and developing new measurement approaches. We outline new directions to refresh research efforts to uncover what all mental disorders have in common.

Automated summary

Over the past decade, there has been a growing interest in the general factor of psychopathology, p. This paper reviews the history of the idea that all mental disorders share something in common, p, and how it is often confused with the bifactor model. The authors utilize data from the Environmental Risk Longitudinal Twin Study to examine different statistical representations of p and find that its performance remains consistent regardless of the modeling approach. They suggest that instead of focusing on statistical models, future research should aim to conduct criterion-validation studies and develop new measurement approaches to understand what all mental disorders have in common.