Abstract:

The co-occurrence of externalizing and internalizing psychopathology problems is the norm rather than the exception. Understanding the externalizing-internalizing co-occurrence depends on theories of psychopathology structure. The splitting-oriented theory treats each internalizing and externalizing problems as relatively separated entity. This theoretical perspective leads to problems in the externalizing-internalizing co-occurrence research, the most problematic of which is that almost every psychopathology problem co-occurs with each other. Thus, it is difficult to ensure whether an observed co-occurrence represents an authentic functional connection between psychopathology problems, or if it is just a spurious relation derived from methodological fallacies.

The p factor theory breaks this logjam. As an innovative theory about the structure of psychopathology, it proposes that an unobserved propensity to psychopathology, the p factor, gives rise to all forms of psychopathology problems, thus leading to the co-occurring phenomenon. Additionally, there are also propensities specific to certain clusters of problems, which are the specific internalizing factor and externalizing factor. Compared to former psychopathology structure theories, the p factor provides a direct theoretical representation of the co-occurrence phenomenon. In terms of methodology, the bi-factor model serves as the statistical representation of the p factor theory. The bi-factor model is characterized by all indicators loading onto a general factor (g factor); meanwhile, certain clusters of indicators also load onto their specific factors (s factors) respectively.

In recent years, there has been an increasing number of empirical studies investigating the externalizing-internalizing co-occurrence from the perspective of p factor theory and utilizing the bi-factor paradigm. When comparing the bi-factor model with other competing models, researchers have consistently found that the bi-factor model best fits psychopathology data, providing strong support for the validity of the p factor theory in delineating psychopathology structure. By integrating predictors into the bi-factor model, researchers have identified important etiology factors. Specifically, the p factor has a solid genetic basis and is related with neurobiological characteristics. Additionally, there is a significant link between the p factor and the temperament of negative emotionality. Individuals with stronger negative emotionality tend to experience the co-occurrence between internalizing and externalizing problems. Contextual factors also contribute to the p factor. For example, adverse family factors, such as poverty, parental substance use, and maternal depression, can place children and adolescents at elevated risks of externalizing-internalizing co-occurrence. Harsh parenting could be a risk factor, while positive parenting practices may protect children from developing psychopathology. Studies on peer and social factors have also revealed that peer victimization and peer rejection play significant roles as etiology factors of the p factor, which in turn may contribute to the development of both externalizing and internalizing problems. Furthermore, by evaluating relations between the outcome variable and the p factor, researchers found that the p factor of children and adolescents correlated with a much wider range of negative outcomes in the future.

Future research should focus on improving the research design and statistical modeling when using the bi-factor paradigm to ensure the reliability and validity of the findings. For instance, employing a multi-informant design can be important and even necessary to prevent potential biases caused by the common-method issue. Additionally, given that general and specific psychopathology factors are theorized as orthogonal to each other, caution should be exercised in allowing correlations among these factors in bi-factor modeling. Furthermore, to enhance the validation of the p factor theory and to develop a comprehensive etiological framework of psychopathology, future research from the p factor perspective should aim to integrate with the perspective of developmental psychopathology. By incorporating developmental perspectives, researchers can gain a more holistic understanding of the development and expression of psychopathology over time.

Key words: psychopathology, externalizing and internalizing problems, co-occurrence, p factor, bi-factor model

摘要： p因素理论是一种颇具创新性的心理病理结构理论,为内外化心理病理问题共发研究提供了新的理论视角和研究方法。本文介绍了p因素理论的主要观点以及p因素理论视角下实证研究的研究方法与重要研究发现,包括心理病理问题p因素的生物、心理、社会环境等方面的相关因素及发展结果。最后,对未来研究提出研究设计、统计建模等方面的建议,并对未来的研究方向进行展望,以期提升研究结论可靠性,完善对心理病理问题的理解。

关键词: 心理病理问题, 内外化问题, 共发, p因素, 双因子模型