Kindsversuscontinua: a review of psychometric approaches to uncover the structure of psychiatric constructs

Abstract

The question of whether psychopathology constructs are discrete kinds or continuous dimensions represents an important issue in clinical psychology and psychiatry. The present paper reviews psychometric modelling approaches that can be used to investigate this question through the application of statistical models. The relation between constructs and indicator variables in models with categorical and continuous latent variables is discussed, as are techniques specifically designed to address the distinction between latent categories as opposed to continua (taxometrics). In addition, we examine latent variable models that allow latent structures to have both continuous and categorical characteristics, such as factor mixture models and grade-of-membership models. Finally, we discuss recent alternative approaches based on network analysis and dynamical systems theory, which entail that the structure of constructs may be continuous for some individuals but categorical for others. Our evaluation of the psychometric literature shows that the kinds-continua distinction is considerably more subtle than is often presupposed in research; in particular, the hypotheses of kinds and continua are not mutually exclusive or exhaustive. We discuss opportunities to go beyond current research on the issue by using dynamical systems models, intra-individual time series and experimental manipulations.

Evidence that psychopathology symptom networks have limited replicability.

“…These changes are routinely recommended in the network analysis literature (Borsboom & Cramer, 2013; Borsboom et al, 2016; Cramer & Borsboom, 2015; Cramer et al, 2010a; Rhemtulla et al, 2016), and would represent a necessary step for these models to live up to their promise. Researchers should also routinely examine the generalizability of findings from psychopathology networks, including the presence, strength and direction of specific edges and the centrality of individual nodes, by replicating them in multiple samples (cf.…”

Latent Trajectories of Common Mental Health Disorder Risk Across 3 Decades of Adulthood in a Population-Based Cohort

“…Latent variable methods that have been used to study the structure of mental health disorder comorbidity have traditionally been divided into person-centered (eg, latent class analysis) and variable-centered (eg, factor analysis) approaches. 41 The latter approaches have often found that mental health disorders are described by 2 factors-an internalizing (mood and anxiety) and an externalizing (behavior and substance use) factor-with comorbidity occurring both within and between domains. [42][43][44] Person-centered approaches aim to identify homogeneous latent subgroups within a heterogeneous population.…”

Development and Validation of Personality Disorder Spectra Scales for the MMPI–2–RF

“…Indeed, multiple, narrow-band, homogenous construct scales in personality assessment are often recommended (Nunnally, 1962;Smith, McCarthy, & Zapolski, 2009;Tellegen et al, 2003). Yet, viewing personality constructs as kinds (categories) versus continua or spectra belies the subtlety that the category-dimension distinction itself might lie on a continuum (Borsboom et al, 2016;Wright, 2011). This issue also applies in biological taxonomy, and the pragmatic nature of the nosological construct is important to consider (Zacher, 2008).…”