An empirically derived hierarchical tree typology of DSM-5 pathological personality traits in adolescence.

Traditional personality disorder (PD) taxonomies have been developed for adult populations. We aimed to identify an adolescent hierarchical tree typology of PD indicators to provide classification into broad severity classes but also more fine-grained classification within those classes. A large sample of community adolescents (N = 1,940) completed a validated dimensional measure that covers a comprehensive range of pathologically formulated personality traits, the Personality Inventory for DSM-5. Latent class tree modeling suggested three classes at the first level of the tree representing high, medium, and low PD-trait levels-thus spanning the range between normal and pathological personality. These classes were divided into subclasses lower in the hierarchy, which suggested subclinical variants of patterns that are often found in clinical samples, medium levels of externalizing and internalizing behaviors, and differential profiles of thriving in the low-risk classes. The identified classes had promising initial criterion validity based on meaningful relations with self- and peer-reported measures of friendship and social functioning with peers. Our hierarchical PD tree typology may represent groups at differential risk for developing PDs and could therefore be useful for preventive purposes. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Deciding on the Starting Number of Classes of a Latent Class Tree.

In recent studies, latent class tree (LCT) modeling has been proposed as a convenient alternative to standard latent class (LC) analysis. Instead of using an estimation method in which all classes are formed simultaneously given the specified number of classes, in LCT analysis a hierarchical structure of mutually linked classes is obtained by sequentially splitting classes into two subclasses. The resulting tree structure gives a clear insight into how the classes are formed and how solutions with different numbers of classes are substantively linked to one another. A limitation of the current LCT modeling approach is that it allows only for binary splits, which in certain situations may be too restrictive. Especially at the root node of the tree, where an initial set of classes is created based on the most dominant associations present in the data, it may make sense to use a model with more than two classes. In this article, we propose a modification of the LCT approach that allows for a nonbinary split at the root node, and we provide methods to determine the appropriate number of classes in this first split, based either on theoretical grounds or on a relative improvement of fit measure. This novel approach also can be seen as a hybrid of a standard LC model and a binary LCT model, in which an initial, oversimplified but interpretable model is refined using an LCT approach. Furthermore, we show how to apply an LCT model when a nonstandard LC model is required. These new approaches are illustrated using two empirical applications: one on social capital and the other on (post)materialism.

Ethnic variations regarding clinical profiles and symptom representation in prisoners with psychotic disorders.

BACKGROUND: Black and minority ethnic (BME) groups are known to have higher prevalences of psychotic disorders and are over-represented in western penitentiaries and forensic psychiatric institutions. Research from regular mental healthcare settings suggests that they could show different and more severe psychotic symptoms. Aims To explore ethnic variations in severity of symptomatology of BME and non-BME detainees with psychotic disorders. METHOD: In this study, 824 patients with psychotic disorders from seven different ethnic groups, imprisoned in a penitentiary psychiatric centre in the Netherlands, were compared on symptom severity and symptom representation using the BPRS-E clinical interview. Data were analysed by means of a multilevel analysis. RESULTS: BME patients with psychotic disorders are over-represented in forensic psychiatry, and symptom profiles of prisoners with psychotic disorders vary by ethnicity. Additionally, severity levels of overall psychopathology differ between ethnic groups: patients with an ethnic majority status show more severe levels of psychopathology compared with BME patients. CONCLUSIONS: There are differences in symptom severity and symptom profiles between BME patients and non-BME patients. Disregarding these differences could have an adverse effect on the outcome of the treatment. Possible explanations and clinical impact are discussed. Declaration of interest None.

TRACING THE DEVELOPMENT OF TYPEWRITING SKILLS IN AN ADAPTIVE E-LEARNING ENVIRONMENT.

Typewriting studies which compare novice and expert typists have suggested that highly trained typing skills involve cognitive process with an inner and outer loop, which regulate keystrokes and words, respectively. The present study investigates these loops longitudinally, using multi-level modeling of 1,091,707 keystroke latencies from 62 children (M age=12.6 yr.) following an online typing course. Using finger movement repetition as indicator of the inner loop and words typed as indicator of the outer loop, practicing keystroke latencies resulted in different developmental curves for each loop. Moreover, based on plateaus in the developmental curves, the inner loop seemed to require less practice to develop than the outer loop.