New paper: differential variability of variables drives network structure

In psychopathological networks, we often model ordinal items (problems or symptoms) that are not normally distributed, especially in general population samples. But if a variable shows a floor effect, meaning that the mean is close to 0, it often has a small variance, which in turn means that the variable …

R tutorial: power issues & robustness of network models

A new paper by Mohammad Afzali and colleagues was published a few days ago in the Journal of Affective Disorders, entitled “A Network Approach to the Comorbidity between Posttraumatic Stress Disorder and Major Depressive Disorder: the Role of Overlapping Symptoms”. The authors estimate the network structure of 36 symptoms in …

Collected presentations of ABCT 2016 network talks

The Association for Behavioral and Cognitive Therapies (ABCT) has traditionally been a conference of clinical research with a limited amount of methodological talks. This year, there were a number of symposia on network research, focusing on both idiographic and nomothetic aspects, although the majority of talks used regularized partial correlation …

Network talks at ABCT convention, October 27-30 New York

The Association for Behavioral and Cognitive Therapies (ABCT) hosts its 50-year anniversary conference in New York City in a few days. I browsed through the program and found 4 different symposia in which presenters will talk about empirical psychopathological network research, covering eating and weight disorders, OCD, anxiety disorders, and …

R tutorial: how to identify communities of items in networks

A problem we see in psychological network papers is that authors sometimes over-interpret the visualization of their data. This pertains especially to the layout and node placement of the graph, for instance: do nodes in the networks cluster in certain communities. Below I will discuss this problem in some detail, …

New “Psychological Dynamics” Facebook group

Sacha Epskamp had the great idea to create the public Facebook group Psychological Dynamics. The group serves as a central place to share and discuss news, blogs and publications related, but not limited to, psychological research on dynamical systems, complex systems, network models, time-series analysis, causal discovery and phase transitions. …

2 PhD positions on psychological network research (Groningen, NL)

There is a vacancy for a PhD position on critical transitions in psychopathology amongst adolescents at the University of Groningen (The Netherlands). The position is funded by a prestigious European Research Council (ERC) grant, and supervised (among others) by Hanneke Wigman, Marieke Wichers, and Catharina Hartman, who all have had …

Dynamical systems study follows 1 psychotic patient for 1 full year

When we recently submitted a review paper on empirical network studies in psychopathology, we realized that the majority of prior papers had focused on the analyses of groups, e.g. depressed patients, psychotic patients, or people with autism. Fewer studies had looked into the question of the dynamic character of symptoms …

Expected influence: a new centrality metric by Robinaugh et al. 2016

When we estimate the centrality of nodes in networks, one metric that is commonly used is node strength centrality or degree centrality. In unweighted networks were edges are either 0 or 1, this is simply the sum of edges. Let’s create a brief example in R: we create an adjacency …

Call for papers: special issue on PTSD network studies

The European Journal of Psychotraumatology has announced a call for papers for a special issue entitled “PTSD Symptomics: Analyzing individual PTSD symptoms and their network configurations in traumatized populations”. Cherie Armour, Miranda Olff, and me will serve as editors for this special issue. In summary, we are looking for papers …