We wrote up the core arguments and calculations of this blog post as an article for Lancet Psychiatry. Major depression: a highly heterogeneous disorder Major Depressive Disorder (MDD) is a complex and heterogeneous disorder. The DSM-5 that is commonly used to diagnose patients with MDD requires the presence of at least one of the two… Read more »
Three brief personal updates. After living in 6 countries in the last 12 years; after affairs and short relationships with Ludwig Maximilian’s University Munich, Free University Berlin, University of Michigan, Arizona State University, University of Leuven, and University of Amsterdam; and after 3 years as a very happy postdoc … I thought I should start… Read more »
One of the fundamental shortcomings of the empirical psychological literature on mental disorders, personality aspects, intelligence, or emotions is that there is a lack of depth regarding the discussion what these psychological constructs are. Researchers often use statistical models such as factor models and find 3 depression factors or 5 personality factors, but it remains… Read more »
Our paper “Estimating psychological networks and their accuracy: a tutorial paper” was published in Behavioral Research Methods as open access paper! You can find the full paper here, and the supplementary materials here. In this paper, we raise the possible danger of an upcoming replicability crisis consistent with the rest of psychology, given that we… Read more »
I published a new paper in the Journal of Affective Disorders entitled “The 52 symptoms of major depression: Lack of content overlap among seven common depression scales” (PDF). The paper examines content overlap of 7 common depression scales, and concludes that the scales feature 52 distinct depression symptoms that are listed in the main Figure… Read more »
After reviewing the paper “The relative responsiveness of test instruments can be estimated using a meta-analytic approach: an illustration with treatments for depression” by Kounali et al. 2016, the editor invited me to write a response because I raised the point that a large amount of researchers seem to misunderstand the concept of scale responsiveness…. Read more »
We have a new commentary in Molecular Psychiatry entitled “Problems with latent class analysis to detect data-driven subtypes of depression” (PDF; together with the fantastic Hanna van Loo, Rob Wanders & Klaas Wardenaar). This was a response to numerous papers over the last years that found separate latent classes in depression that may be statistical… Read more »
We have a new network paper out in Psychological Medicine entitled “Network Analysis of Depression and Anxiety Symptom Relations in a Psychiatric Sample” (PDF). I tend to think of the paper as a state-of-the-art replication of the great comorbidity paper by Cramer et al. 2010 who investigated the comorbidity of depression and generalized anxiety disorder…. Read more »
We published a new study in Psychological Assessment a few days ago, and I would like to take the time to explain what these results imply. You can find the full text here. Let me summarize the findings first. We examined 2 crucial psychometric assumptions that are part of nearly all contemporary depression research. We… Read more »
On December 15th, Molecular Psychiatry published our commentary “The volumes of subcortical regions in depressed and healthy individuals are strikingly similar: a reinterpretation of the results by Schmaal et al”. You can find the full text PDF in the above link if you have a subscription to the journal, otherwise see the project’s open science… Read more »
The folks at The Psychologist were kind enough to publish a short overview piece that summarizes the current problems we are facing in depression research, the problematic assumptions the research community holds about depression that have contributed to this dramatic lack of progress that has gone on for over half a century now, and solutions… Read more »
Our new paper “What are ‘good’ depression symptoms? Comparing the centrality of DSM and non-DSM symptoms of depression in a network analysis” was published in the Journal of Affective Disorders (PDF). In the paper we develop a novel theoretical and empirical framework to answer the question what a “good” symptom is. Traditionally, all depression symptoms… Read more »
John McManamy has written a great piece on depression heterogeneity at healthcentral.com that nicely sums up our study “Depression is not a consistent syndrome: an investigation of unique symptom patterns in the STAR*D study” published in the Journal of Affective Disorders (PDF). His main message: The quick takeaway is that not all depressions are the… Read more »
BMC Medicine published our new paper “Depression sum-scores don’t add up: why analyzing specific depression symptoms is essential” (PDF). It was published in the section Current Controversies in Psychiatry that “seeks to address the key challenges in mental health from diagnosis to co-morbidities” and “focuses on precision medicine where advances in genetics, epigenetics, biomarkers, treatment… Read more »
My first solo album I mean paper was released a few days ago ;). My special thanks to Randolph Nesse, Laura Bringmann, Denny Borsboom, and Francis Tuerlinckx for the great support. The publication titled “Problematic assumptions have slowed down depression research: why symptoms, not syndromes are the way forward” is available as open access paper… Read more »