Schizophrenia spectrum disorders and dissociative disorders:The blurry boundaries between categorical diagnoses

In lijn met de onderzoektrend die afstand neemt van categorische modellen van psychopathologie, wordt in dit proefschrift onderzocht in hoeverre schizofrenie spectrum stoornissen en dissociatieve stoornissen categorisch verschillende aandoeningen zijn. Het proefschrift begint met een overzicht van de literatuur gevolgd door nieuw onderzoek dat de uniekheid en de overlap van deze twee diagnostische clusters toetst. Verschillende benaderingen worden hierbij gebruikt, zo wordt er bijvoorbeeld door middel van netwerk analyse specifiek gekeken naar dissociatieve symptomen, die bij beide diagnoses voorkomen. Een andere studie is gericht op het experimenteel induceren van derealisatie, onafhankelijk van schizotypische ervaringen. Hoewel er verschillen zijn tussen schizofrenie spectrum stoornissen en dissociatieve stoornissen, blijkt uit dit proefschrift dat de grenzen tussen deze diagnoses niet zo duidelijk zijn als categorische modellen van psychopathologie, zoals het DSM-5, impliceren. De bevindingen van het proefschrift worden besproken in relatie tot veelbelovende projecten zoals RDoC, HiTOP en het netwerkmodel van psychopathologie

Unique and Overlapping Symptoms in Schizophrenia Spectrum and Dissociative Disorders in Relation to Models of Psychopathology:A Systematic Review

Schizophrenia spectrum disorders (SSDs) and dissociative disorders (DDs) are described in the fifth edition of the Diagnostic and Statistical Manual for Mental Disorders (DSM-5) and tenth edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) as 2 categorically distinct diagnostic categories. However, several studies indicate high levels of co-occurrence between these diagnostic groups, which might be explained by overlapping symptoms. The aim of this systematic review is to provide a comprehensive overview of the research concerning overlap and differences in symptoms between schizophrenia spectrum and DDs. For this purpose the PubMed, PsycINFO, and Web of Science databases were searched for relevant literature. The literature contained a large body of evidence showing the presence of symptoms of dissociation in SSDs. Although there are quantitative differences between diagnoses, overlapping symptoms are not limited to certain domains of dissociation, nor to nonpathological forms of dissociation. In addition, dissociation seems to be related to a history of trauma in SSDs, as is also seen in DDs. There is also evidence showing that positive and negative symptoms typically associated with schizophrenia may be present in DD. Implications of these results are discussed with regard to different models of psychopathology and clinical practice

Three models for a better understanding of schizophrenia

De recente discussie rond het al dan niet bestaan van schizofrenie zal niemand in de geestelijke gezondheidszorg zijn ontgaan. Als onderzoekers naar de classificatie en differentiaaldiagnostiek van schizofrenie-spectrumstoornissen en dissociatieve stoornissen hebben we deze discussie met interesse gevolgd. Deze discussie is niet nieuw.Die woedt namelijk al jaren over het bredere vraagstuk wat psychopathologie precies is. Dit heeft geresulteerd in verschillende modellen van psychopathologie, waarvan de drie belangrijkste zijn: het categorische model, het dimensionele model en het netwerk model

Dissociation and social cognition in schizophrenia spectrum disorder

While there is emerging evidence that dissociation is linked with trauma history and possibly symptoms in schizophrenia, it remains unclear whether dissociation represents a symptom dimensions in its own right in schizophrenia and as such is uniquely related to other features of illness. To explore this issue the current study sought to find out whether dissociation was uniquely related to an index of social cognition closely linked to social functioning, namely affect recognition. We hypothesized that dissociation would be linked with affect recognition because symptoms of dissociation may uniquely disrupt processes which are expected to be needed for correctly recognizing emotions. The sample contained 49 participants diagnosed with a schizophrenia spectrum disorder who were in a non-acute phase of disorder. Participants were concurrently administered the Bell-Lysaker Emotion Recognition Task, the Dissociative Experiences Scale, the Post Traumatic Stress Disorder Checklist and the Positive and Negative Symptoms Scale. Stepwise linear regression analyses were performed in which dissociative symptoms were forced to enter after the other symptoms in order to predict deficits in affect recognition. These analyses revealed that greater levels of dissociative symptoms predicted poorer recognition of negative emotions over and above that of positive, negative, cognitive and PTSD symptoms. Results are consistent with the possibility that dissociation represents a unique dimension o f psychopathology in schizophrenia which may be linked to function. Published by Elsevier B.V