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

In line with research moving away from categorical models of psychopathology, this PhD dissertation examines to what extent schizophrenia spectrum disorders and dissociative disorders are categorically distinct. The dissertation starts with a review of the literature followed by novel research testing the uniqueness and overlap of these two diagnostic clusters. Various approaches are used in these studies, for example, dissociation, as one of the overlapping symptom, is examined through network analysis and another study was aimed at experimentally inducing experiences of derealization independent of experiences of schizotypy. Although there are some differences between schizophrenia spectrum disorders and dissociative disorders, this dissertation shows that the boundaries between these diagnoses are not as clear as categorical models of psychopathology imply. The findings of the dissertation are discussed in relation to promising projects such as RDoC, HiTOP, and the network model of psychopathology.