Phenomenology of dissociative symptoms: A comparison between individuals with dissociative disorders and high and low dissociative schizophrenia spectrum disorders

Background: The distinction between dissociative disorders (DDs) and schizophrenia spectrum disorders (SSDs) in different categories since DSM-III presumes a clear-cut distinction between both disorders. However, empirical studies did not reveal a clear distinction between the disorders on a symptom level. The aim of the current study was to further examine the overlap and differences in symptoms between DDs and SSDs. Methods: Levels and types of dissociative and psychotic symptoms were compared between 27 DD patients and 51 SSD patients using MANOVA. For a more fine-grained insight, a subgroup analysis was performed with the DD group and 12 individuals with SSD who report many dissociative experiences (SSD-H). Finally, a discriminant analysis was performed to explore if there are symptoms discriminating between the DD group and both SSD groups. Results: Results showed that the DD group experienced higher levels of each type of dissociative symptoms than the total SSD group. The symptoms self-states alters, discontinuities of time, flashbacks, voices, and depersonalization were found to best discriminate between the groups. These differences did not hold in the subgroup analysis between the DD group and SSD-H group, where only differences on the validity scales rare symptoms, attention seeking and factitious behavior were found. Conclusion: It can be stated that none of the dissociative and psychotic symptoms is specific to DDs or SSDs. Therefore it is advisable to be cautious with classifying based on the presence of (certain) symptoms. A transdiagnostic approach towards assessment and treatment, regardless of classification, is indicated.