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Dissociative Identity Disorders - Coggle Diagram

- - - - Functional Connectivity Differences
        
        Hopper et al., (2002): Abstract This is the first study to apply EEG coherence analysis to the study of Dissociative Identity Disorder (DID). EEG coherence is argued to be an objective measure of cortical connectivity. Five DID patients were compared to five controls, who were professional actors. Fifteen dissociated DID alter states were studied, as were 15 “alters” simulated by the actor control participants. Comparisons of EEG coherence were made between DID participants and controls. Significant differences in EEG coherence were found in comparing DID host and alter personalities, with coherence found to be lower in the alter personalities. No significant differences were found in comparing DID host personalities and controls. The acted alters matched for age and gender, showed no significant differences in coherence compared to DID alter personalities. The results indicate that EEG coherence may be an objective measure of the neuronal cortical connectivity associated with DID.
        
        Sierk et al., 2018: Abstract: Depersonalisation/Derealisation disorder (DPD) is a chronic and distressing condition characterised by detachment from oneself and/or the external world. Neuroimaging studies have associated DPD with structural and functional alterations in a variety of distinct brain regions. Such local neuronal changes might be mediated by altered interregional white matter connections. However, to our knowledge, no research on network characteristics in this patient population exists to date. In conclusion, in patients with DPD, the structural connectivity between brain regions crucial for multimodal integration and emotion regulation may be altered. Aberrations in fibre tract communication seem to be not solely a secondary effect of local grey matter volume loss but may present a primary pathophysiology in patients with DPD.
      - Structural and Metabolic Differences
        
        Bilhar et al. (2021): Abstract: Dissociative Identity Disorder (DID), an illness characterized by multiple personality states, has long been a controversial diagnosis within the psychiatric community. Demonstrating a neuroanatomical basis for the disorder may help to resolve the controversy. Current literature on the neuroanatomy associated with DID has focused on the hippocampus and amygdala and are inconclusive. This meta-analysis pools the results from n = 3 studies to compare the mean size of these two structures between DID patients, non-DID patients, and healthy controls. Patients diagnosed with both DID & PTSD were found to have smaller hippocampi bilaterally (p< .001) compared to healthy controls; no significant difference was seen in the amygdala. When comparing DID to PTSD patients, the left hippocampus was smaller (p< .001), with a trend for a smaller right hippocampus (p = .06). A comparison of the amygdala was not possible due to a lack of data. These findings suggest that a smaller hippocampus is seen in DID patients beyond what is seen for PTSD, provides neuroanatomical evidence for the memory impairment often seen in DID patients (i.e., amnesia experienced by the host and alters), and presents a potentially novel means to understand this disorder.
        
        Bilhar et al., (2020): Abstract:
        Dissociative Identity Disorder (DID) is a complex and controversial diagnosis that has undergone multiple revisions in the Diagnostic and Statistical Manual of Mental Disorders (DSM) since its recognition in the 1950s (North, 2015). There is not a clear understanding of DID etiopathology, there is no standardized method of diagnosis, and as such, the disorder has been plagued by a history of fabrication case studies (North, 2015). For these reasons, the disorder is opposed by many psychiatrists. To address this controversy, researchers have begun to examine the neurological basis of DID in an effort to provide stronger physical evidence for the disorder. While this line of inquiry is in its infancy, the purpose of the present systematic review is to examine the existing research on the neuroanatomical brain changes associated with DID in an effort to validate the disorder and provide a foundation for the future development of more accurate and reliable diagnostic techniques. When compared to the brains of normal controls, DID patients show smaller cortical and subcortical volumes in the hippocampus, amygdala, parietal structures involved in perception and personal awareness, and frontal structures involved in movement execution and fear learning. DID patients also show larger white matter tracts that are responsible for information communication between somatosensory association areas, basal ganglia, and the precuneus. These neuroanatomical changes appear to be associated with common DID symptoms such as host dissociation, neurotic defense mechanisms, and overall brain activation/circuitry recruitment. This is the first study to systematically review existing MRI data on DID patients and link it to common behavioral symptoms seen with the disorder. The neuroanatomical evidence for the existence of DID as a genuine disorder is growing and the structural differences seen in DID patients’ brains, as reviewed in this report, contribute to that growth.
        
        Chalavi et al., (2015) Abstract: Smaller hippocampal volume has been reported in individuals with post-traumatic stress disorder (PTSD) and dissociative identity disorder (DID), but the regional specificity of hippocampal volume reductions and the association with severity of dissociative symptoms and/or childhood traumatization are still unclear. Brain structural magnetic resonance imaging scans were analyzed for 33 outpatients (17 with DID and 16 with PTSD only) and 28 healthy controls (HC), all matched for age, sex, and education. DID patients met criteria for PTSD (PTSD–DID). Hippocampal global and subfield volumes and shape measurements were extracted. We found that global hippocampal volume was significantly smaller in all 33 patients (left: 6.75%; right: 8.33%) compared with HC. PTSD–DID (left: 10.19%; right: 11.37%) and PTSD-only with a history of childhood traumatization (left: 7.11%; right: 7.31%) had significantly smaller global hippocampal volume relative to HC. PTSD–DID had abnormal shape and significantly smaller volume in the CA2-3, CA4-DG and (pre)subiculum compared with HC. In the patient groups, smaller global and subfield hippocampal volumes significantly correlated with higher severity of childhood traumatization and dissociative symptoms. These findings support a childhood trauma-related etiology for abnormal hippocampal morphology in both PTSD and DID and can further the understanding of neurobiological mechanisms involved in these disorders.
        
        Lemche et al., (2016): Abstract:The cerebral mechanisms of traits associated with depersonalization-derealization disorder (DPRD) remain poorly understood.; Method: Happy and sad emotion expressions were presented to DPRD and non-referred control (NC) subjects in an implicit event-related functional magnetic resonance imaging (fMRI) design, and correlated with self report scales reflecting typical co-morbidities of DPRD: depression, dissociation, anxiety, somatization.; Results: Significant differences between the slopes of the two groups were observed for somatization in the right temporal operculum (happy) and ventral striatum, bilaterally (sad). Discriminative regions for symptoms of depression were the right pulvinar (happy) and left amygdala (sad). For dissociation, discriminative regions were the left mesial inferior temporal gyrus (happy) and left supramarginal gyrus (sad). For state anxiety, discriminative regions were the left inferior frontal gyrus (happy) and parahippocampal gyrus (sad). For trait anxiety, discriminative regions were the right caudate head (happy) and left superior temporal gyrus (sad). Discussion The ascertained brain regions are in line with previous findings for the respective traits. The findings suggest separate brain systems for each trait.; Conclusion: Our results do not justify any bias for a certain nosological category in DPRD.
        
        Reinders et al., (2018): Abstract: Objective: To examine the two constitutes of cortical volume (CV), that is, cortical thickness (CT) and surface area (SA), in individuals with dissociative identity disorder (DID) with the view of gaining important novel insights into the underlying neurobiological mechanisms mediating DID. Methods: This study included 32 female patients with DID and 43 matched healthy controls. Between-group differences in CV, thickness, and SA, the degree of spatial overlap between differences in CT and SA, and their relative contribution to differences in regional CV were assessed using a novel spatially unbiased vertex-wise approach. Whole-brain correlation analyses were performed between measures of cortical anatomy and dissociative symptoms and traumatization. Results Individuals with DID differed from controls in CV, CT, and SA, with significantly decreased CT in the insula, anterior cingulate, and parietal regions and reduced cortical SA in temporal and orbitofrontal cortices. Abnormalities in CT and SA shared only about 3% of all significantly different cerebral surface locations and involved distinct contributions to the abnormality of CV in DID. Significant negative associations between abnormal brain morphology (SA and CV) and dissociative symptoms and early childhood traumatization (0 and 3 years of age) were found. Conclusions In DID, neuroanatomical areas with decreased CT and SA are in different locations in the brain. As CT and SA have distinct genetic and developmental origins, our findings may indicate that different neurobiological mechanisms and environmental factors impact on cortical morphology in DID, such as early childhood traumatization.
        
        Staniloiu & Markowitsch (2012): Abstract: Dissociative disorders are characterized by disturbances of integration of memory, perception, consciousness or identity. They were linked to psychological stress or trauma across various cultures. Dissociative amnesia and fugue, depersonalization disorder, dissociative identity disorder and dissociative disorder not otherwise specified (such as Ganser syndrome) belong to dissociative disorders in DSM-IV-TR. In contrast to DSM-IV-TR, ICD-10 also subsumes the conversion disorder under the category of dissociative (conversion) disorders. Objectives This work's objective is establishing greater recognition of the neural correlates of dissociative disorders. Aims: We review neuroimaging data pertaining to dissociative amnesia and fugue, depersonalization disorder, dissociative identity disorder (multiple personality disorder), Ganser syndrome and various forms of conversion disorder, which were obtained with functional and structural imaging techniques, including diffusion tensor imaging or magnetization transfer ratio measurements. Methods: In addition to imaging data from patients with dissociative amnesia and fugue, a comprehensive review of the scientific literature on the neuroimaging of dissociative disorders was performed. Results: Neuroimaging research data point to metabolic and sometimes even structural brain alterations in dissociative disorders, involving regions that are agreed upon to play roles in mnemonic processing, self referential processing (including body schema), perception, consciousness and/or emotional processing. Conclusions The use of functional and newer structural brain imaging methods has improved and will continue to further our understanding of the neural correlates of dissociative disorders and has provided evidence that environmentally-driven (stress-related) alterations of cognition, identity, body schema, perception, affectivity and behavior are accompanied by metabolic and even structural brain changes.
      - Cognitive Masurements
        
        Dorahy et al., (2015): Abstract: Despite its long and auspicious place in the history of psychiatry, dissociative identity disorder (DID) has been associated with controversy. This paper aims to examine the empirical data related to DID and outline the contextual challenges to its scientific investigation. METHODS: The overview is limited to DID-specific research in which one or more of the following conditions are met: (i) a sample of participants with DID was systematically investigated, (ii) psychometrically-sound measures were utilised, (iii) comparisons were made with other samples, (iv) DID was differentiated from other disorders, including other dissociative disorders, (v) extraneous variables were controlled or (vi) DID diagnosis was confirmed. Following an examination of challenges to research, data are organised around the validity and phenomenology of DID, its aetiology and epidemiology, the neurobiological and cognitive correlates of the disorder, and finally its treatment.RESULTS: DID was found to be a complex yet valid disorder across a range of markers. It can be accurately discriminated from other disorders, especially when structured diagnostic interviews assess identity alterations and amnesia. DID is aetiologically associated with a complex combination of developmental and cultural factors, including severe childhood relational trauma. The prevalence of DID appears highest in emergency psychiatric settings and affects approximately 1% of the general population. Psychobiological studies are beginning to identify clear correlates of DID associated with diverse brain areas and cognitive functions. They are also providing an understanding of the potential metacognitive origins of amnesia. Phase-oriented empirically-guided treatments are emerging for DID. CONCLUSIONS: The empirical literature on DID is accumulating, although some areas remain under-investigated. Existing data show DID as a complex, valid and not uncommon disorder, associated with developmental and cultural variables, that is amenable to psychotherapeutic intervention.
        
        Huntjens et al., (2015): Abstract: Dissociative experiences are thought to occur acutely (e.g., during or immediately following trauma) or chronically and are considered to reduce the subjective distress accompanying stressful events. Growing evidence is consistent with a model that distinguishes between two qualitatively different types of phenomena—“compartmentalization” and “detachment.” Compartmentalization involves a deficit in the ability to deliberately control processes or actions that would normally be amendable to such control (e.g., amnesia and dissociative identities). Detachment refers to an experienced state of disconnection from the self or the environment (e.g., depersonalization, derealization, and numbing). In the present contribution, we discuss both detachment and compartmentalization phenomena. In addition, we discuss both dissociation as an acute response to trauma and persistent dissociation in the form of the most severe and chronic of the dissociative disorders, dissociative identity disorder (DID). We attend to the burgeoning empirical literature on memory processing and dissociation given the central role of these cognitive operations in the development and maintenance of the dissociative disorders, and more broadly, posttraumatic symptomatology. We end with a more general appeal for more transdiagnostic studies of dissociative phenomena, both in the areas of detachment and compartmentalization, emphasizing that dissociative disorders are not a category of mysterious diagnoses that need to be understood outside of well-known cognitive operations.
        
        Morton (2017): Abstract: Patients diagnosed with dissociative identity disorder (DID) usually present with alternative personality states (alters) who take separate control of consciousness. Commonly, one alter will claim they have no awareness of events which took place when another alter was in control. However, some kinds of material are transferred across the alter boundary. Huntjens et al. devised an objective method of demonstrating such transfer. Methods: In the main study, following Huntjens et al., for three patients, two alters were taught different sets of nouns. The following week, one of the alters was given a recognition memory test including both sets plus distractor words. The patients in the Huntjens experiment responded in the same way to words in both sets. Results: In the present experiment, two of the patients tested had pairs of alters where there was no interference from the material which was presented to the other alter. In one of these cases, there was breakthrough with one pairing of alters, a pattern matched in a subsidiary experiment. Conclusions: The population of individuals with DID are not homogeneous with respect to the depth of the blocking of episodic material from one alter to another.