Functional Magnetic Resonance Imaging of Personality Switches in a Woman with Dissociative Identity Disorder
... These studies have shown regional cerebral blood flow (rCBF) or glucose metabolism (CMRglu) changes in the temporal, parietal (implicated in dissociative and conversion phenomena), and orbitofrontal (likely involved in the integration of the self) cortices, in the hippocampus (involved in memory and in the removal of traumatic events), in the basal ganglia, and in other areas. However, they have reached different, and at times conflicting, conclusions, finding out hyperactivation of brain areas in some cases [12][13][14], and hypoactivation in others [15]. It is also unclear whether these changes involve more often the left or right hemisphere, albeit recent evidence suggests greater damage of the former. ...
... Based on these criteria, we analyzed 61 studies, from which we excluded 48 studies, of which 26 were unrelated to the subject, 6 were case reports/case studies [15,[23][24][25][26][27], 1 was focused on schizophrenia [28], 1 was conducted on adolescents with post-traumatic stress disorder [29], 1 was conducted on healthy subjects [30], 7 used structural neuroimaging techniques [31][32][33][34][35][36][37], and 3 were not focused on dissociative disorders [38][39][40]. We finally included 13 studies published between 2006 and 2022 [14,33,34,[41][42][43][44][45][46][47][48][49][50]. ...
... The hypoactivation of the caudate in dissociative disorders during egocentric tasks has been confirmed by fMRI findings [46], whilst DID patients' caudate nucleus hyperactivates during traumatic identity state condition, in response to personal trauma scripts [34]. The latter can be explained by the fact that the dorsal striatum i.e., caudate nucleus is involved both in the switch between identity states and in the maintenance of the altered identity state [15,41,50,71]. ...
Background:
Dissociative disorders encompass loss of integration in essential functions such as memory, consciousness, perception, motor control, and identity. Nevertheless, neuroimaging studies, albeit scarce, have suggested the existence of particular brain activation patterns in patients belonging to this diagnostic category. The aim of this review is to identify the main functional neuroimaging correlates of dissociative disorders.
Methods:
we searched the PubMed database to identify functional neuroimaging studies conducted on subjects with a diagnosis of a dissociative disorder, following the PRISMA guidelines. In the end, we included 13 studies in this systematic review, conducted on 51 patients with dissociative identity disorder (DID), 28 subjects affected by depersonalization disorder, 24 with dissociative amnesia, and 6 with other or not specified dissociative disorders.
Results:
Prefrontal cortex dysfunction seems prominent. In addition, changes in the functional neural network of the caudate are related to alterations of identity state and maintenance of an altered mental status in DID. Another role in DID seems to be played by a dysfunction of the anterior cingulate gyrus. Other regions, including parietal, temporal, and insular cortices, and subcortical areas were reported to be dysfunctional in dissociative disorders.
Conclusions:
Prefrontal dysfunction is frequently reported in dissociative disorders. Functional changes in other cortical and subcortical areas can be correlated with these diagnoses. Further studies are needed to clarify the neurofunctional correlations of each dissociative disorder in affected patients, in order to identify better tailored treatments.
... Two fMRI case studies have begun to identify brain activity implicated in this transition, also colloquially termed "switching." One study identified differential activity in the hippocampus, parahippocampal gyrus, medial temporal regions, substantia nigra, and globus pallidus, depending on which state the individual was transitioning to (Tsai, Condie, Wu, & Chang, 1999). In another case, researchers implicated pre and postcentral gyrus, nucleus accumbens, and lateral prefrontal cortex in the switching process (Savoy, Frederick, Keuroghlian, Wolk, 2012;. ...
... The hippocampus is centrally involved in learning and memory processing (Squire & Zola-Morgan, 1991), and is sensitive to the neurotoxic effects of chronically activated stress hormones (Conrad, 2008). The majority of studies find that the hippocampus is smaller and abnormally shaped in DID groups compared to nonpsychiatric control groups (Chalavi et al., 2015a;Chalavi et al., 2015b;Ehling et al., 2008;Irle, Lange, Sachsse, & Weniger, 2009;Tsai et al., 1999;Vermetten, Schmahl, Lindner, Loewenstein & Bremner, 2006). In addition to group level comparisons, some work has also demonstrated a negative correlation between hippocampal size and dissociative symptom severity in DID samples or mixed samples that include some individuals with DID (Chalavi et al., 2015b;Ehling et al., 2008;Stein, Koverola, Hanna, Torchia & McClarty, 1997). ...
... One of the largest neuroimaging studies of PTSD to date definitively demonstrated smaller hippocampal volume in PTSD versus trauma exposed controls (Logue et al., 2018). As discussed earlier, smaller hippocampal volume has also been demonstrated in DID and dissociative disorder cohorts (Chalavi et al., 2015a;Chalavi et al., 2015b;Ehling et al., 2008;Irle et al., 2009;Tsai et al., 1999;Vermetten et al., 2006;however, c.f., Weniger et al., 2008 for contrasting evidence). Furthermore, hippocampal volume was negatively associated with the severity of trauma history (Chalavi et al., 2015a;Chalavi et al., 2015b). ...
... Many academics have attempted to explain how trauma and memory interact in people with dissociative identity disorder [15]. An investigation into the relationship between the brain and the process of changing personalities used magnetic resonance imaging to pinpoint the processes involved. ...
... According to the study's findings, a patient's bilateral hippocampus, along with the right parahippocampal gyrus, right medial temporal lobe, globus pallidus, and substantianigra, are all suppressed throughout the switching process. Nevertheless, research indicates that the right hippocampus generally becomes more active during the process of healing from split personality, with no other parts of the brain showing any subdued activity [15]. ...
This paper provides an overview of Dissociative Identity Disorder (DID), its etiology, cognitive aspects, and treatment options. It explains the concept of dissociation and dissociative disorders, leading to the specific focus on DID. The etiology section discusses the multifaceted nature of DID, including biological factors like genetic vulnerabilities and neurobiological abnormalities. Psychological factors, particularly trauma and maladaptive schemas, and social factors, including societal influences and media portrayals, are also explored. This paper delves into cognitive abilities and their impact on individuals with the disorder. Like the relationship between sleep disturbances, trauma, dissociation, and cognitive abilities in individuals with DID and post-traumatic stress disorder (PTSD). The last part focuses on its treatment approaches, the holistic treatment approach that includes symptom reduction, engagement with traumatic memories, and integration and rehabilitation. Psychotherapy, such as cognitive behavioral therapy and eye movement desensitization and reprocessing, is the primary treatment modality, while medication may be used. This work also discusses the need for further research. It discusses potential connections between childhood trauma and cognitive strategies, the role of DID in enhancing aggression and self-protection abilities, and the impact of comorbid PTSD on treatment outcomes. By addressing these research gaps, more effective treatments for DID can be developed.
... autobiographical, they do not show the classic signs of heart rate variability, such as increased heart rate, systolic blood pressure, or the brain network patterns indicative of emotional hyperarousal. Instead, they exhibit a pattern of emotional overmodulation, including increased activation in the medial prefrontal cortex, insula, and amygdala (Tsai et al., 1999;Reinders et al., 2003Reinders et al., , 2006Reinders et al., , 2012Reinders et al., , 2014Lanius et al., 2010;Schlumpf et al., 2013). In this regard, it is of utmost importance to mention two important articles in which the same authors report, with incontrovertible evidence by means of functional and structural magnetic resonance imaging, the presence in clients confronted with their own traumatic memory of neurobiological alterations in the amygdala and prefrontal cortex associated with dissociative symptoms demonstrating its presence as a protective factor against the distress caused by revisiting the trauma (Lanius et al., 2010;Nardo et al., 2013). ...
... Recent studies using brain imaging technology provide independent corroboration for the reality of switching from one alter to another (Tsai, Condie, Wu, & Chang, 1999) and for the diagnosis as a whole (Reinders et al., 2006: Sar, Unal, Kiziltan, Kundakci, & Ozturk, 2001. There is also growing evidence for its validity, reliability, and similar prevalence in various countries (e.g., Boon & Draijer, 1991;Coons, Bowman, Kluft, & Milstein, 1991;Dell & O'Neil, 2009;Tutkun et al., 1998). ...
... Brain imaging studies on dissociative disorders have focused on two issues: the brain imaging correlates of dissociation per se , and the brain imaging diff erences between dissociative patients and normal controls (or other psychiatric patients). Signifi cant brain-imaging diff erences have been found between (a) diff erent types of dissociative parts of the patient's personality in DID patients (Reinders, Nijenhuis, Paans, Korf, Willemsen, & Den Boer, 2006 ; see Nijenhuis,Chapter 38 ,and Lebois et al.,Chapter 24 ,this volume), (b) dissociative responses and nondissociative responses to trauma-related scripts as elements of PTSD patients' responses to triggers (Lanius, Williamson, Boksman, Densmore, Gupta, Neufeld, Gati, & Menon, 2002 ;see Schiavone & Lanius, Chapter 39 , this volume) including comparisons of the dissociative subtype to other types of PTSD (Lanius et al., 2018 ); (c) perfusion before versus perfusion during switching in DID patients ( Tsai, Condie, Wu, & Chang, 1999 ;Savoy et al., 2012 ); and (d) the cerebral perfusion of dissociative patients versus that of normal controls ( Ş ar, Ü nal, K ı z ı ltan, Kundak çı , & Ö zt ü rk, 2001 ; Ş ar, Ü nal, & Ö zt ü rk, 2007 ). ...
... Brain imaging studies on dissociative disorders have focused on two issues: the brain imaging correlates of dissociation per se , and the brain imaging diff erences between dissociative patients and normal controls (or other psychiatric patients). Signifi cant brain-imaging diff erences have been found between (a) diff erent types of dissociative parts of the patient's personality in DID patients (Reinders, Nijenhuis, Paans, Korf, Willemsen, & Den Boer, 2006 ; see Nijenhuis,Chapter 38 ,and Lebois et al.,Chapter 24 ,this volume), (b) dissociative responses and nondissociative responses to trauma-related scripts as elements of PTSD patients' responses to triggers (Lanius, Williamson, Boksman, Densmore, Gupta, Neufeld, Gati, & Menon, 2002 ;see Schiavone & Lanius, Chapter 39 , this volume) including comparisons of the dissociative subtype to other types of PTSD (Lanius et al., 2018 ); (c) perfusion before versus perfusion during switching in DID patients ( Tsai, Condie, Wu, & Chang, 1999 ;Savoy et al., 2012 ); and (d) the cerebral perfusion of dissociative patients versus that of normal controls ( Ş ar, Ü nal, K ı z ı ltan, Kundak çı , & Ö zt ü rk, 2001 ; Ş ar, Ü nal, & Ö zt ü rk, 2007 ). ...
This chapter explores the most pertinent research questions to understand and advance the study of dissociation. Drawing
on specifi c themes, recommendations for future work are outlined at the end of each section. Our chapter in the fi rst edition
of this book still contains questions empirically unanswered (e.g., genetics and neurobiology of dissociative disorders, dissociation
in other psychiatric disorders). We will focus in this chapter on the most pressing questions that currently need to
inform the scientifi c understanding of dissociation.
... w 1999 rokupodczas kierowanego przez badacza przełączenia na osobowość alternatywną wykazali obustronne hamowanie hipokampa (silniejsze po stronie prawej), pola przyhipokampowego oraz małych regionów istoty czarnej i gałki bladej. Zdaniem autorów przy przełączeniu z osobowości alternatywnej na natywną (native) prawy hipokamp wykazywał szczególną aktywność, zdecydowanie większą niż w samym stanie natywnym (Tsai et al., 1999). Z kolei Schlumpf i wsp. ...
Explaining the biology of dissociative identity disorder and its clinical aspects is one of the major challenges in modern neuroscience. The complexity and the unique nature of this disorder, coupled with insufficient biopsychological models needed for creating universal therapeutic procedures, make the treatment difficult. The vast majority of neuroimaging studies in dissociative identity disorder patients proved to be inconclusive. Abnormalities of particular brain structures do not explain the wide range of symptoms in dissociative identity disorder. Moreover, the findings are partly contradictory. Collecting adequate representative study samples is difficult and most reports are in fact single case studies. On top of that, meta-analyses show that patients with dissociative identity disorder usually present with additional mental problems, which makes interpretation of neuroimaging data extremely difficult. Nowadays, scientific research on dissociative identity disorder focuses on child trauma and its influence on the development of the central nervous system. This article is an overview of recent research on the neurobiology of dissociative identity disorder, with particular emphasis on the impact of childhood trauma on the development of the central nervous system. It focuses on hypotheses attempting to capture the specific dynamics of neural activity leading to neural network fragmentation, and uses the dynamical systems theory to describe this phenomenon.
Volumes of the right and left anterior temporal lobes and hippocampal formations were measured from magnetic resonance images in 52 healthy volunteers, aged 20-40 years. Subjects were selected by age, sex, and handedness to evaluate possible effect of these variables. Data were normalized for variation in total intracranial volume between individuals. Right-left asymmetry in the volumes of the anterior temporal lobes and hippocampal formations was a normal finding. The anterior temporal lobe of the non-dominant (right) hemisphere was larger than the left by a small (mean right-left difference, 2.3 cm3) but statistically significant amount (P less than .005) in right-handed subjects. No significant effect of age or sex was seen in normalized right or left anterior temporal lobe volume. The right hippocampal formation was larger than the left for all subjects by a small (mean right-left difference, 0.3 cm3) but statistically significant amount (P less than .001). No effect of age, sex, or handedness was seen in normalized hippocampal formation volumes.
Substantial evidence from animal studies suggests that enhanced memory associated with emotional arousal results from an activation of beta-adrenergic stress hormone systems during and after an emotional experience. To examine this implication in human subjects, we investigated the effect of the beta-adrenergic receptor antagonist propranolol hydrochloride on long-term memory for an emotionally arousing short story, or a closely matched but more emotionally neutral story. We report here that propranolol significantly impaired memory of the emotionally arousing story but did not affect memory of the emotionally neutral story. The impairing effect of propranolol on memory of the emotional story was not due either to reduced emotional responsiveness or to nonspecific sedative or attentional effects. The results support the hypothesis that enhanced memory associated with emotional experiences involves activation of the beta-adrenergic system.
The existence and characteristics of multiple personality disorder (MPD) have been debated from the time of the first case reports in the 19th century. The dispute has never been resolved, and MPD has become the most controversial syndrome known to mental health professionals.
This timely work examines MPD from an empirical viewpoint, describing the research that has been done on the disorder, as well as providing in-depth analysis of how MPD has developed over the years in relation to the media. The book identifies the earliest origins of MPD in published literature and traces the course of its development as a concept to the present. Existing data on MPD are presented in a detailed review of the current state of knowledge of the disorder including clinical description, delineation from other disorders, family history studies, follow-up studies, and laboratory documentation. The authors also point out specific areas of research that is needed before psychiatry can consider MPD an adequately validated diagnosis. This critical approach is designed to provide direction to researchers in the pursuit of a better understanding of MPD and to provide clinicians with a valuable guide. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
TO determine whether physical match between studied and tested items influences blood flow increases in the hippocampal formation associated with recognition memory, positron emission tomography (PET) was used to measure changes in regional cerebral blood flow while healthy volunteers made old/new judgements about line drawings of objects. Some objects were tested in the same size and orientation as they had appeared earlier during the study phase of the experiment; other objects were tested in a different size or orientation than when they were studied. Blood flow increases in the vicinity of the hippocampal formation were observed in the same object condition compared with the size change and the orientation change conditions, even though recognition accuracy was affected significantly only by orientation change. Results add to previous findings suggesting that physical similarity between studied items and test cues may contribute to hippocampal activation during episodic retrieval.
We evaluated a new magnetic resonance (MR)-based technique for performing volumetric measurements of temporal lobe structures. The technique was designed to assist in making the clinical diagnosis of dementia of the Alzheimer type (DAT). We chose specific anatomic regions of interest because of their known involvement in memory function and in the neuropathology of DAT and used a regression model to assess the effects of age on the volumes of the anterior temporal lobe (ATL) and the hippocampal formation (HF). These measurements were normalized by total intracranial volume (TIV). The volumetric measurements of both the normalized ATL and HF were significantly smaller (p less than 0.001) in DAT patients (N = 20) than in controls (N = 22), but the HF volumes provided much better separation between the two groups. Eighty-five percent of the DAT patients fell below the range of the HF/TIV measurement for the control subjects. This separation held up over the entire age range studied. Normalized volumes of both the HF and ATL decreased with age significantly for both the DAT patients and the controls. These results support the contention that MR-based HF volumetric measurements are accurate in differentiating DAT patients from cognitively normal elderly individuals. This technique may be a useful adjunct in making the clinical diagnosis of DAT.
Brain maps were recorded on a patient with a multiple personality disorder (10 alternate personalities). Maps were recorded with eyes open and eyes closed during 2 different sessions, 2 months apart. Maps from each alternate personality were compared to those of the basic personality "S", some maps were similar and some were different, especially with eyes open. Findings that were replicated in the second session showed differences from 4 personalities, especially in theta and beta 2 frequencies on the left temporal and right posterior regions. A rank ordering of the differences in the brain maps of the alternate personalities from S were similar to the rank ordering of the differences in personality characteristics, as judged by the psychiatrist dealing with this patient. Maps from S acting like some of her personalities or from a professional actress portraying the different personalities did not reveal significant differences. Some of these findings are consistent with those in the literature, and the importance of detecting artifact in the raw EEG recording is emphasized.
Twelve patients with clinical and EEG manifestations reminiscent of temporal lobe epilepsy reported symptoms of dissociative states. In seven of these patients, the clinical picture was consistent with multiple personality, whereas the other five had the illusion of supernatural possession. These cases suggest that in selected instances dissociative states may constitute complex behavioral manifestations of chronic limbic epilepsy.