Dissociative identity disorder: out of the shadows at last?

Dissociative Experiences, Borderline Personality Disorder Features, and Childhood Trauma: Generating Hypotheses from Data-Driven Network Analysis in an International Sample

Dissociation is a multifaceted phenomenon that occurs in various mental disorders, including borderline personality disorder (BPD), but also in non-clinical populations. Severity of childhood trauma (abuse, neglect) plays an important role in the development of dissociation and BPD. However, the complex interplay of different dissociative symptoms, BPD features, and self-reported childhood trauma experiences is not yet fully understood. Graph-theoretical network analysis can help to better understand such multivariate interrelations. Objective: This study aimed to investigate associations between self-reported dissociation, BPD features, and childhood trauma experiences using a graph-theoretical approach. Data was collected online via international mental health platforms and research sites. N = 921 individuals (77.4% female) were included; 40% reported pathological levels of dissociation. Variables were assessed with established psychometric scales (Dissociative Experiences Scale; Personality Assessment Inventory Borderline Features Scale; Childhood Trauma Questionnaire) and analyzed within a partial correlation network. Positive bivariate correlations between all variables were found. When accounting for their mutual influence on each other, dissociation was predominantly connected to BPD features with effect sizes between rp = .028 and rp = .126, while still showing a slight unique relationship with physical neglect (rp = .044). Findings suggest close associations between dissociative experiences and BPD features. While childhood trauma plays an important role in the development of dissociation and BPD, its recall may not fully explain their current co-occurrence. Prospective studies are needed to shed more light on causal pathways to better understand which factors contribute to dissociation and its link to BPD (features).

Inter-identity amnesia in dissociative identity disorder resolved: A behavioural and neurobiological study

INTRODUCTION

Dissociative identity disorder (DID) is characterised by, among others, subjectively reported inter-identity amnesia, reflecting compromised information transfer between dissociative identity states. Studies have found conflicting results regarding memory transfer between dissociative identity states. Here, we investigated inter-identity amnesia in individuals with DID using self-relevant, subject specific stimuli, and behavioural and neural measures.

METHODS

Data of 46 matched participants were included; 14 individuals with DID in a trauma-avoidant state, 16 trauma-avoiding DID simulators, and 16 healthy controls. Reaction times and neural activation patterns related to three types of subject specific words were acquired and statistically analysed, namely non-self-relevant trauma-related words (NSt), self-relevant trauma-related words from a trauma-avoidant identity state (St), and trauma-related words from a trauma-related identity state (XSt).

RESULTS

We found no differences in reaction times between XSt and St words and faster reaction times for XSt over NSt. Reaction times of the diagnosed DID group were the longest. Increased brain activation to XSt words was found in the frontal and parietal regions, while decreased brain activity was found in the anterior cingulate cortex in the diagnosed DID group.

DISCUSSION

The current study reproduces and amalgamates previous behavioural reports as well as brain activation patterns. Our finding of increased cognitive control over self-relevant trauma-related knowledge processing has important clinical implications and calls for the redefinition of "inter-identity amnesia" to "inter-identity avoidance".

Identity state-dependent self-relevance and emotional intensity ratings of words in dissociative identity disorder: A controlled longitudinal study

INTRODUCTION

Dissociative identity disorder (DID) is characterized by, among others, amnesic episodes and the recurrence of different dissociative identity states. While consistently observed in clinical settings, to our knowledge, no controlled research study has shown the degree to which different identity states report autobiographical knowledge over time. Hence, the current study investigates self-relevance and emotional intensity ratings of words longitudinally.

METHODS

Data of 46 participants were included: 13 individuals with DID, 11 DID-simulating actors, and a control group of 22 paired individuals. Individuals with DID and DID simulators participated once in the neutral identity state (NIS) and once in the trauma-related dissociative identity state (TIS). The control group paired 11 healthy controls with 11 participants with posttraumatic stress disorder (PTSD) as a NIS-TIS pair. Self-relevance ratings of different word types were collected in a baseline and a follow-up session, on average 6 weeks apart. A mixed ANOVA design was used to assess the effects of group, session, word type, and dissociative identity state.

RESULTS

All participants in TIS and individuals with DID in NIS rated self-relevant trauma-related words more negatively. In the NIS, the control group rated self-relevant trauma-related words as less negative, whereas the ratings of simulating actors were intermediate. There was no group-dependent longitudinal effect for intensity ratings.

CONCLUSIONS

This study was the first to confirm clinical observations that self-relevant and emotional processing are different between individuals with DID and controls, but consistent over time. Actors were unable to perfectly simulate DID. The finding that ratings of self-relevant trauma-related words differ between subgroups as included in the study is in line with clinical observations.

Conceptualizing multiplicity spectrum experiences: A systematic review and thematic synthesis

BACKGROUND

Dissociative identity disorder and depersonalization-derealization have attracted research and clinical interest, facilitating greater understanding. However, little is known about the experience of multiplicity of self outside of traumagenic or illness constructs. Consequently, this systematic review explored how people identifying as having multiple selves conceptualize their experiences and identity.

METHODS

A comprehensive search of qualitative studies reporting lived experiences of multiplicity was conducted through PsycINFO, PubMed and Scopus (PROSPERO ID: CRD42021258555). Thirteen relevant studies were retrieved (N = 98, 16-64 years, conducted in the United Kingdom, the United States, Hungary and Poland).

RESULTS

Using line-by-line thematic synthesis, four analytical themes were developed: multiplicity: disorder versus experience; impact of understanding multiplicity; importance of supporting multiplicity; and continuum of experiences.

DISCUSSION

This review highlights heterogeneity within multiplicity-spectrum experiences, emphasizing the need for person-centred, individualized understanding, separate from mental health conceptualizations. Therefore, training in person-centred individualized care to promote self-concept clarity is needed across health, education and social care. This systematic review is the first to synthesize voices of people with lived experience across the multiplicity spectrum, demonstrating how qualitative research can contribute to advancing our understanding of this complex phenomena with the community, acknowledging reciprocal psychosocial impacts of multiplicity and providing valuable recommendations for services.

A neurostructural biomarker of dissociative amnesia: a hippocampal study in dissociative identity disorder

BACKGROUND

Little is known about the neural correlates of dissociative amnesia, a transdiagnostic symptom mostly present in the dissociative disorders and core characteristic of dissociative identity disorder (DID). Given the vital role of the hippocampus in memory, a prime candidate for investigation is whether total and/or subfield hippocampal volume can serve as biological markers of dissociative amnesia.

METHODS

A total of 75 women, 32 with DID and 43 matched healthy controls (HC), underwent structural magnetic resonance imaging (MRI). Using Freesurfer (version 6.0), volumes were extracted for bilateral global hippocampus, cornu ammonis (CA) 1-4, the granule cell molecular layer of the dentate gyrus (GC-ML-DG), fimbria, hippocampal-amygdaloid transition area (HATA), parasubiculum, presubiculum and subiculum. Analyses of covariance showed volumetric differences between DID and HC. Partial correlations exhibited relationships between the three factors of the dissociative experience scale scores (dissociative amnesia, absorption, depersonalisation/derealisation) and traumatisation measures with hippocampal global and subfield volumes.

RESULTS

Hippocampal volumes were found to be smaller in DID as compared with HC in bilateral global hippocampus and bilateral CA1, right CA4, right GC-ML-DG, and left presubiculum. Dissociative amnesia was the only dissociative symptom that correlated uniquely and significantly with reduced bilateral hippocampal CA1 subfield volumes. Regarding traumatisation, only emotional neglect correlated negatively with bilateral global hippocampus, bilateral CA1, CA4 and GC-ML-DG, and right CA3.

CONCLUSION

We propose decreased CA1 volume as a biomarker for dissociative amnesia. We also propose that traumatisation, specifically emotional neglect, is interlinked with dissociative amnesia in having a detrimental effect on hippocampal volume.

The brain-body disconnect: A somatic sensory basis for trauma-related disorders

Although the manifestation of trauma in the body is a phenomenon well-endorsed by clinicians and traumatized individuals, the neurobiological underpinnings of this manifestation remain unclear. The notion of somatic sensory processing, which encompasses vestibular and somatosensory processing and relates to the sensory systems concerned with how the physical body exists in and relates to physical space, is introduced as a major contributor to overall regulatory, social-emotional, and self-referential functioning. From a phylogenetically and ontogenetically informed perspective, trauma-related symptomology is conceptualized to be grounded in brainstem-level somatic sensory processing dysfunction and its cascading influences on physiological arousal modulation, affect regulation, and higher-order capacities. Lastly, we introduce a novel hierarchical model bridging somatic sensory processes with limbic and neocortical mechanisms regulating an individual's emotional experience and sense of a relational, agentive self. This model provides a working framework for the neurobiologically informed assessment and treatment of trauma-related conditions from a somatic sensory processing perspective.

False Memory Researchers Misunderstand Repression, Dissociation and Freud

Various authors have argued that dissociative amnesia is a synonym for repressed memories, recovered memories are almost always false memories, and dissociative amnesia and dissociative identity disorder are not valid disorders. These authors commit numerous errors of logic and scholarship; they misunderstand Freud's thinking about childhood sexual abuse, dissociation and repression and blame both Freudian repression theory and Freudian therapists for an epidemic of false memories. In fact, however, Freudian repression theory is based on the assumption that the childhood sexual abuse never happened. Extreme skeptics about dissociative amnesia do not understand they are actually in agreement with Freudian repression theory. These errors and other failures of logic and scholarship are analyzed and critiqued in the present paper.

Dissociation, trauma, and borderline personality disorder

Dissociation is a complex phenomenon, which occurs in various clinical conditions, including dissociative disorders, (complex) post-traumatic stress disorder (CPTSD, PTSD), and borderline personality disorder (BPD). Traumatic stress is considered an important risk factor, while the etiology of dissociation is still debated. Next to traumatic experiences, temperamental and neurobiological vulnerabilities seem to contribute to the development of dissociation. Stress-related dissociation is a prevalent symptom of BPD, which may interfere with psychosocial functioning and treatment outcome. More research in the field is strongly needed to improve the understanding and management of this complex phenomenon. This article collection brings together research on dissociation and trauma, with a special focus on BPD or sub-clinical expressions of BPD. In this editorial, recent conceptualizations of dissociation and relevant previous research are introduced in order to provide a framework for this novel research.

Dissociative identity state-dependent working memory in dissociative identity disorder: a controlled functional magnetic resonance imaging study

BACKGROUND

Memory function is at the core of the psychopathology of dissociative identity disorder (DID), but little is known about its psychobiological correlates.

AIMS

This study aims to investigate whether memory function in DID differs between dissociative identity states.

METHOD

Behavioural data and neural activation patterns were assessed in 92 sessions during an n-back working memory task. Participants were people with genuine diagnosed DID (n = 14), DID-simulating controls (n = 16) and a paired control group (post-traumatic stress disorder (n = 16), healthy controls (n = 16)). Both DID groups participated as authentic or simulated neutral and trauma-related identity states. Reaction times and errors of omission were analysed with repeated measures ANOVA. Working memory neural activation (main working memory and linear load) was investigated for effects of identity state, participant group and their interaction.

RESULTS

Identity state-dependent behavioural performance and neural activation was found. DID simulators made fewer errors of omission than those with genuine DID. Regarding the prefrontal parietal network, main working memory in the left frontal pole and ventrolateral prefrontal cortex (Brodmann area 44) was activated in all three simulated neutral states, and in trauma-related identity states of DID simulators, but not those with genuine DID or post-traumatic stress disorder; for linear load, trauma-related identity states of those with genuine DID did not engage the parietal regions.

CONCLUSIONS

Behavioural performance and neural activation patterns related to working memory in DID are dependent on the dissociative identities involved. The narrowed consciousness of trauma-related identity states, with a proneness to re-experiencing traumatising events, may relate to poorer working memory functioning.

The Policy Alignment of the British False Memory Society and the British Psychological Society

This paper describes the alignment between the goals of the British False Memory Society (BFMS) and a group of sympathetic academics within the British Psychological Society (BPS). Since the 1990s, the policy formation process of the BPS has excluded critical colleagues concerned with child protection and the demonstration of the link between childhood adversity and adult mental health problems. Those involved in the nexus between the BPS and BFMS have focused singularly on the experimental evidence for false-positive outcomes and have systematically excluded a consideration of false negatives. We describe how this biased policy development emerged and was maintained. We discuss this skewed policy formation with reference to social network formation in professional life, as well as the wider context of child abuse in society.

Explanatory hypotheses of the ecology of new clinical presentations of Dissociative Identity Disorders in youth

Dissociative Identity Disorders (DIDs) are controversial psychiatric conditions encountered in clinical practice and nosology. DID as described in the international classifications has little similarity with the clinical picture of "DID" met in current youth psychiatry. From this Perspective, we hypothesize that this current clinical presentation does not satisfy the categorical criteria of the international classifications. Based on the two terminological challenges related to the definition of DID (i.e., the notion of dissociative disorders and the different meanings of the term identity), we propose to differentiate two distinct entities from each other. The first is medical and listed in diagnostic criteria of international classifications; the second comes from popular culture and refers to the vast majority of clinical presentations received in daily clinical practice-presented under the term Dissociative Identity Conditions (DIC). Since the status of DIC is a hot topic in current clinical psychiatry, we aim to identify eight possible explanations that can be provided to support its occurrence: (1) impact of iatrogenicity; (2) factors of suggestibility and desire for social acceptability; (3) psychoanalytic explanations; (4) neuropsychological explanations; (5) socio-cognitive explanations; (6) emotional labeling; (7) narrative explanations; (8) and transient illnesses explanations. In conclusion, we sustain that DIC results from a narrative interpretation of medical discourse by popular culture, developing in patients presenting undeniable distress. Such a transient disease fits in an ecological niche, which echoes the values of society, persisting under the action of a need for narrative continuity of the self.

The utility of the Structured Inventory of Malingered Symptomatology for distinguishing individuals with Dissociative Identity Disorder (DID) from DID simulators and healthy controls

BACKGROUND

Individuals with dissociative identity disorder (DID) have complex symptoms consistent with severe traumatic reactions. Clinicians and forensic assessors are challenged by distinguishing symptom exaggeration and feigning from genuine symptoms among these individuals. This task may be aided by administering validity measures.

OBJECTIVE

This study aimed to document how individuals with DID score on the Structured Inventory of Malingered Symptomatology (SIMS). The second objective was to compare coached DID simulators and healthy controls to DID patients on the SIMS's total score and subscales. The third objective was to examine the utility rates of the SIMS in distinguishing simulated DID from clinically diagnosed DID.

METHOD

We compared SIMS data gathered from participants from two Dutch sites, one Swiss site and one U.S. site. Sixty-three DID patients were compared to 77 coached DID simulators and 64 healthy controls on the SIMS. A multivariate analysis compared the groups on the SIMS total scores and subscales, and post-hoc Games Howell tests and univariate ANOVAs examined differences between the groups. Utility statistics assessed the accuracy of the SIMS in distinguishing clinical from simulated DID.

RESULTS

DID simulators scored significantly higher than DID individuals and healthy controls on every SIMS subscale as well as the total score. The majority (85.7%) of the individuals with DID scored above the cut-off, which is typically interpreted as indicative of possible symptom exaggeration. DID individuals scored higher than the healthy controls on every subscale except Low Intelligence, even after controlling for dissociation. The subscales and items most frequently endorsed by the DID group are consistent with symptoms associated with complex trauma exposure and dissociative reactions. The SIMS total score had a sensitivity of 96% but an unacceptably low specificity of 14%.

CONCLUSIONS

The findings indicate that the instrument is not accurate in assessing potential symptom exaggeration or feigning in DID.