Neurodevelopmental origins of abnormal cortical morphology in dissociative identity disorder.

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.

Is it Trauma- or Fantasy-based? Comparing dissociative identity disorder, post-traumatic stress disorder, simulators, and controls.

OBJECTIVE: The Trauma Model of dissociative identity disorder (DID) posits that DID is etiologically related to chronic neglect and physical and/or sexual abuse in childhood. In contrast, the Fantasy Model posits that DID can be simulated and is mediated by high suggestibility, fantasy proneness, and sociocultural influences. To date, these two models have not been jointly tested in individuals with DID in an empirical manner. METHOD: This study included matched groups [patients (n = 33) and controls (n = 32)] that were compared on psychological Trauma and Fantasy measures: diagnosed genuine DID (DID-G, n = 17), DID-simulating healthy controls (DID-S, n = 16), individuals with post-traumatic stress disorder (PTSD, n = 16), and healthy controls (HC, n = 16). Additionally, personality-state-dependent measures were obtained for DID-G and DID-S; both neutral personality states (NPS) and trauma-related personality states (TPS) were tested. CONCLUSION: For Trauma measures, the DID-G group had the highest scores, with TPS higher than NPS, followed by the PTSD, DID-S, and HC groups. The DID-G group was not more fantasy-prone or suggestible and did not generate more false memories. Malingering measures were inconclusive. Evidence consistently supported the Trauma Model of DID and challenges the core hypothesis of the Fantasy Model.

Volume of discrete brain structures in complex dissociative disorders: preliminary findings.

Based on findings in traumatized animals and patients with posttraumatic stress disorder, and on traumatogenic models of complex dissociative disorders, it was hypothesized that (1) patients with complex dissociative disorders have smaller volumes of hippocampus, parahippocampal gyrus, and amygdala than normal controls, (2) these volumes are associated with severity of psychoform and somatoform dissociative symptoms, and (3) patients who recovered from dissociative identity disorder (DID) have more hippocampal volume that patients with florid DID. The preliminary findings of the study are supportive of these hypotheses. Psychotherapy for dissociative disorders may affect hippocampal volume, but longitudinal studies are required to document this potential causal relationship.

One brain, two selves.

Having a sense of self is an explicit and high-level functional specialization of the human brain. The anatomical localization of self-awareness and the brain mechanisms involved in consciousness were investigated by functional neuroimaging different emotional mental states of core consciousness in patients with Multiple Personality Disorder (i.e., Dissociative Identity Disorder (DID)). We demonstrate specific changes in localized brain activity consistent with their ability to generate at least two distinct mental states of self-awareness, each with its own access to autobiographical trauma-related memory. Our findings reveal the existence of different regional cerebral blood flow patterns for different senses of self. We present evidence for the medial prefrontal cortex (MPFC) and the posterior associative cortices to have an integral role in conscious experience.

Evidence for associations among somatoform dissociation, psychological dissociation and reported trauma in patients with chronic pelvic pain.

This study investigates somatoform as well as psychological dissociation, somatization and reported trauma among patients with chronic pelvic pain (CPP). Women with CPP (n = 52) who were newly referred to a gynecology department, or whose pain had resisted treatment, completed standardized self-report questionnaires and received a structured interview for DSM-IV dissociative disorders. The prevalence of dissociative disorders in the sample was very low. As hypothesized, self-reported somatoform dissociation was positively correlated with self-reported psychological dissociation and features of DSM-IV dissociative disorders; women who reported more serious psychic trauma, in particular sexual and physical abuse, experienced more somatoform and psychological dissociation than women reporting less trauma, or no trauma at all; and the association of somatoform dissociation and reported trauma was stronger than the association of psychological dissociation and trauma. Physical abuse/life threat posed by a person predicted somatoform dissociation best. The results are consistent with findings among psychiatric patients, and, therefore, strengthen the thesis that somatoform dissociation, (features of) dissociative disorder, and reported trauma are strongly intercorrelated phenomena.

Generalized dissociative amnesia: episodic, semantic and procedural memories lost and found.

OBJECTIVE: This review tests Ribot's classic twofold categorization of generalized amnesia (GA) into Type I, total loss of episodic memory, and Type II, additional more or less extensive loss of semantic and/or procedural memory. It also explores his law of regression, according to which, cast in modern terms, recovery of lost procedural and semantic memories precedes recovery of episodic memory, as well as reported aetiological factors. METHOD: Clinically and formally assessed cases of GA, published since 1845, were surveyed and further analysed. RESULTS: Over and above authentic episodic memory loss, cases differed widely in the extent of impairment of semantic and procedural memory. Recovery of semantic and procedural memory often preceded recovery of episodic memory. This particularly applied to authenticated trauma memories. To an extent, lost memories affected current functioning, and in some cases were associated with alternating dissociative personalities. Severe memory distortions upon memory recovery were not reported. Most cases were trauma or stress related, while in some cases the aetiology remained unknown. CONCLUSIONS: Contrary to the view expressed in DSM-IV, which states that dissociative amnesia pertains to an inability to recall personal information, GA may also involve loss and recovery of semantic and procedural memories. Since the loss of various memory types in GA is dimensional rather than categorical, Ribot's typological distinction does not hold. Some of the reviewed cases suggest a trauma-related aetiology. Generalized amnesia of varying degrees of severity can involve delayed retrieval of trauma memories, as well as the loss and delayed retrieval of the premorbid personality.

Prophylactic and therapeutic effects of a humanized monoclonal antibody against the IL-2 receptor (DACLIZUMAB) on collagen-induced arthritis (CIA) in rhesus monkeys.

CIA in the rhesus monkey is an autoimmune-based polyarthritis with inflammation and erosion of synovial joints that shares various features with human rheumatoid arthritis (RA). The close phylogenetic relationship between man and rhesus monkey makes the model very suitable for preclinical safety and efficacy testing of new therapeutics with exclusive reactivity in primates. In this study we have investigated the prophylactic and therapeutic effects of a humanized monoclonal antibody (Daclizumab) against the alpha-chain of the IL-2 receptor (CD25). When Daclizumab treatment was started well after immunization but before the expected onset of CIA a significant reduction of joint-inflammation and joint-erosion was observed. A therapeutic treatment, initiated as soon as the first clinical signs of CIA were observed, proved also effective since joint-degradation was abrogated. The results of this study indicate that Daclizumab has clinical potential for the treatment of RA during periods of active inflammation and suppression of the destruction of the joint tissues.

Effectiveness of couch height-based patient set-up and an off-line correction protocol in prostate cancer radiotherapy.

PURPOSE: To investigate set-up improvement caused by applying a couch height-based patient set-up method in combination with a technologist-driven off-line correction protocol in nonimmobilized radiotherapy of prostate patients. METHODS AND MATERIALS: A three-dimensional shrinking action level correction protocol is applied in two consecutive patient cohorts with different set-up methods: the traditional "laser set-up" group (n = 43) and the "couch height set-up" group (n = 112). For all directions, left-right, ventro-dorsal, and cranio-caudal, random and systematic set-up deviations were measured. RESULTS: The couch height set-up method improves the patient positioning compared to the laser set-up method. Without application of the correction protocol, both systematic and random errors reduced to 2.2-2.4 mm (1 SD) and 1.7-2.2 mm (1 SD), respectively. By using the correction protocol, systematic errors reduced further to 1.3-1.6 mm (1 SD). One-dimensional deviations were within 5 mm for >90% of the measured fractions. The required number of corrections per patient in the off-line correction protocol was reduced significantly during the course of treatment from 1.1 to 0.6 by the couch height set-up method. The treatment time was not prolonged by application of the correction protocol. CONCLUSIONS: The couch height set-up method improves the set-up significantly, especially in the ventro-dorsal direction. Combination of this set-up method with an off-line correction strategy, executed by technologists, reduces the number of set-up corrections required.

Somatoform dissociation discriminates among diagnostic categories over and above general psychopathology.

OBJECTIVE: The primary aim of this study was to investigate the hypothesis that somatoform dissociation would differentiate among specific diagnostic categories after controlling for general psychopathology. METHOD: The Somatoform Dissociation Questionnaire (SDQ-20), the Dissociative Experiences Scale, and the Symptom Checklist-90-R were completed by patients with DSM-IV diagnoses of dissociative disorders (n = 44), somatoform disorders (n = 47), eating disorders (n = 50), bipolar mood disorder (n = 23), and a group of consecutive psychiatric outpatients with other psychiatric disorders (n = 45), mainly including anxiety disorders, depression, and adjustment disorder. RESULTS: The SDQ-20 significantly differentiated among diagnostic groups in the hypothesised order of increasing somatoform dissociation, both before and after statistically controlling for general psychopathology. Somatoform dissociation was extreme in dissociative identity disorder, high in dissociative disorder, not otherwise specified, and increased in somatoform disorders, as well as in a subgroup of patients with eating disorders. In contrast with somatoform dissociation, psychological dissociation did not discriminate between bipolar mood disorder and somatoform disorders. CONCLUSIONS: Somatoform dissociation is a unique construct that discriminates among diagnostic categories. It is highly characteristic of dissociative disorder patients, a core feature in many patients with somatoform disorders, and an important symptom cluster in a subgroup of patients with eating disorders.

Degree of somatoform and psychological dissociation in dissociative disorder is correlated with reported trauma.

In this study, the prevalence and severity of traumatic experiences as reported by patients with dissociative disorders and with other DSM-IV psychiatric diagnoses were compared. Furthermore, the predictive value of emotional, physical, and sexual trauma with respect to somatoform and psychological dissociation was analyzed. In contrast with comparison patients, dissociative disorder patients reported severe and multifaceted traumatization. Physical and sexual trauma predicted somatoform dissociation, sexual trauma predicted psychological dissociation as well. According to the memories of the dissociative disorder patients, this abuse occurred in an emotionally neglectful and abusive social context. Pathological dissociation was best predicted by early onset of reported intense, chronic and multiple traumatization. Methodological limitations restricting causal inferences between reported trauma and dissociation are discussed.

Animal defensive reactions as a model for trauma-induced dissociative reactions.

Patients with complex dissociative disorders remain in alternating psychophysiological states which are discrete, discontinuous, and resistant against integrative tendencies. In this contribution, a parallel is drawn between animal defensive and recuperative states that are evoked in the face of severe threat and the characteristic responses of dissociative disorder patients as displayed in major dissociative states. Empirical data and clinical observations seem to be supportive of the idea that there are similarities between freezing, concomitant development of analgesia and anesthesia, and acute pain in threatened animals and severely traumatized human beings.

Somatoform dissociative symptoms as related to animal defensive reactions to predatory imminence and injury.

The authors hypothesized that there would be a similarity between animal defensive responses to variable predatory imminence and injury and certain somatoform dissociative symptoms of trauma-reporting patients who have dissociative disorder. As a first test of this hypothesis, 12 somatoform symptom clusters consisting of clinically observed somatoform dissociative phenomena were constructed. All clusters discriminated between patients with dissociative disorders (n = 50) and patients with other psychiatric diagnoses (n = 50). Those expressive of the hypothesized similarity--freezing, anesthesia-analgesia, and disturbed eating--belonged to the 5 most characteristic symptoms of dissociative disorder patients. Anesthesia-analgesia, urogenital pain, and freezing symptom clusters independently contributed to predicted presence of dissociative disorder. Using an independent sample, it appeared that anesthesia-analgesia best predicted presence of dissociative disorder after controlling for symptom severity. The results were largely consistent with the hypothesized similarity.

Psychometric characteristics of the somatoform dissociation questionnaire: a replication study.

BACKGROUND: The present study aimed to replicate the results of previous studies concerning the development of two versions of the Somatoform Dissociation Questionnaire. The SDQ-20 evaluates the severity of somatoform dissociative phenomena, and the SDQ-5 is a dissociative disorders screening instrument. METHODS: Thirty-one patients with dissociative disorders and 45 consecutive psychiatric outpatients with other DSM-IV diagnoses completed the SDQ-20 and SDQ-5 as well as the Dissociation Questionnaire which measures psychological dissociation. RESULTS: Mokken scale analysis showed that the items of the SDQ-20 are strongly scalable on a latent unidimensional scale. Internal consistency was high. The SDQ-20 convergent validity was supported by high intercorrelations with the DIS-Q. Dissociative patients obtained significantly higher scores than comparison patients. Patients with dissociative identity disorder scored significantly higher compared to patients with dissociative disorder nos. Sensitivity (94%) and specificity (98%) of the SDQ-5 were very satisfactory, as were, at an estimated prevalence rate of dissociative disorders of 10% among psychiatric patients, positive predictive value (84%) and negative predictive value (99%). CONCLUSIONS: All results replicated the first findings, and therefore corroborate the conclusion that the SDQ-20 and SDQ-5 are instruments of sound psychometric quality, and that somatoform dissociative phenomena are core symptoms of complex dissociative disorders.

The development of the somatoform dissociation questionnaire (SDQ-5) as a screening instrument for dissociative disorders.

Using cases of dissociative disorder (n=50) and other DSM-IV diagnoses (n=50), a somatoform dissociation self-report questionnaire was developed and its capacity to function as a screening device for dissociative disorders was analysed. A list of 75 items was constructed which, according to clinical experience and expert judgement, could reflect instances of somatoform dissociation. Statistical analyses revealed the 20 best discriminating items. Stepwise forward logistic analysis detected five items which, as a group, provided optimal discrimination between the two groups. At an estimated prevalence rate of dissociative disorders of 10% among psychiatric patients the sensitivity would be 94%, the specificity would be 96%, the positive predictive value would be 72%, and the negative predictive value would be 99%. Cross-validation in an independent sample (n=33/42) largely corroborated the initial findings. The SDQ-5 can be used as a brief screening device for dissociative disorders.

The development and psychometric characteristics of the Somatoform Dissociation Questionnaire (SDQ-20).

According to 19th century French psychiatry and contemporary clinical observations, dissociation pertains to both psychological and somatoform components of experience, reactions, and functions. Because such an instrument was lacking, we aimed to develop a self-reporting questionnaire measuring what we propose to call somatoform dissociation. Patients with dissociate disorder and with other DSM-IV psychiatric diagnoses completed a list of 75 items that, according to clinical experience and expert judgment, could reflect instances of somatoform dissociation. Separate logistic analyses and determination of discriminant indices per item revealed 20 items that best discriminated between those with and without dissociative disorders. Mokken analysis showed that these items are strongly scalable on a dimensional latent scale interpreted to measure somatoform dissociation. Reliability of the scale was high. Construct validity was supported by high intercorrelations with the Dissociation Questionnaire, which measures psychological dissociation, and higher scores of patients with dissociative identity disorder compared with patients with dissociative disorders not otherwise specified. In conclusion, the Somatoform Dissociation Questionnaire (SDQ-20) is a scale of good psychometric quality, which measures somatoform dissociation. The symptoms pertain to negative and positive dissociative phenomena, which were well known in 19th century French psychiatry as the mental stigmata and mental accidents of hysteria.