A review of dissociation and dissociative disorders

Differential effects of childhood abuse and neglect: mediation by posttraumatic distress in neurotic disorder and negative symptoms in schizophrenia?

Dissociation, though understood as a response to trauma, lacks a proven etiology. The assumption of a dose-response relationship between trauma, dissociation and Schneiderian symptoms led to the proposal of a dissociative subtype of schizophrenia characterized by severe child maltreatment, dissociation and psychosis. Child maltreatment and dissociation are common features of neurotic disorders as well, and the link between trauma, dissociation, and hallucinations is not specific for schizophrenia. This study compares childhood abuse and neglect, posttraumatic distress and adult dissociation in patients with psychotic vs. non-psychotic disorder. Thirty-five participants with non-psychotic disorder and twenty-five with schizophrenia were analyzed using the Scale for the Assessment of Positive Symptoms (SAPS), the Scale for the Assessment of Negative Symptoms (SANS), the Montgomery-Åsberg Depression Rating Scale (MADRS), the Posttraumatic Stress Diagnostic Scale PDS (PDS), the Childhood Trauma Questionnaire (CTO) and the Arbeitsgemeinschaft Methodik und Dokumentation in der Psychiatrie (AMDP)-module on dissociation. Trauma and clinical syndromes were compared by means of T-testing and logistic regression between 1) the diagnoses and 2) groups with and without post-traumatic stress disorder (PTSD), marked dissociation and psychotic symptoms. While non-psychotic disorder was related to abuse, schizophrenia showed an association with neglect. Childhood trauma predicted posttraumatic symptomatology and negative symptoms. Childhood abuse and neglect may effectuate different outcomes in neurotic and psychotic disorder. The underlying mechanisms, including dissociation, dovetail with cognitive, emotional and behavioural changes involved in depression, posttraumatic distress and chronic schizophrenia symptoms rather than being directly linked to trauma.

A more proximal impact of dissociation than of trauma and posttraumatic stress disorder on schneiderian symptoms in patients diagnosed with schizophrenia

BACKGROUND

Dissociation is often related to psychologic trauma and is also commonly correlated with posttraumatic stress disorder (PTSD). Schneiderian symptoms occur in dissociative disorder and PTSD, whereas dissociation and trauma are also frequent in patients with schizophrenia. Dissociation and schneiderian symptoms may reflect posttraumatic symptomatology in some patients diagnosed with schizophrenia who might not develop PTSD.

METHOD

Seventy-one patients completed an interview assessing symptoms of schizophrenia, depression, dissociative disorder, and PTSD. Data were collected using the Positive and Negative Syndrome Scale, the Montgomery-Asberg Depression Rating Scale, the Arbeitsgemeinschaft Methodik und Dokumentation in der Psychiatrie scale for dissociation, and a Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition-based questionnaire. Multiple analysis of covariance was used to compare psychopathologic measures between groups with or without PTSD criteria A1 and A2, PTSD, and high and low levels of dissociation, controlling for substance abuse.

RESULT

Trauma and dissociation were associated with more severe symptoms of schizophrenia. Especially high dissociation was associated with an increase in symptom load, whereas criterion A and PTSD had little or no such effect.

DISCUSSION

In the present study, those with more severe schizophrenic and depressive symptoms were also characterized by high dissociation. The possible relation to trauma and schizophrenic diathesis is discussed along with the limitations of the study.

Hemispheric laterality and dissociative tendencies: Differences in emotional processing in a dichotic listening task

The present work investigates whether the hemispheric processing of both verbal and emotional stimuli, studied by means of a dichotic listening task, differs between normal high and low dissociators as assessed by the Dissociative Experiences Scale (DES; Bernstein & Putnam (1986). Development, reliability and validity of a dissociation scale. Journal of Nervous and Mental Disease, 174(2), 727-735). Two groups of subjects (50 high and 50 low dissociators), participated in the experiment. The task consisted in identifying both verbal and emotional stimulus-targets, respectively, on successive sessions. Reaction time and response accuracy were registered and analysed using ANOVA (Analysis of Variance). The interaction between stimuli (verbal, emotional), channel (right ear, left ear), and dissociation level (high, low) reached statistical significance in terms of accuracy measures (d': F(1,98)=4.75; p<.05). Both high and low dissociators exhibited the expected right ear advantage (REA effect) on verbal targets. On the other hand, whereas low dissociators exhibited the expected left ear advantage (LEA effect) on emotional targets, high dissociators failed to follow this typical pattern of hemispheric asymmetry: both hemispheres exhibited similar performances. These results confirm the hypothesis that dissociation is related to changes in hemispheric processing, specifically of emotional information.

Familial and social support as protective factors against the development of dissociative identity disorder

The incidence of dissociative identity disorder (DID) is strongly correlated with exposure to serious physical and sexual abuse. Although studies of more than 1,000 DID sufferers indicate that severe child abuse is a predisposing factor in 95% to 98% of cases (B. Braun, 1988), abuse alone is not, in fact, predictive of DID (B. Rind & P. Tromovitch, 1997). Disorganized/disoriented attachment style and the absence of social and familial support, in combination with abuse history, best predict DID (D. Howe, 2006; R. Kluft, 1984; K. Lyons-Ruth, L. Dutra, M. Schuder, & I. Bianchi, 2006). Individuals who are securely attached are less likely to develop serious psychopathology in the event of abuse and are more likely to build a strong extrafamilial system of support--also a protective factor against psychopathology (S. Asher & J. Parker, 1989; D. Howe, M. Brandon, D. Hinings, & G. Schofield, 1999; G. Ladd & B. Golter, 1988). Recognition of the significance of secure attachment and familial and social support as protective factors against the development of DID suggests social intervention as an important area of research to mitigate the psychological consequences of insecure attachment, social disconnection, and abuse.

Dissociative experiences in obsessive-compulsive disorder and trichotillomania: clinical and genetic findings

A link between dissociation proneness in adulthood and self-reports of childhood traumatic events (including familial loss in childhood, sexual/physical abuse and neglect) has been documented. Several studies have also provided evidence for an association between dissociative experiences and trauma in patients with various psychiatric disorders, including post-traumatic stress disorder, borderline personality, dissociative identity and eating disorders. Based on the relative paucity of data on dissociation and trauma in obsessive-compulsive disorder (OCD) and trichotillomania (TTM), the primary objective of this study was to examine the relationship between trauma and dissociative experiences (DE) in these two diagnostic groups. Furthermore, the availability of clinical and genetic data on this sample allowed us to explore clinical and genetic factors relevant to this association. A total of 110 OCD and 32 TTM patients were compared with respect to the degree of dissociation (using the Dissociative Experiences Scale [DES]) and childhood trauma (using the Childhood Trauma Questionnaire [CTQ]). Patients were classified on the DES as either "high" (mean DES score >/= 30) or "low" (mean DES score < 30) dissociators. Additional clinical and genetic factors were also explored with chi-square and t tests as appropriate. A total of 15.8% of OCD patients and 18.8% of TTM patients were high dissociators. OCD and TTM groups were comparable on DES and CTQ total scores, and in both OCD and TTM groups, significant positive correlations were found between mean DES scores and mean CTQ subscores of emotional abuse, physical abuse, sexual abuse, and physical neglect. In the OCD group, high dissociators were significantly younger than low dissociators, and significantly more high dissociators than low dissociators reported a lifetime (current and past) history of tics (P <.001), Tourette's syndrome (P =.019), bulimia nervosa (P =.003), and borderline personality disorder (P =.027). In the TTM group, significantly more high dissociators than low dissociators reported (lifetime) kleptomania (P =.005) and depersonalisation disorder (P =.005). In the Caucasian OCD patients (n = 114), investigation of genetic polymorphisms involved in monoamine function revealed no significant differences between high and low dissociator groups. This study demonstrates a link between childhood trauma and DE in patients with OCD and TTM. High dissociative symptomatology may be present in a substantial proportion of patients diagnosed with these disorders. High dissociators may also be differentiated from low dissociators on some demographic features (e.g., lower age) and comorbidity profile (e.g., increased incidence of impulse dyscontrol disorders). Additional work is necessary before conclusions about the role of monoaminergic systems in mediating such dissociation can be drawn.

Acute stress disorder: a synthesis and critique

The diagnosis of acute stress disorder (ASD) was introduced to describe initial trauma reactions that predict chronic posttraumatic stress disorder (PTSD). This review outlines and critiques the rationales underpinning the ASD diagnosis and highlights conceptual and empirical problems inherent in this diagnosis. The authors conclude that there is little justification for the ASD diagnosis in its present form. The evidence for and against the current emphasis on peritraumatic dissociation is discussed, and the range of biological and cognitive mechanisms that potentially mediate acute trauma response are reviewed. The available evidence indicates that alternative means of conceptualizing acute trauma reactions and identifying acutely traumatized people who are at risk of developing PTSD need to be considered.

Dissociative processes and symptoms of posttraumatic stress in Vietnam veterans

The diagnostic taxonomy of posttraumatic stress disorder (PTSD) is a contentious issue. Commentators are divided as to whether PTSD should remain grouped with the anxiety disorders or conceptualized as a dissociative disorder. This study sought to clarify the issue by investigating the extent to which anxiety and dissociative processes differentially predict the severity of each of the three symptoms clusters in PTSD. Seventy-four Australian veterans of the Vietnam War were assessed on measures of dissociation, trait anxiety, and posttraumatic stress symptomatology. Multiple regression analyses showed that all three symptoms clusters were predicted by anxiety, but the clusters differed in the pattern of their relationship with dissociation variables. The failure of pathological dissociation to predict PTSD symptoms prompts a reconsideration of the point at which dissociative mechanisms may impact on this disorder. The findings are consistent with current classification of combat-related PTSD as an anxiety disorder.

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.

Psychological defense styles in women who report childhood sexual abuse: a controlled community study

OBJECTIVE

The psychological defense styles of women who reported childhood sexual abuse were assessed and compared to those of women without childhood sexual abuse.

METHOD

Subjects in a random community sample (N = 354) of New Zealand women were interviewed and completed two relevant questionnaires, the Defense Style Questionnaire and the Dissociative Experiences Scale.

RESULTS

Women reporting childhood sexual abuse showed more immature defense styles, and those who experienced the most severe childhood sexual abuse showed the most immature styles. Dissociation, however, as measured on the Dissociative Experiences Scale, was not linked to childhood sexual abuse.

CONCLUSIONS

Reporting childhood sexual abuse was associated with more immature coping styles, although not dissociation, in this community sample of women. Coping styles are likely to be a major mechanism through which childhood sexual abuse increases rates of later psychological problems.

Dissociative identity disorder: an Australian series

OBJECTIVE

Series of patients fulfilling diagnostic criteria for Dissociative Identity Disorder (DID), otherwise known as multiple personality disorder, have particularly been reported on in North America and increasingly in other countries. The present study investigated the trauma and past treatment histories, symptom profiles and dissociative phenomenology of 62 patients fulfilling diagnostic criteria for DID seen in Brisbane (Queensland, Australia).

METHOD

From 1992, systematic assessments, including the Dissociative Experience Scale and the Dissociative Disorders Interview Schedule, were performed with a personal series of 57 patients with DID seen by one of the authors (WM) and five patients seen by the second author (JB).

RESULTS

The histories of childhood trauma, the clinical profiles and dissociative indices of these patients closely approximate those described in series reported in other countries.

CONCLUSIONS

Patients fulfilling diagnostic criteria for DID are regularly seen in Australian inpatient and outpatient settings. The dissociative symptomatology of the patients examined in the present study represents a significant component of a complex syndrome associated with a history of severe ongoing developmental trauma dating from early childhood.