Martin J. Dorahy

Evaluation of the Evidence for the Trauma and Fantasy Models of Dissociation

The relationship between a reported history of trauma and dissociative symptoms has been explained in 2 conflicting ways. Pathological dissociation has been conceptualized as a response to antecedent traumatic stress and/or severe psychological adversity. Others have proposed that dissociation makes individuals prone to fantasy, thereby engendering confabulated memories of trauma. We examine data related to a series of 8 contrasting predictions based on the trauma model and the fantasy model of dissociation. In keeping with the trauma model, the relationship between trauma and dissociation was consistent and moderate in strength, and remained significant when objective measures of trauma were used. Dissociation was temporally related to trauma and trauma treatment, and was predictive of trauma history when fantasy proneness was controlled. Dissociation was not reliably associated with suggestibility, nor was there evidence for the fantasy model prediction of greater inaccuracy of recovered memory. Instead, dissociation was positively related to a history of trauma memory recovery and negatively related to the more general measures of narrative cohesion. Research also supports the trauma theory of dissociation as a regulatory response to fear or other extreme emotion with measurable biological correlates. We conclude, on the basis of evidence related to these 8 predictions, that there is strong empirical support for the hypothesis that trauma causes dissociation, and that dissociation remains related to trauma history when fantasy proneness is controlled. We find little support for the hypothesis that the dissociation-trauma relationship is due to fantasy proneness or confabulated memories of trauma.

The distribution of positive psychosis-like symptoms in the population: A latent class analysis of the National Comorbidity Survey

OBJECTIVE Previous research has suggested that psychosis is better described as a continuum rather than a dichotomous entity. This study aimed to describe the distribution of positive psychosis-like symptoms in the general population by means of latent class analysis. METHOD Latent class analysis was used to identify homogeneous sub-types of psychosis-like experiences. Multinomial logistic regression models were used to interpret the nature of the latent classes, or groups, by estimating the associations with demographic factors, clinical variables, and experiences of traumatic events. RESULTS The best fitting latent class model was a four-class solution: a psychosis class, a hallucinatory class, an intermediate class, and a normative class. The associations between the latent classes and the demographic risk factors, clinical variables, and experiences of traumatic events showed significantly higher risks for the psychosis class, the hallucinatory class, and the intermediate class compared to the normative class. Furthermore there appeared to be a grading in the magnitude of the odds ratios: the odds ratios for the psychosis group were generally higher than those for the hallucinatory class, and the odds ratios for the hallucinatory class were generally higher than those for the intermediate class. CONCLUSIONS The latent class analysis showed that psychosis-like symptoms at the population level could be best explained by four groups that appeared to represent an underlying continuum.

Minimization of childhood maltreatment is common and consequential: results from a large, multinational sample using the childhood trauma questionnaire

Childhood maltreatment has diverse, lifelong impact on morbidity and mortality. The Childhood Trauma Questionnaire (CTQ) is one of the most commonly used scales to assess and quantify these experiences and their impact. Curiously, despite very widespread use of the CTQ, scores on its Minimization-Denial (MD) subscale—originally designed to assess a positive response bias—are rarely reported. Hence, little is known about this measure. If response biases are either common or consequential, current practices of ignoring the MD scale deserve revision. Therewith, we designed a study to investigate 3 aspects of minimization, as defined by the CTQ’s MD scale: 1) its prevalence; 2) its latent structure; and finally 3) whether minimization moderates the CTQ’s discriminative validity in terms of distinguishing between psychiatric patients and community volunteers. Archival, item-level CTQ data from 24 multinational samples were combined for a total of 19,652 participants. Analyses indicated: 1) minimization is common; 2) minimization functions as a continuous construct; and 3) high MD scores attenuate the ability of the CTQ to distinguish between psychiatric patients and community volunteers. Overall, results suggest that a minimizing response bias—as detected by the MD subscale—has a small but significant moderating effect on the CTQ’s discriminative validity. Results also may suggest that some prior analyses of maltreatment rates or the effects of early maltreatment that have used the CTQ may have underestimated its incidence and impact. We caution researchers and clinicians about the widespread practice of using the CTQ without the MD or collecting MD data but failing to assess and control for its effects on outcomes or dependent variables.

Auditory hallucinations in dissociative identity disorder and schizophrenia with and without a childhood trauma history: similarities and differences.

Little is known about similarities and differences in voice hearing in schizophrenia and dissociative identity disorder (DID) and the role of child maltreatment and dissociation. This study examined various aspects of voice hearing, along with childhood maltreatment and pathological dissociation in 3 samples: schizophrenia without child maltreatment (n = 18), schizophrenia with child maltreatment (n = 16), and DID (n = 29). Compared with the schizophrenia groups, the DID sample was more likely to have voices starting before 18, hear more than 2 voices, have both child and adult voices and experience tactile and visual hallucinations. The 3 groups were similar in that voice content was incongruent with mood and the location was more likely internal than external. Pathological dissociation predicted several aspects of voice hearing and appears an important variable in voice hearing, at least where maltreatment is present.

Shame and Guilt in Men Exposed to Childhood Sexual Abuse: A Qualitative Investigation

This study examined the experiences of shame and guilt in adult males sexually abused as children. Seven participants attending a service for male sexual abuse completed measures of shame, guilt, dissociation, and childhood trauma history and subsequently participated in a focus group. All participants experienced childhood sexual abuse in the “severe” range and showed elevated scores for shame, guilt, and dissociation. Four superordinate themes with associated subordinate themes emerged: (a) self-as-shame (foundations of self-as-shame, fear of exposure, temporary antidote: connection), (b) pervasiveness and power of doubt and denial (from others, from self, consequences of incredulity), (c) uncontrollability (of problems after disclosure, of rage, of intrusions and emotional pain), and (d) dissociation. Results are discussed with reference to the existing literature and the emerging “self-as-shame” construct, which appeared to encapsulate participants’ view of themselves.

Dissociative identity disorder and memory dysfunction: the current state of experimental research and its future directions

Memory dysfunction is a central feature of dissociative identity disorder (DID). Following the memorial anomalies outlined by Putnam [Putnam, F. W. (1994). Dissociation and disturbances of self. In: D. Cicchetti & S. L. Toth (Eds.), Disorders and dysfunctions of the self, vol. 5 (pp. 251-265). Rochester, NY: University of Rochester Press; Putnam, F. W. (1995). Development of dissociative disorders. In: D. Chicchetti & D. J. Cohen (Eds.), Developmental psychopathology, vol. 2 (pp. 581-608). New York: Wiley], the experimental research using DID case studies and samples is reviewed. As a whole, research suggests that amnesic barriers between alter personalities are typically impervious to explicit stimuli, as well as conceptually driven implicit stimuli. Autobiographical memory deficits are also experimentally evident in DID. Although no experimental studies have addressed the issue of source amnesia or pseudomemories, there is some evidence that pseudomemories are an infrequent but real phenomenon in DID patients. Finally, potential deficits in working memory are outlined, including those relating to cognitive inhibition. Research directions are discussed throughout to further elucidate the nature of memory dysfunction in DID.

An Exploratory Analysis of Voice Hearing in Chronic PTSD: Potential Associated Mechanisms

This research investigated auditory hallucinations (AH) in a sample with chronic posttraumatic stress disorder (PTSD) and examined dissociation and thought suppression as potential associated mechanisms. In all, 40 individuals with PTSD were assessed on the hallucinations subscale of the Positive and Negative Syndrome Scale and on measures of dissociation and thought suppression. Half of the sample reported AH (n = 20, 50%). Those reporting AH had higher general and pathological dissociation scores but did not differ on thought suppression or PTSD symptom severity. Results suggest that (a) AH in chronic PTSD is not a rare phenomenon, (b) dissociation is significantly related to AH, and (c) dissociation may be a potential mediating mechanism for AH in PTSD.

Dissociative identity disorder: An empirical overview:

Objective: 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.

Complex trauma and intimate relationships: The impact of shame, guilt and dissociation

BACKGROUND This study examined dissociation, shame, guilt and intimate relationship difficulties in those with chronic and complex PTSD. Little is known about how these symptom clusters interplay within the complex PTSD constellation. Dissociation was examined as a principle organizing construct within complex PTSD. In addition, the impact of shame, guilt and dissociation on relationship difficulties was explored. METHODS Sixty five treatment-receiving adults attending a Northern Irish service for conflict-related trauma were assessed on measures of dissociation, state and trait shame, behavioral responses to shame, state and trait guilt, complex PTSD symptom severity and relationship difficulties. RESULTS Ninety five percent (n=62) of participants scored above cut-off for complex PTSD. Those with clinical levels of dissociation (n=27) were significantly higher on complex PTSD symptom severity, state and trait shame, state guilt, withdrawal in response to shame and relationship preoccupation than subclinical dissociators (n=38). Dissociation and state and trait shame predicted complex PTSD. Fear of relationships was predicted by dissociation, complex PTSD and avoidance in response to shame, while complex PTSD predicted relationship anxiety and relationship depression. LIMITATIONS The study was limited to a relatively homogeneous sample of individuals with chronic and complex PTSD drawn from a single service. CONCLUSIONS Complex PTSD has significant consequences for intimate relationships, and dissociation makes an independent contribution to these difficulties. Dissociation also has an organizing effect on complex PTSD symptoms.

Psychological Distress Following the 2010 Christchurch Earthquake: A Community Assessment of Two Differentially Affected Suburbs

This study aimed to explore posttraumatic distress and the cognitive variables of controllability and predictability in two demographically matched communities differentially affected by the Christchurch earthquake of September 4, 2010 (N = 124). A door-to-door survey was conducted 8–10 weeks after the initial quake. The two communities did not differ on acute stress disorder or symptoms, but the affected community had higher depression and anxiety scores. Depression, feeling on edge, and anxiety scores predicted acute stress symptoms. Uncontrollability of response to aftershocks predicted acute stress, depression, and anxiety symptoms. Results are discussed with reference to the impact of ongoing aftershocks and how they are likely to maintain a sense that responses to them are uncontrollable, which in turn maintains psychological distress.