The Treatment of Depersonalization-Derealization Disorder: A Systematic Review.

Depersonalization-derealization disorder (DPD) is characterized by persistent or recurrent experiences of detachment from oneself and surroundings, as well as a sense of unreality. Considering the inadequacy of current research on treatment, we performed a systematic review of the available pharmacotherapies, neuromodulations, and psychotherapies for DPD. The systematic review protocol was based on PRISMA 2020 guidelines and pre-registered. The PubMed, Web of Science, PsycINFO, Embase, the Cochrane Library, Scopus, and ScienceDirect databases were searched from inception to June 2021. All treatments for DPD and all study types, including controlled and observational studies as well as case reports, were assessed. Of the identified 17,540 studies, 41 studies (four randomized controlled trials, one non-randomized controlled trial, 10 case series, and 26 case reports) involving 300 participants met the eligibility criteria. We identified 30 methods that have been applied independently or in combination to treat DPD since 1955. The quality of these studies was considered. The relationship between individual differences, such as symptoms, comorbidities, history, and duration since onset, and treatment effects was explored. The results suggest that a series of treatments, such as pharmacotherapies, neuromodulation, and psychotherapies, could be considered in combination. However, the quality and quantity of studies were generally low considering the high prevalence of DPD. The review concludes with suggestions for future research and an urgent call for more high-quality research.

The Detection of Invalid Responses Using the Dissociative Experiences Scale-V (DES-V).

The Dissociative Experiences Scale (DES) is the most widely used self-report measure of dissociation but lacks a validity scale. Abu-Rus et al. (2020) created the DES-V by embedding atypical and inconsistency items in the DES, ultimately concluding that atypicality demonstrated the greatest ability to differentiate honest respondents from feigners. Among their study limitations, Abu-Rus et al. noted the homogeneous nature of their clinical group (i.e., largely comprising individuals with PTSD) and the potential need to refine the existing atypicality items for a more heterogenous dissociation population. The current study aimed to refine the DES-V by enlisting dissociation experts to improve the believability of the atypical items (while simultaneously ensuring they did not betoken any actual dissociative symptomology) and by supplementing the online sample with a clinical sample that included a broad range of dissociative disorders. Data cleaning comprised eight different techniques, to better ensure the validity of the online sample. Honest and Feigning groups completed the assessments through Amazon's Mechanical Turk; the clinical dissociative disorder group completed hard copy versions. The atypicality scale discriminated the three groups well, with the Feigning group scoring significantly higher than both of the honest groups (online and clinical). The mean atypicality scores of the two honest groups did not differ significantly. In addition, the scale incremented over the original DES-V in a logistic regression predicting honest and feigning participants. These robust results suggest that the revised DES-V could provide researchers with a valuable tool for validating online samples with greater precision - an increasingly vital need in light of the growing reliance on online samples.

Trauma, Emotional Regulation, and Coping Styles in Individuals with and without Probable Dissociative Disorders in Hong Kong.

Previous studies showed that dissociation and dissociative disorders (DDs) are prevalent and are associated with considerable individual and social consequences. There are ongoing debates regarding whether dissociation is a response to betrayal trauma across cultures and whether dissociation can be explained by maladaptive coping. Additionally, little is known about the clinical features of individuals with DDs in the Chinese context. This study aimed to investigate the relationship between trauma, emotional regulation, coping, and dissociation. We analyzed baseline data from a randomized controlled trial (N = 101). Participants with dissociative symptoms in Hong Kong completed self-report assessments. Structured interviews were also conducted subsequently. Participants with probable DDs reported more traumatic events (p = .009 to .017) and exhibited significantly higher levels of dysfunctional coping (p < .001) compared to those who reported dissociative symptoms but did not have a DD. Dissociative symptoms were more strongly associated with betrayal trauma than with non-betrayal trauma. Among different emotion regulation and coping strategies, dysfunctional coping was the only significant factor associated with dissociative symptoms (ß = .309, p = .003). Dysfunctional coping was a statistically significant mediator that may explain the relationship between betrayal trauma and dissociative symptoms. Although other mediation paths are also possible and further longitudinal studies are required, our findings highlight the strong link between dysfunctional coping and dissociative symptoms and suggest that coping skills training should be incorporated into interventions for betrayal trauma survivors with dissociative symptoms. Additionally, this study provides evidence for the cross-cultural validity of the betrayal trauma theory. Further studies, however, are required.

A Preliminary Longitudinal Analysis of Symptom Management, Post-traumatic Stress, and Depressive Symptoms in Chinese Adults with Dissociative Symptoms.

People with dissociative symptoms are generally poly-symptomatic and require high levels of healthcare resources. Post-traumatic stress disorder (PTSD) and depressive symptoms are two major disabling comorbid symptoms in people with dissociative symptoms. While the sense of control over symptoms may be associated with PTSD and dissociative symptoms, the interplay among these factors over time remains unexplored. This study examined the predictors of PTSD and depressive symptoms in people with dissociative symptoms. Longitudinal data from 61 participants with dissociative symptoms were analyzed. Participants completed self-report measures of dissociative, depressive, and PTSD symptoms and the sense of control over symptoms two times (T1 & T2) with an interval of over one month. PTSD and depressive symptoms were not transient or time-specific, but they persisted over time in our sample. Hierarchical multiple regression analyses revealed that, after controlling for age, treatment usage and baseline symptom severity, T1 symptom management scores (ß = -.264, p = .006) negatively predicted T2 PTSD symptoms, while T1 PTSD symptoms (ß = .268, p = .017) positively predicted T2 depressive symptoms. T1 depressive symptoms (ß = -.087, p = .339) did not predict T2 PTSD symptoms. The findings highlight the importance of improving symptom management skills and treating comorbid PTSD symptoms when working with people with dissociative symptoms.

Advancing Research on and Treatment of Dissociative Identity Disorder With People With Lived Experience.

Dissociative identity disorder is a posttraumatic, psychobiological syndrome that develops over time during childhood. Despite empirical evidence supporting the validity of this diagnosis and its relation to trauma, the disorder remains a misunderstood and stigmatized condition. This article highlights expert consensus guidelines and current empirical research on the treatment of dissociative identity disorder. In addition, the authors describe the Lived Experience Advisory Panel (LEAP), which was designed to leverage the expertise of individuals with dissociative identity disorder to combat stigma and improve research, clinical programming, professional education, and public outreach related to the disorder. This article also describes how LEAP members have partnered with other researchers to create new knowledge through participatory action research in order to advance equitable service provision and effect positive change.

Nocturnal agitation: From sleep state dissociation to sleep-related dissociative state.

Nocturnal agitation refers to a broad spectrum of symptoms from simple movements to aggressive behaviors with partial or complete loss of awareness. An accurate identification of its etiology is critical for appropriate therapeutic intervention. In children and young adults, distinguishing between non-rapid eye movement (NREM) sleep parasomnias and psychogenic non-parasomniac manifestations, a condition known as sleep-related dissociative disorder (SRDD), can be challenging. This review aims to summarize current clinical, neurophysiological, and epidemiological knowledge on NREM parasomnia and SRDD, and to present the pathophysiological hypotheses underlying these nocturnal manifestations. Sleepwalking, sleep terror and confusional arousals are the three main presentations of NREM parasomnias and share common clinical characteristics. Parasomniac episodes generally occur 30minutes to three hours after sleep-onset, they are usually short, lasting no more than few minutes and involve non-stereotyped, clumsy behaviors with frequent amnesia. The prevalence of NREM parasomnia decreases from 15-30% in children to 2-4% in adults. Parasomniac episodes are incomplete awakening from the deepest NREM sleep and are characterized by a dissociated brain activity, with a wake-like activation in motor and limbic structures and a preserved sleep in the fronto-parietal regions. SRDD is a less known condition characterized by dramatic, often very long episodes with frequent aggressive and potentially dangerous behaviors. SRDD episodes frequently occur in quiet wakefulness before falling asleep. These dissociative manifestations are frequently observed in the context of psychological trauma. The pathophysiology of SRDD is poorly understood but could involve transient changes in brain connectivity due to labile sleep-wake boundaries in predisposed individuals. We hypothesize that SRDD and NREM parasomnia are forms of sleep-related dissociative states favored by a sleep-wake state dissociation during sleep-onset and awakening process, respectively.

The lived experience of psychiatric-mental health nurses working with dissociative disorder inpatients: A phenomenological inquiry.

Nursing literature about dissociative disorders is lacking, resulting in a deficit of available evidence to drive nursing practice. This study sought to address this scarcity of literature by shedding light on the lived experiences of nurses who directly care or have cared for this population. Participants were individually interviewed along the lines of training, education, and personal experiences, and responses were analyzed to uncover themes found in multiple interviews. The result was a clear emphasis on improving education about the unique needs of individuals with dissociative disorders in order to improve the nursing care of this population.

Personality disorder traits, maladaptive schemas, modes and coping styles in participants with complex dissociative disorders, borderline personality disorder and avoidant personality disorder.

OBJECTIVE: The schema mode model offers a new conceptualisation of complex dissociative disorders (CDD) as it explains shifts between identities as shifts between schema modes. Furthermore, in this model CDD is conceived as personality pathology, incorporating core features of personality disorders. This study tested the assumptions of this schema mode model of CDD. METHOD: Questionnaires measuring personality disorder traits, schemas, schema modes and coping styles were filled out by patients with CDD, borderline personality disorder and avoidant personality disorder (N = 210), and their scores on the various constructs were compared. RESULTS: Participants with CDD were characterised by specific schizoid, schizotypal, borderline and avoidant personality traits and early maladaptive schemas in the domains of disconnection and rejection and over-vigilance and inhibition. The most pronounced schema modes were the dysfunctional parent modes, avoidant coping modes and the vulnerable child mode. For coping styles, no differences were found between the diagnostic groups. CONCLUSION AND DISCUSSION: On all outcome measures participants with CDD scored at the level of personality disorders and showed a unique pattern different from participants with borderline and avoidant personality disorder. This suggests that CDD shows features akin to a personality disorder. A clinical implication is that an adapted form of schema therapy might present a viable treatment option for CDD.

Dissociation-Induced Shame in Those with a Dissociative Disorder: Assessing the Impact of Relationship context using Vignettes.

Some evidence in non-clinical groups suggests that the relationship context in which dissociation is experienced might moderate its association with shame. The current study used vignettes detailing either dissociative symptoms or the expression of sadness occurring in three different relationship contexts: with a friend, an acquaintance, or when alone. Ratings of emotional (e.g. shame, anxiety) and behavioral (e.g. leave, talk) reactions were made on single-item measures, and shame feelings were further assessed with the State Shame Scale. Participants were in treatment for either dissociative identity disorder (n = 31) or other specified dissociative disorder (n = 3; N = 34). Feelings of shame were elevated in the acquaintance condition compared to when with a close friend or alone regardless of whether dissociation or sadness was experienced. In the acquaintance context, participants exposed to dissociation or sadness reported feeling annoyed at themselves, having a greater desire to leave, and a lesser desire to talk compared to when these experiences happened with a close friend or alone. Results suggest those with a dissociative disorder appraise themselves as more vulnerable to shame if experiencing dissociation or sadness when with an acquaintance, potentially because the risk of not being understood and rejected is heightened.

Psychometric evaluation of the Hong Kong Chinese version of the Dissociative Experiences Measure, Oxford (HKC-DEMO).

The Dissociative Experiences Measure, Oxford (DEMO) is a recently developed measure that reflects the current conceptualization of dissociation. However, psychometric investigations of the DEMO are still limited. The current study examined the factor structure and psychometric properties of the Hong Kong Chinese version of the DEMO (HKC-DEMO). Online survey data on 914 community-dwelling adults in Hong Kong was extracted from a primary preregistered study on sleep and dissociation. Confirmatory factor analyses revealed that a five-factor structure, identified as "unreality," "numbness and disconnectedness," "memory blanks," "zoned out," and "vivid internal world," fit the data adequately. The five-factor structure fit significantly better than a four-factor structure, which combined "zoned out" and "vivid internal world" as a single factor of "absorption." Furthermore, the HKC-DEMO demonstrated excellent reliability, and satisfactory convergent, and divergent validity. The current study was the first to translate the DEMO to other language and showed that the HKC-DEMO is reliable and valid for use in Hong Kong Chinese adults. Further validation of the HKC-DEMO with a clinical sample and samples with a wider age range would enhance the generalizability of the HKC-DEMO.

The Prevalence of Depersonalization-Derealization Disorder: A Systematic Review.

Depersonalization-Derealization disorder (DDD) is a psychiatric condition characterized by persistent feelings of detachment from one's self and of unreality about the outside world. This review aims to examine the prevalence of DDD amongst different populations. A systematic review protocol was developed before literature searching. Original articles were drawn from three electronic databases and included only studies where prevalence rates of DDD were assessed by standardized diagnostic tools. A narrative synthesis was conducted. Twenty-three papers were identified and categorized into three groups of participants: general population, mixed in/outpatient samples, and patients with specific disorders. The prevalence rates ranged from 0% to 1.9% amongst the general population, 5-20% in outpatients and 17.5-41.9% in inpatients. In studies of patients with specific disorders, prevalence rates varied: 1.8-5.9% (substance abuse), 3.3-20.2% (anxiety), 3.7-20.4% (other dissociative disorders), 16.3% (schizophrenia), 17% (borderline personality disorder), ~50% (depression). The highest rates were found in people who experienced interpersonal abuse (25-53.8%). The prevalence rate of DDD is around 1% in the general population, consistent with previous findings. DDD is more prevalent amongst adolescents and young adults as well as in patients with mental disorders. There is also a possible relationship between interpersonal abuse and DDD, which merits further research.

Depersonalization Disorder: Directed Forgetting as a Function of Emotionality.

There exists some evidence for a link between dissociation and emotionally avoidant information processing, yet studies to date have been contradictory. Our goal was to investigate emotionally avoidant processing in Depersonalization Disorder (DDD) using a directed forgetting (DF) paradigm. Thirty-two participants with DSM-IV DDD and 40 healthy controls performed an item-method DF task using positive, negative, and neutral words. Participants were also administered the Dissociative Experiences Scale (DES) and the Childhood Trauma Questionnaire (CTQ). The DDD group demonstrated significantly lower directed forgetting for negative, but not positive or neutral, words compared to controls. In the combined sample, DES total, depersonalization/derealization, and amnesia scores significantly inversely predicted explicit cued recall for to-be-forgotten negative words (higher dissociation, lower forgetting), while the CTQ was not predictive. The findings do not support emotionally avoidant processing in this paradigm; rather, DDD may be characterized by a diminished capacity to actively control attention and direct it away from emotionally disturbing material when instructed to do so.

Attention and Memory in Depersonalization-Spectrum Dissociative Disorders: Impact of Selective-Divided Attentional Condition, Stimulus Emotionality, and Stress.

We investigated cognition in depersonalization-spectrum dissociative disorders without comorbid posttraumatic stress disorder to explore evidence for emotionally avoidant information processing. Forty-eight participants with DSM-IV dissociative disorder (DD) (Depersonalization Disorder - 37, Dissociative Disorder NOS -11), 36 participants with Posttraumatic Stress Disorder (PTSD), and 56 healthy controls (HC) were administered the Weschler Adult Intelligence Scale-III (WAIS); the Weschler Memory Scale-III (WMS); and three Stroop tasks: the Standard Stroop, a selective-attention Emotional Stroop using neutral, dissociation, and trauma-related word categories, and a divided-attention Emotional Stroop using comparable words. Participants were also administered a paired-associates explicit and implicit memory test using emotionally neutral and negative words, before and after the Trier Social Stress Test. The DD and HC groups had comparable general intelligence and memory scores, though dissociation severity was inversely related to verbal comprehension and working memory. In the selective-attention condition, DD participants showed greater incidental recall across word categories with comparable interference. However in the divided-attention condition, DD participants significantly favored lesser attentional interference at the expense of remembering words. Across attentional conditions, DD participants had better recall for disorder-related than neutral words. Pre-stress, the DD group demonstrated better explicit memory for neutral versus negative words with reversal after stress, whereas the HC group demonstrated the opposite pattern; implicit memory did not differ. Cognition in the PTSD control group was generally dissimilar to the DD group. The findings in toto provide substantial evidence for emotionally avoidant information processing in DD, vulnerable to the impact of stress, at the level of both attention and memory.

Co-occurrence of severe PTSD, somatic symptoms and dissociation in a large sample of childhood trauma inpatients: a network analysis.

Co-occurrence of mental disorders including severe PTSD, somatic symptoms, and dissociation in the aftermath of trauma is common and sometimes associated with poor treatment outcomes. However, the interrelationships between these conditions at symptom level are not well understood. In the present study, we aimed to explore direct connections between PTSD, somatic symptoms, and dissociation to gain a deeper insight into the pathological processes underlying their comorbidity that can inform future treatment plans. In a sample of 655 adult inpatients with a diagnosis of severe PTSD following childhood abuse (85.6% female; mean age = 47.57), we assessed symptoms of PTSD, somatization, and dissociation. We analyzed the comorbidity structure using a partial correlation network with regularization. Mostly positive associations between symptoms characterized the network structure. Muscle or joint pain was among the most central symptoms. Physiological reactivation was central in the full network and together with concentrations problems acted as bridge between symptoms of PTSD and somatic symptoms. Headaches connected somatic symptoms with others and derealization connected dissociative symptoms with others in the network. Exposure to traumatic events has a severe and detrimental effect on mental and physical health and these consequences worsen each other trans-diagnostically on a symptom level. Strong connections between physiological reactivation and pain with other symptoms could inform treatment target prioritization. We recommend a dynamic, modular approach to treatment that should combine evidence-based interventions for PTSD and comorbid conditions which is informed by symptom prominence, readiness to address these symptoms and preference.

Group treatment for complex dissociative disorders: a randomized clinical trial.

BACKGROUND: Patients with complex dissociative disorders (CDD) report high levels of childhood- abuse experiences, clinical comorbidity, functional impairment, and treatment utilization. Although a few naturalistic studies indicate that these patients can benefit from psychotherapy, no randomized controlled trials have been reported with this patient-group. The current study evaluates a structured protocolled group treatment delivered in a naturalistic clinical setting to patients with CDD, as an add-on to individual treatment. METHODS: Fifty nine patients with CDD were randomized to 20 sessions of stabilizing group-treatment, conjoint with individual therapy, or individual therapy alone, in a delayed-treatment design. The treatment was based on the manual Coping with Trauma-Related Dissociation. The primary outcome was Global Assessment of Functioning (GAF), while secondary outcomes were PTSD and dissociative symptoms, general psychopathology, and interpersonal difficulties. RESULTS: Mixed effect models showed no condition x time interaction during the delayed treatment period, indicating no immediate differences between conditions in the primary outcome. Similar results were observed for secondary outcomes. Within-group effects were non-significant in both conditions from baseline to end of treatment, but significant improvements in psychosocial function, PTSD symptoms, and general psychopathology were observed over a 6-months follow-up period. CONCLUSION: In the first randomized controlled trial for the treatment of complex dissociative disorders, stabilizing group treatment did not produce immediate superior outcomes. Treatment was shown to be associated with improvements in psychological functioning. TRIAL REGISTRATION: Clinical Trials ( NCT02450617 ).

Dissociation and Dissociative Disorders Reconsidered: Beyond Sociocognitive and Trauma Models Toward a Transtheoretical Framework.

For more than 30 years, the posttraumatic model (PTM) and the sociocognitive model (SCM) of dissociation have vied for attention and empirical support. We contend that neither perspective provides a satisfactory account and that dissociation and dissociative disorders (e.g., depersonalization/derealization disorder, dissociative identity disorder) can be understood as failures of normally adaptive systems and functions. We argue for a more encompassing transdiagnostic and transtheoretical perspective that considers potentially interactive variables including sleep disturbances; impaired self-regulation and inhibition of negative cognitions and affects; hyperassociation and set shifts; and deficits in reality testing, source attributions, and metacognition. We present an overview of the field of dissociation, delineate uncontested and converging claims across perspectives, summarize key multivariable studies in support of our framework, and identifyempirical pathways for future research to advance our understanding of dissociation, including studies of highly adverse events and dissociation.

Pathological Dissociation in The National Comorbidity Survey Replication (NCS-R): Prevalence, Morbidity, Comorbidity, and Childhood Maltreatment.

Our aim was to examine U.S. national prevalence of pathological dissociation (PD) likely indicative of dissociative disorder, and associated morbidity, comorbidity, and childhood maltreatment. PD was assessed in 6,644 participants in the National Comorbidity Survey Replication, a nationally representative adult survey. Seven of the eight pathological dissociation taxon items were inquired about over the past month and scored on a 4-point scale. A conservative PD cutoff score was applied, with 100% specificity against healthy individuals and 84% sensitivity for Depersonalization Disorder which lies at the less severe end of the dissociative disorder spectrum; it yielded a national PD prevalence of 4.1%. The PD group had diminished physical and mental health, marked comorbidity with most major psychiatric disorders, and high likelihood of psychiatric hospitalization. Over half of PD members had attempted suicide, significantly more than individuals with lifetime major depression. Childhood maltreatment was quantified for physical abuse, witnessing domestic violence, physical neglect, emotional abuse, and emotional neglect. Total childhood trauma significantly positively predicted PD severity, as well as severity of all three pathological dissociative experiences (amnesia, depersonalization / derealization, identity alteration). Furthermore, each childhood trauma category significantly predicted PD severity uniquely and additively. Childhood maltreatment in the PD group was significantly greater than in lifetime major depression, except for similar emotional neglect, and was comparable to lifetime PTSD. The study reinforces the validity of prior PD findings across clinical and community samples, and highlights the need for increased attention toward diagnosing and treating these quite common and highly morbid disorders and their traumatic antecedents.

[Complex posttraumatic stress disorder in adults]. / Die Komplexe Posttraumatische Belastungsstörung im Erwachsenenalter.

The term "complex posttraumatic stress disorder" (cPTSD) appeared in the scientific literature 30 years ago and has now been included in a diagnostic catalogue for the first time, namely in the International Statistical Classification of Diseases and Related Health Problems 11 (ICD-11) which was officially published at the beginning of 2022. This usually severely debilitating disorder often poses great challenges to treating physicians and psychotherapists in everyday clinical practice. Due to the much-debated overlap of cPTSD with borderline personality disorder (BPD), which is very high in cases of comorbidity of BPD and PTSD, cPTSD became embroiled in scientific discussions about the raison d'être of BPD in the new dimensional concept of personality disorders (PD) in the ICD-11. In addition to a detailed explanation of the diagnostic criteria of cPTSD and their differentiation from other mental disorders, particularly from PTSD, BPD and dissociative disorders, this article summarizes the historical development of the concept of cPTSD to date and the currently available treatment options. The same criteria apply to cPTSD in childhood and adolescence as in adulthood, but there are some special features that are not addressed in this article.

Validating Dissociative Experience Scale (DES) in a Greek sample.

This study aimed to validate the Greek version of the Dissociative Experience Scale (DES). A sample of 340 psychiatric outpatients and controls was selected. Part of the sample went through a retest procedure after a two-week period. Due to the absence of equivalent tests, the Multiscale Dissociation Inventory (MDI), the Structured Clinical Interview for DSM-IV-Dissociative Disorders Revised (SCID-D-R), and the Zung Self-Rating Anxiety Scale were used. Explanatory factor analysis was performed, resulting in a 28-item scale; the analysis revealed four factors, explaining 61% of total variation: Depersonalization, Amnesia, Absorption, and Miscellaneous. Cronbach's alpha coefficient for the DES was 0.95. Intraclass correlation coefficient (ICC) of the total score between the first and second interview was 0.84. Concurrent and convergent validity, as assessed by correlations with clinical assessment used as a "gold standard," (0.77), MDI (0.96), and Zung scale (0.75) were satisfactory to excellent. The total score on the DES was significantly higher in the clinical sample than in the controls (17.8 ± 16.2 vs. 5.8 ± 7.2, p < .001), indicating high discriminant validity. After the ROC analysis was run, the best compromise between sensitivity/specificity was achieved at the value of 20. The Greek version of the DES is a reliable and valid tool suitable to assess dissociation in clinical and healthy populations.

Differentiating Dissociative from Non-Dissociative Disorders: A Meta-Analysis of the Structured Clinical Interview for DSM Dissociative Disorders (SCID-D).

Inaccurate diagnosis of dissociative disorders (DDs) remains a frequent problem. Misdiagnoses may lead to delayed or ineffective treatment, and subsequently poorer quality of life for those struggling with DDs, who frequently utilize mental health treatment and evidence high rates of self-harm and suicidality. This study's objective was to examine the magnitude of the effects with which the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D) and revised version (SCID-D-R) - henceforth referred to as the "SCID-D interviews" - provide diagnoses of DDs and differentiate them from nondissociative disorders as well as factitious and simulated dissociative presentations. For inclusion, studies had to be empirical investigations comparing SCID-D data of DD populations with other populations. Using combined methods of searching for "SCID-D" in electronic indexing databases, seeking recommendations from experts, and reviewing reference sections of identified studies, 15 studies were identified and subjected to meta-analytic review. Analyses showed that the overall SCID-D interview score (effect size 3.12) as well as each of the five subscales - particularly amnesia and identity alteration (effect sizes 2.16 and 2.87, respectively) - significantly differentiated DD from non-DD. Findings suggest that the SCID-D interviews show good validity identifying and differentiating those with DDs as compared to those without DDs. The SCID-D interviews are valid instruments for diagnosing and differentiating DD from other psychiatric disorders and feigned presentations of DD. Clinicians, researchers, and forensic experts can use the SCID-D interviews with confidence to make differential diagnoses of DDs. Future research using the SCID-D interviews is discussed.