A pharmacological challenge paradigm to assess neural signatures of script-elicited acute dissociation in women with post-traumatic stress disorder.

BACKGROUND: There is limited experimentally controlled neuroimaging research available that could explain how dissociative states occur and which neurobiological changes are involved in acute post-traumatic dissociation. AIMS: To test the causal hypothesis that acute dissociation is triggered bottom-up by a selective noradrenergic-mediated increase in amygdala activation during the processing of autobiographical trauma memories. METHOD: Women with post-traumatic stress disorder (n = 47) and a history of interpersonal childhood trauma underwent a within-participant, placebo-controlled pharmacological challenge paradigm (4.0 mg reboxetine versus placebo) employing script-driven imagery (traumatic versus neutral autobiographical memory recall). Script-elicited brain activation patterns (measured via functional magnetic resonance imagery) were analysed by means of whole-brain analyses and a pre-registered region of interest (i.e. amygdala). RESULTS: Self-reported acute dissociation increased significantly during trauma (versus neutral) recall but did not differ between pharmacological conditions. The pharmacological manipulation was also unsuccessful in eliciting increased amygdala activation following script-driven imagery in the reboxetine (versus placebo) condition. In the reboxetine condition, trauma retrieval resulted in similar activation patterns as in the placebo condition (e.g. elevated brain activation in the middle occipital gyrus and supramarginal gyrus), albeit with different peaks. CONCLUSIONS: Current (null) findings cast doubt on the suggested role of the amygdala in subserving dissociative processing of trauma memories. Alternative pharmacological manipulation approaches (e.g. ketamine) and analysis techniques (e.g. event-related independent component analysis) might provide better insight into the spatiotemporal dynamics and network shifts involved in dissociative experiences and autobiographical trauma memory recall.

Trauma-related dissociation and the autonomic nervous system: a systematic literature review of psychophysiological correlates of dissociative experiencing in PTSD patients.

Background: Neurophysiological models link dissociation (e.g. feeling detached during or after a traumatic event) to hypoarousal. It is currently assumed that the initial passive reaction to a threat may coincide with a blunted autonomic response, which constitutes the dissociative subtype of post-traumatic stress disorder (PTSD). Objective: Within this systematic review we summarize research which evaluates autonomic nervous system activation (e.g. heart rate, blood pressure) and dissociation in PTSD patients to discern the validity of current neurophysiological models of trauma-related hypoarousal. Method: Of 553 screened articles, 28 studies (N = 1300 subjects) investigating the physiological response to stress provocation or trauma-related interventions were included in the final analysis. Results: No clear trend exists across all measured physiological markers in trauma-related dissociation. Extracted results are inconsistent, in part due to high heterogeneity in experimental methodology. Conclusion: The current review is unable to provide robust evidence that peri- and post-traumatic dissociation are associated with hypoarousal, questioning the validity of distinct psychophysiological profiles in PTSD.

Antecedentes: Los modelos neurofisiológicos vinculan la disociación (por ejemplo, la sensación de desapego durante o después de un evento traumático) con la hipoactivación. Actualmente se asume que la reacción pasiva inicial ante una amenaza puede coincidir con una respuesta autonómica embotada, lo que constituye el subtipo disociativo del trastorno de estrés postraumático (TEPT).Objetivo: En esta revisión sistemática resumimos las investigaciones que evalúan la activación del sistema nervioso autónomo (por ejemplo, la frecuencia cardíaca, la presión arterial) y la disociación en pacientes con TEPT para discernir la validez de los modelos neurofisiológicos actuales de la hipoactivación relacionada con el trauma.Método: De 553 artículos seleccionados, se incluyeron en el análisis final 28 estudios (N=1300 sujetos) que investigaban la respuesta fisiológica a la provocación del estrés o a las intervenciones relacionadas con el trauma.Resultados: No existe una tendencia clara en todos los marcadores fisiológicos medidos en la disociación relacionada con el trauma. Los resultados extraídos son inconsistentes, en parte debido a la alta heterogeneidad en la metodología experimental.Conclusión: La presente revisión no puede aportar pruebas sólidas de que la disociación peri y postraumática esté asociada a la hipoactivación, lo que cuestiona la validez de los distintos perfiles psicofisiológicos en el TEPT.

Altered frontal electroencephalography as a potential correlate of acute dissociation in dissociative disorders: novel findings from a mirror confrontation study.

People suffering from chronic dissociation often experience stress and detachment during self-perception. We tested 18 people with dissociative disorders not otherwise specified (DDNOS; compared with a matched sample of 18 healthy controls) undergoing a stress-inducing facial mirror confrontation paradigm, and measured acute dissociation and frontal electroencephalography (measured with a four-channel system) per experimental condition (e.g. confrontation with negative cognition). Linear mixed models indicated a significant group×time×condition effect, with DDNOS group depicting less electroencephalography power than healthy controls at the beginning of mirror confrontation combined with negative and positive cognition. This discrepancy - most prominent in the negative condition - diminished in the second minute. Correlational analyses depicted a positive association between initial electroencephalography power and acute dissociation in the DDNOS group. These preliminary findings may indicate altered neural processing in DDNOS, but require further investigation with more precise electroencephalography measures.

Neural correlates of acute post-traumatic dissociation: a functional neuroimaging script-driven imagery study.

BACKGROUND: Current neurobiological models of post-traumatic stress disorder (PTSD) assume excessive medial frontal activation and hypoactivation of cortico-limbic regions as neural markers of post-traumatic dissociation. Script-driven imagery is an established experimental paradigm that is used to study acute dissociative reactions during trauma exposure. However, there is a scarcity of experimental research investigating neural markers of dissociation; findings from existing script-driven neuroimaging studies are inconsistent and based on small sample sizes. AIMS: The current aim was to identify the neural correlates of acute post-traumatic dissociation by employing the script-driven imagery paradigm in combination with functional magnetic resonance imaging. METHOD: Functional neuroimaging data was acquired in 51 female patients with PTSD with a history of interpersonal childhood trauma. Blood-oxygen-level-dependent response during the traumatic (versus neutral) autobiographical memory recall was analysed, and the derived activation clusters were correlated with dissociation measures. RESULTS: During trauma recall, enhanced activation in the cerebellum, occipital gyri, supramarginal gyrus and amygdala was identified. None of the derived clusters correlated significantly with dissociative symptoms, although patients reported increased levels of acute dissociation following the paradigm. CONCLUSIONS: The present study is one of the largest functional magnetic resonance imaging investigations of dissociative neural biomarkers in patients with PTSD undergoing experimentally induced trauma confrontation to elicit symptom-specific brain reactivity. In light of the current reproducibility crisis prominent in neuroimaging research owing to costly and time-consuming data acquisition, the current (null) findings highlight the difficulty of extracting reliable neurobiological biomarkers for complex subjective experiences such as dissociation.

The Clinician-Administered Dissociative States Scale (CADSS): Validation of the German Version.

The Clinician-Administered Dissociative States Scale (CADSS) is a structured clinical interview to assess state dissociation rated by clinicians. The current study aimed to validate the German version of CADSS by comparing it to the established self-report measures for dissociation and exploring its underlying factor structure. Severity of within-session state dissociation was assessed directly following a standard psychotherapy session in a trauma-exposed patient sample (N= 105; 81.9% female). Internal consistency, convergent validity with other dissociation measures, and the factorial structure of the instrument were analyzed. The German version exhibited excellent internal consistency (Cronbach's α = .94) and correlated significantly with self-report measures of state dissociation (r = .86) and trait dissociation (r = .77) indicative of high convergent validity. Exploratory factor analysis revealed a three-factor solution with the factors (1) Depersonalization/Derealization, (2) Identity Confusion/Alteration, and (3) Amnesia. Results support the CADSS as a useful instrument to assess state dissociation, conceptualized as a multidimensional construct, in clinical practice.

Dissociation and insecure attachment as mediators of the relation between childhood emotional abuse and nonclinical paranoid traits.

Background: Research suggests dissociation and insecure attachment serve as explanatory mechanisms in the pathway from childhood trauma to paranoia. However, past work has not examined these mechanisms concurrently in nonclinical populations. Objective: The current study sought to examine dissociation and insecure attachment as parallel mediators of the association between childhood emotional abuse and paranoid traits. Furthermore, a serial mediation model with insecure attachment preceding dissociation in the explanatory pathway was explored. Methods: Eighty-nine nonclinically ascertained young adults were assessed for childhood emotional abuse, dissociation, attachment styles, and paranoid traits. Parallel and serial mediation models were tested. Results: The association of childhood emotional abuse with both interview-based and self-reported paranoid traits was significantly mediated by dissociation and preoccupied attachment. Fearful attachment was a significant mediator in the model for self-reported paranoid traits. No evidence for a serial mediation effect was found. Conclusions: The present findings extend support for dissociation and attachment insecurity as mechanisms underlying the link between childhood emotional maltreatment and paranoid traits. Longitudinal research is needed to inform whether insecure attachment contributes to dissociation along the pathways to paranoid traits.

Antecedentes: La investigación sugiere que la disociación y el apego inseguro sirven como mecanismos explicativos en el camino del trauma infantil a la paranoia. Sin embargo, trabajos anteriores no han examinado estos mecanismos concurrentemente en poblaciones no clínicas.Objetivo: El estudio actual buscó examinar la disociación y el apego inseguro como mediadores paralelos de la asociación entre el abuso emocional infantil y los rasgos paranoides. Además, se exploró un modelo de mediación en serie con apego inseguro como precedente de la disociación en la vía explicativa.Métodos: Ochenta y nueve adultos jóvenes no evaluados clínicamente fueron medidos en cuanto a abuso emocional infantil, disociación, estilos de apego y rasgos paranoides. Se probaron modelos de mediación en paralelo y en serie.Resultados: La asociación del abuso emocional infantil con rasgos paranoides tanto basados en entrevistas como auto-reporte fue mediada significativamente por la disociación y el apego preocupado. El apego temeroso fue un mediador significativo en el modelo de rasgos paranoides auto-reportados. No se encontró evidencia de mediación en serie.Conclusiones: Los presentes hallazgos apoyan a la disociación y la inseguridad del apego como mecanismos subyacentes a la asociación entre el maltrato emocional infantil y los rasgos paranoides. Una investigación longitudinal sería necesaria para explorar si el apego inseguro contribuye a la disociación en la vía del desarrollo de los rasgos paranoides.

Structural and functional brain alterations in psychiatric patients with dissociative experiences: A systematic review of magnetic resonance imaging studies.

INTRODUCTION: There is currently no general agreement on how to best conceptualize dissociative symptoms and whether they share similar neural underpinnings across dissociative disorders. Neuroimaging data could help elucidate these questions. OBJECTIVES: The objective of this review is to summarize empirical evidence for neural aberrations observed in patients suffering from dissociative symptoms. METHODS: A systematic literature review was conducted including patient cohorts diagnosed with primary dissociative disorders, post-traumatic stress disorder (PTSD), or borderline personality disorder. RESULTS: Results from MRI studies reporting structural (gray matter and white matter) and functional (during resting-state and task-related activation) brain aberrations were extracted and integrated. In total, 33 articles were included of which 10 pertained to voxel-based morphology, 2 to diffusion tensor imaging, 10 to resting-state fMRI, and 11 to task-related fMRI. Overall findings indicated aberrations spread across diverse brain regions, especially in the temporal and frontal cortices. Patients with dissociative identity disorder and with dissociative PTSD showed more overlap in brain activation than each group showed with depersonalization/derealization disorder. CONCLUSION: In conjunction, the results indicate that dissociative processing cannot be localized to a few distinctive brain regions but rather corresponds to differential neural signatures depending on the symptom constellation.

Schema modes mediate the effect of emotional abuse in childhood on the differential expression of personality disorders.

BACKGROUND: There is sound evidence that childhood maltreatment increases the likelihood of developing personality disorders (PDs). However, research on the possible mechanisms involved in the relationship between childhood maltreatment and PDs is scarce. One potential mediator of the maltreatment-PD relationship are schema modes, reflecting dynamic states of cognition, emotion, and behaviour. AIMS: The current study aimed to explore the mediating effect of schema modes on the association between childhood maltreatment and the expression of Cluster B (borderline and antisocial) and C (avoidant and dependent) PDs. METHOD: Within a mixed sample of N = 120 clinical PD patients and non-clinical participants, a multivariate path model including interview-assessed childhood maltreatment (emotional abuse, emotional neglect, sexual abuse, and physical abuse), schema modes (child, parent, coping and healthy modes), and borderline, antisocial, avoidant and dependent PDs was explored. RESULTS: The path model depicted five significant indirect links from emotional abuse on PDs via distinct schema modes. The impact of emotional abuse on borderline PD was mediated by child and coping modes, while parent modes mediated the link to antisocial PD. Healthy modes acted as a mediator on dependent and avoidant PDs. CONCLUSIONS: The results indicate emotional abuse as a main predictor of schema mode clusters and emphasize the mediating role of schema modes on the maltreatment-related pathways towards PDs. Therapeutic implications are discussed with a special focus on healthy modes.

Latent classes of DSM-5 acute stress disorder symptoms in children after single-incident trauma: findings from an international data archive.

Background: After a potentially traumatic event (PTE), children often show symptoms of acute stress disorder (ASD), which may evolve into posttraumatic stress (PTS) disorder. A growing body of literature has employed latent class analysis (LCA) to disentangle the complex structure underlying PTS symptomatology, distinguishing between homogeneous subgroups based on PTS presentations. So far, little is known about subgroups or classes of ASD reactions in trauma-exposed children. Objective: Our study aimed to identify latent classes of ASD symptoms in children exposed to a single-incident PTE and to identify predictors of class membership (gender, age, cultural background, parental education, trauma type, and trauma history). Method: A sample of 2287 children and adolescents (5-18 years) was derived from the Prospective studies of Acute Child Trauma and Recovery (PACT/R) Data Archive, an international archive including studies from the USA, UK, Australia, and Switzerland. LCA was used to determine distinct subgroups based on ASD symptoms. Predictors of class membership were examined using a three-step approach. Results: Our LCA yielded a three-class solution: low (42%), intermediate (43%) and high (15%) ASD symptom severity that differed in terms of impairment and number of endorsed ASD symptoms. Compared to the low symptoms class, children in the intermediate or high severity class were more likely to be of female gender, be younger of age, have parents who had not completed secondary education, and be exposed to a road traffic accident or interpersonal violence (vs. an unintentional injury). Conclusions: These findings provide new information on children at risk for ASD after single-incident trauma, based on a unique set of international data. Classifying children based on latent symptom profiles helps to identify target groups for prevention and intervention after exposure to a PTE.

Antecedentes: después de un evento potencialmente traumático (EPT), los niños a menudo muestran síntomas de trastorno de estrés agudo (TEA), el cual, puede evolucionar a un trastorno de estrés postraumático (TEPT). Un creciente cuerpo de literatura ha empleado el análisis de clase latente (LCA por sus siglas en ingles) para desenredar la compleja estructura subyacente a la sintomatología de TEPT, distinguiendo entre subgrupos homogéneos basados en presentaciones de TEPT. Hasta ahora, se sabe poco sobre los subgrupos o clases de reacciones TEA en niños expuestos a traumas.Objetivo: Nuestro estudio tuvo como objetivo identificar clases latentes de síntomas de TEA en niños expuestos a un solo incidente de EPT e identificar predictores de pertenencia a la clase (género, edad, antecedentes culturales, educación de los padres, tipo de trauma e historial de trauma).Método: se obtuvo una muestra de 2287 niños y adolescentes (5­18 años) de los estudios Prospectivos del Archivo de Datos de recuperación y Trauma Infantil agudo (PACT/R, en sus siglas en inglés), un archivo internacional que incluye estudios de Estados Unidos, Reino Unido, Australia y Suiza. Se utilizó LCA para determinar distintos subgrupos basados en los síntomas de TEA. Los predictores de pertenencia a la clase se examinaron mediante análisis de regresión logística ponderada.Resultados: Nuestro LCA arrojó una solución de tres clases: gravedad de los síntomas de TEA baja (42%), intermedia (43%) y alta (15%) que difería en términos de deterioro y número de síntomas de TEA atribuidos. En comparación con la clase baja e intermedia, los niños en la clase de gravedad alta tenían más probabilidades de ser de género femenino, de menor edad, tener padres que no habían completado la educación secundaria y estar expuestos a la violencia interpersonal (versus a eventos médicos no interpersonales). Pertenecer a una minoría étnica se asoció con la pertenencia a la clase de "síntomas intermedios" en comparación con la clase de "síntomas bajos".Conclusiones: Estos hallazgos brindan nueva información sobre los niños en riesgo de TEA después de un incidente traumático único, en base a un conjunto único de datos internacionales. La clasificación de los niños según los perfiles de síntomas latentes ayuda a identificar los grupos objetivo para la prevención e intervención después de la exposición a un EPT.