Effects of a dissociative drug on fronto-limbic resting-state functional connectivity in individuals with posttraumatic stress disorder: a randomized controlled pilot study

How-To Study Dissociative Symptoms in a Broad Range of Mental Disorders: A Methodological Primer

Dissociative symptoms constitute a transdiagnostic phenomenon not only characterizing dissociative disorders but also occurring across a broad range of other mental disorders such as posttraumatic stress disorder or borderline personality disorder. In the latter disorders, dissociative symptoms such as depersonalization, derealization, or gaps in awareness significantly burden patients' wellbeing and functioning. Many efforts have been undertaken to better understand these debilitating symptoms. However, empirical findings have not yet converged in many areas (e.g., considering neurobiological correlates or effects of dissociative psychopathology on treatment outcome), which might partially be due to the heterogeneity and limitations of employed methodology. Here, we critically review the current state-of-the-art methodology in dissociation research, comparing methods to assess dissociative symptoms, provoke dissociative symptoms in the laboratory, select the participant sample, and consider critical sample characteristics. Discussing the informative value and limits of various standard and novel methodological approaches, we aim to provide information and nuanced guidance for future research. By these means, we aim to raise and harmonize standards in dissociation research and enable researchers of all career stages to enter, navigate, and make a significant and lasting contribution to research on dissociative symptoms in a broad range of mental disorders, ultimately contributing to a better understanding of dissociative psychopathology.

Neuroimaging of posttraumatic stress disorder in adults and youth: progress over the last decade on three leading questions of the field

Almost three decades have passed since the first posttraumatic stress disorder (PTSD) neuroimaging study was published. Since then, the field of clinical neuroscience has made advancements in understanding the neural correlates of PTSD to create more efficacious treatment strategies. While gold-standard psychotherapy options are available, many patients do not respond to them, prematurely drop out, or never initiate treatment. Therefore, elucidating the neurobiological mechanisms that define the disorder can help guide clinician decision-making and develop individualized mechanisms-based treatment options. To this end, this narrative review highlights progress made in the last decade in adult and youth samples on three outstanding questions in PTSD research: (1) Which neural alterations serve as predisposing (pre-exposure) risk factors for PTSD development, and which are acquired (post-exposure) alterations? (2) Which neural alterations can predict treatment outcomes and define clinical improvement? and (3) Can neuroimaging measures be used to define brain-based biotypes of PTSD? While the studies highlighted in this review have made progress in answering the three questions, the field still has much to do before implementing these findings into clinical practice. Overall, to better answer these questions, we suggest that future neuroimaging studies of PTSD should (A) utilize prospective longitudinal designs, collecting brain measures before experiencing trauma and at multiple follow-up time points post-trauma, taking advantage of multi-site collaborations/consortiums; (B) collect two scans to explore changes in brain alterations from pre-to-post treatment and compare changes in neural activation between treatment groups, including longitudinal follow up assessments; and (C) replicate brain-based biotypes of PTSD. By synthesizing recent findings, this narrative review will pave the way for personalized treatment approaches grounded in neurobiological evidence.