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.

Brain stimulation for patients with multiple sclerosis: an umbrella review of therapeutic efficacy

Multiple sclerosis patients often experience various symptoms that can greatly impact their quality of life. There are various brain stimulation techniques that have been evaluated for their ability to reduce the symptoms of multiple sclerosis. However, there is inconsistency in the specific stimulation methods used and the symptoms targeted in the existing research. This umbrella review conducted in order to evaluate the effectiveness of brain stimulation and identify limitations and gaps for further research. In this umbrella review, we conducted a searched on Web of Knowledge, PubMed, and Scopus database. We specifically looked for reviews, with or without meta-analyses, that have investigated the effects of brain stimulation methods on symptoms of multiple sclerosis. All articles were examined by AMSTAR 2 (A Measure Tool to Assess Systematic Review 2). We identified 155 articles, of which 14 were eligible for inclusion. Of those, five were qualitative studies and nine were meta-analyses. Among the included studies, four examined the use of deep brain stimulation, while ten investigated the therapeutic potential of noninvasive brain stimulation. Considering the heterogeneity of studies, the current evidence suggests that repetitive transcranial magnetic stimulation may be effective in treating pain and improving motor function, while transcranial direct current stimulation may be useful in alleviating fatigue and enhancing certain aspects of cognitive performance. Deep brain stimulation, on the other hand, appears to be effective in reducing tremors. However, further research is warranted to validate these findings and address the existing limitations in the field.

Effect of Relaxation-Based Virtual Reality on Psychological and Physiological Stress of Substance Abusers Under Detoxification: A Randomized Controlled Trial

INTRODUCTION

Substance abuse is a widespread problem, with high rates of treatment dropout. Stress plays a crucial role in this problem, so innovative interventions with stressed patients can assist them in completing treatment.

METHODS

This study is a randomized controlled trial with 60 participants who have substance abuse disorder undergoing detoxification at a residency facility in Tehran, Iran. Participants were randomly assigned to one of three groups: watching a 360° video of nature, a 360° video of a city environment, or no virtual experience. The intervention was performed only for one session. Psychological stress was measured using the Positive and Negative Affect Schedule and Perceived Stress Scale before and after the intervention. Physiological stress was assessed through respiratory rate, skin conductance, and heart rate recordings during the virtual reality (VR) experience. Data analysis was performed using R software (version 4.2).

RESULTS

Paired t-test results indicated significant psychological differences before and after virtual nature experiences, but not in the control and city groups. The repeated measure ANOVA showed a significant reduction in skin conductance (p < 0.01) and respiratory rate (p < 0.01) scores in the nature group.

CONCLUSION

The findings suggest that VR relaxation could be a potentially beneficial intervention for reducing stress in patients during detoxification.

Functional brain changes after alternative pharmacological interventions in posttraumatic stress disorder: A systematic review of clinical trials

BACKGROUND

Posttraumatic stress disorder (PTSD) is a complex and heterogeneous mental health condition that can develop after exposure to a traumatic event. Clinical trials have used alternative pharmacological agents to treat PTSD, but their associated neural correlates remain unclear. The present systematic review aims to summarize the changes in brain function associated with the use of these alternative pharmacological agents in PTSD.

METHODS

Clinical trials using functional magnetic resonance imaging, either at rest or during the performance of tasks, were included if they compared the effects of alternative pharmacological agents between PTSD patients and either trauma-exposed controls or never-exposed healthy controls.

RESULTS

Sixteen studies were included, of which 11 used intranasal oxytocin, 2 used hydrocortisone, and 3 used delta-9-tetrahydrocannabinol (THC). Oxytocin administration was associated with the normalization of functional connectivity between the ventromedial prefrontal cortex and amygdala as well as enhanced the function of brain regions specifically involved in emotion processing (e.g., amygdala), working memory (e.g., dorsolateral prefrontal cortex), and reward (e.g., putamen). Hydrocortisone did not influence brain function at rest or during the performance of an autobiographical memory task, whereas THC was associated with the reduction of the amygdala and increased medial prefrontal cortex activation.

CONCLUSIONS

This systematic review identified preliminary evidence for normalizing brain function after the use of alternative pharmacological agents. Importantly, sex-specific differences were noted, in particular when using oxytocin, that will require further investigation.

The Comparative Efficacy of Unified Transdiagnostic Protocol (UP) and Mindfulness-Based Stress Reduction Protocol (MBSR) on Emotion Regulation and Uncertainty Intolerance in Infertile Women Receiving IVF

Some emotional and social aspects of infertility affect the response of the infertile women to the treatment. The purpose of this study was to compare the efficacy of unified transdiagnostic protocol (UP) and mindfulness-based stress reduction protocol (MBSR) on emotion regulation and uncertainty intolerance in infertile women receiving IVF. Forty-five infertile women with symptoms of anxiety and depression were included in the study. They were randomly assigned in two intervention groups and one control group. The UP was performed for 10 sessions and MBSR was performed for eight sessions. All participants completed emotion regulation and uncertainty intolerance questionnaires at pre-test, post-test, and follow-up stages. Both interventions had a significant effect on increasing patients' emotion regulation (p ≤ 0.05), but only unified transdiagnostic protocol had a significant effect on intolerance of uncertainty (p ≤ 0.05). Findings show that UP and MBSR have increased emotion regulation. Also UP could reduce the rate of uncertainty intolerance.