Neural correlates of emotional reactivity and regulation in traumatized North Korean refugees

What happened matters: Trauma type and cumulative trauma exposure in refugee youth psychopathology

OBJECTIVE

Trauma exposure-a contributor to psychological risk for refugee youth-is typically assessed using cumulative indices; however, recent findings indicate that trauma type may better predict psychological outcomes. This study investigated the utility of two methods of classifying trauma exposure-cumulative trauma and exposure to specific types of trauma (i.e., trauma subtypes)-in predicting the severity of symptoms related to posttraumatic stress disorder (PTSD) and anxiety for refugee youth.

METHOD

96 Syrian and Iraqi youth resettled as refugees in the United States self-reported trauma exposure and psychological symptoms. Multiple regression was used to assess the variance in symptom severity explained by specific trauma subtypes (i.e., victimization, death threat, and accidental/injury) as compared to cumulative trauma scores.

RESULTS

Multiple regression models predicting PTSD revealed cumulative trauma (b = 0.07; p = .004) and death threat trauma (b = 0.16; p = .001) as significant predictors of PTSD symptom severity; notably, death threat trauma was the only subtype associated with PTSD and explained more variance than cumulative trauma scores (10.3% and 8.4%, respectively). Cumulative trauma, but no specific trauma subtype, was associated with anxiety (b = .03; p = .043); however, this relation did not survive correction for multiple comparisons.

CONCLUSION

Focused trauma assessment-particularly consideration of death threat trauma and cumulative trauma exposures-may be useful in evaluating the risk of PTSD symptoms in refugee youth, whereas symptoms related to anxiety may be driven by other factors. These findings can be leveraged toward focused identification of youth at highest risk for PTSD symptoms, to improve prevention and early intervention efforts. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Neural correlates and plasticity of explicit emotion regulation following the experience of trauma

Experiencing trauma or other adverse life events is highly prevalent and poses a significant risk for the development of mental disorders. Understanding the underlying mechanisms and neural processes involved in trauma processing is crucial for both prevention and targeting symptoms. Especially, difficulties in emotion regulation emerge as one key mechanism implicated in the development of conditions such as post-traumatic stress disorder (PTSD) following traumatic experiences. However, neural correlates of explicit emotion regulation among individuals who have undergone trauma have not received much attention. Understanding the neural basis of dysregulated emotion following trauma could reveal important details about how trauma interferes with emotional regulation systems, informing the development of more specific intervention approaches. Therefore, this mini review summarizes current research, and identifies relevant gaps in the literature and challenges for future studies. Specifically, it provides an overview of the neural dysregulation associated with explicit emotion regulation strategies such as reappraisal or suppression. Finally, it highlights promising findings from intervention studies targeting emotion regulation, such as trauma-focused exposure therapy and neurofeedback, indicating neural plasticity in individuals with traumatic experiences. Hereby, this review aims to bridge the gap between fundamental and intervention research and highlights future directions for translational research.

Does Trauma Change the Way Individuals with Post-Traumatic Stress Disorder (PTSD) Deal with Positive Stimuli?

INTRODUCTION

Post-Traumatic Stress Disorder (PTSD) is a highly prevalent disorder and a highly debilitating condition. Although current theories focused on depressed mood and intrusion as critical dimensions, the mechanism through which depression increases the risk of PTSD remains unclear. Research usually concentrates on the hyperactive negative valence system (NVS) (e.g., increased fear and threat responses), but some evidence suggests a significant role for the hypoactive positive valence system (PVS) (e.g., less neural activation towards rewards).

METHOD

The main aim of the present research was to investigate whether probable PTSD leads to a different evaluation of the implicit processing in a refugee's sample. Ratings of arousal, dominance, and valence from 60 International Affective Picture System (IAPS) pictures (positive, neutral, and negative) were collected from 42 individuals with probable PTSD, and a group of 26 trauma-exposed individuals (Mage = 28.49 years, SD = ±7.78).

RESULTS

ANOVA results revealed a main group effect (η2p = 0.379) on arousal, dominance, valence dimensions, and pictures' categories (η2p = 0.620), confirming evidence according to which PTSD origins a state of maladaptive hyperarousal and troubles the regulation of emotions, and not supporting the view that such difficulties arise only with negative stimuli. Participants with probable PTSD deemed negative stimuli as more threatening than they really are, reacting to unpleasant images with greater negative emotionality (i.e., enhanced arousal and lower valence ratings) compared with individuals without PTSD. Moreover, they rated positive stimuli as less pleasant. Furthermore, arousal ratings were negatively correlated with valence (r = -0.709, p < 0.01) indicating that pictures with high arousal (negative) were associated with lower valence.

DISCUSSION

Our findings supported evidence according to which PTSD caused a constant state of hyperarousal and difficulties in regulating emotions facing environmental stimuli. Positive stimuli are considered less pleasant, and this inhibits from completely benefiting from them.

CONCLUSION

Our study provides evidence for a differential and potentially complementary involvement of NVS and PVS in PTSD development. Intervention for PTSD may, thus, target both negative and positive valence processing.

Psychosocial and neurobiological aspects of the worldwide refugee crisis: From vulnerability to resilience

Anisman, H., Doubad, D., Asokumar, A. & Matheson, K. Psychosocial and neurobiological aspects of the worldwide refugee crisis: From vulnerability to resilience. NEUROSCI BIOBEHAV REV, XXXX. Immigration occurs between countries either to obtain employment, for family reunification or to escape violence and other life-threatening conditions. Refugees and asylum seekers are often obligated to overcome a uniquely challenging set of circumstances prior to and during migration. Settlement following immigration may pose yet another set of stressors related to acculturation to the host country, as well as financial insecurity, discrimination, language barriers, and social isolation. Here we discuss the multiple consequences of immigration experiences, focusing on the health disturbances that frequently develop in adults and children. Aside from the psychosocial influences, immigration-related challenges may cause hormonal, inflammatory immune, and microbiota changes that favor psychological and physical illnesses. Some biological alterations are subject to modification by epigenetic changes, which have implications for intergenerational trauma transmission, as might disruptions in parenting behaviors and family dysfunction. Despite the hardships experienced, many immigrants and their families exhibit positive psychological adjustment after resettlement. We provide information to diminish the impacts associated with immigration and offer strength-based approaches that may foster resilience.

Neuropsychological Consequences of Massive Trauma: Implications and Clinical Interventions

Traumatic events, especially massive trauma resulting from catastrophic incidents, wars, or severe abuse can elicit significant neuropsychological alterations, with profound implications for cognitive, emotional, and behavioral functioning. This mini-review delineates the primary neural changes post-trauma and underscores the importance of timely neuropsychological and clinical interventions. Specific brain regions, including the amygdala and prefrontal cortex, undergo physiological changes that can lead to memory impairments, attention deficits, and emotional disturbances. PTSD, a commonly diagnosed condition post-trauma, exemplifies the intricate relationship between trauma and memory processing. Furthermore, the concept of neuroplasticity, the brain's inherent ability to adapt and rewire, offers hope for recovery. Current clinical interventions, such as cognitive behavioral therapy, mindfulness practices, and biofeedback, leverage this neuroplastic potential to foster healing. The review underscores the vital importance of early intervention to mitigate long-term neuropsychological impacts, emphasizing the role of timely and targeted clinical interventions. The synthesis of this knowledge is crucial for clinicians, allowing for informed therapeutic approaches that holistically address both the physiological and psychological dimensions of trauma.

Adverse Life Experiences and Brain Function: A Meta-Analysis of Functional Magnetic Resonance Imaging Findings

Importance

Adverse life experiences have been proposed to contribute to diverse mental health problems through an association with corticolimbic functioning. Despite compelling evidence from animal models, findings from studies in humans have been mixed; activation likelihood estimation (ALE) meta-analyses have failed to identify a consistent association of adverse events with brain function.

Objective

To investigate the association of adversity exposure with altered brain reactivity using multilevel kernel density analyses (MKDA), a meta-analytic approach considered more robust than ALE to small sample sizes and methodological differences between studies.

Data Sources

Searches were conducted using PsycInfo, Medline, EMBASE, and Web of Science from inception through May 4, 2022. The following search term combinations were used for each database: trauma, posttraumatic stress disorder (PTSD), abuse, maltreatment, poverty, adversity, or stress; and functional magnetic resonance imaging (fMRI) or neuroimaging; and emotion, emotion regulation, memory, memory processing, inhibitory control, executive functioning, reward, or reward processing.

Study Selection

Task-based fMRI studies within 4 domains (emotion processing, memory processing, inhibitory control, and reward processing) that included a measure of adverse life experiences and whole-brain coordinate results reported in Talairach or Montreal Neurological Institute space were included. Conference abstracts, books, reviews, meta-analyses, opinions, animal studies, articles not in English, and studies with fewer than 5 participants were excluded.

Data Extraction and Synthesis

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guideline, 2 independent reviewers assessed abstracts and full-text articles for entry criteria. A third reviewer resolved conflicts and errors in data extraction. Data were pooled using a random-effects model and data analysis occurred from August to November 2022.

Main Outcomes and Measures

Peak activation x-axis (left-right), y-axis (posterior-anterior), and z-axis (inferior-superior) coordinates were extracted from all studies and submitted to MKDA meta-analyses.

Results

A total of 83 fMRI studies were included in the meta-analysis, yielding a combined sample of 5242 participants and 801 coordinates. Adversity exposure was associated with higher amygdala reactivity (familywise error rate corrected at P < .001; x-axis = 22; y-axis = -4; z-axis = -17) and lower prefrontal cortical reactivity (familywise error rate corrected at P < .001; x-axis = 10; y-axis = 60; z-axis = 10) across a range of task domains. These altered responses were only observed in studies that used adult participants and were clearest among those who had been exposed to severe threat and trauma.

Conclusions and Relevance

In this meta-analysis of fMRI studies of adversity exposure and brain function, prior adversity exposure was associated with altered adult brain reactivity to diverse challenges. These results might better identify how adversity diminishes the ability to cope with later stressors and produces enduring susceptibility to mental health problems.

Biological Psychiatry in Displaced Populations: What We Know, and What We Need to Begin to Learn

Conflict and climate change continue to displace millions of people, who experience unique trauma and stressors as they resettle in host countries. Both children and adults who are forcibly displaced, or choose to migrate, experience posttraumatic stress disorder, anxiety, depression, and other mental health conditions at higher rates than the general population. This may be attributed to severe, cumulative stress and trauma (largely interpersonal traumas); discrimination and harassment in host countries; and structural barriers to accessing and addressing mental health concerns, including clinician availability, language barriers, cultural differences, geographic accessibility, health care access, and stigma. Despite high exposure to and clinical impact of such experiences, and despite representing 1% of the world population, forcibly displaced people are underrepresented in neuroscientific research. The availability of such literature and research findings is significant in understanding the unique genetic and cultural aspects of trauma- and stress-related mental health, advocacy, reducing stigma, informing prevention, and treatment. The present work aimed to explore how the field of neuroscience can address mental health equity for individuals who have been uprooted in relation to land, with a focus on refugee populations. We offer practical suggestions on how to improve research in this area and narrow the gap in knowledge.

Shape analysis of the subcortical structures in North Korean refugees with post-traumatic stress disorder and major depressive disorder

BACKGROUND

Despite the growing number of refugees and their mental health issues, neurobiological mechanisms to explain clinical symptoms resulting from traumatic events, such as post-traumatic stress disorder (PTSD) or major depressive disorder (MDD), have not been extensively investigated. Research on the mental health of North Korean refugees (NKRs) who defected to South Korea for resettlement is still at an early stage but commonly reports structural and functional abnormalities in brain regions related to reward and motivational processing. The nucleus accumbens (NAc) and ventral pallidum (VP) are the major sites in subcortical structures that play key roles in reward and motivation.

METHODS

The present study examined subcortical structural abnormalities of 28 NKRs and age-, sex- matched South Korean Controls (SKCs) using shape analysis at the vertex level.

RESULTS

Among the 28 NKRs, 18 had psychiatric disorders, including PTSD and MDD. The NKRs showed significantly reduced volumes in the right NAc and bilateral VP compared to the SKRs. The volume of the right VP showed a significant negative correlation with current PTSD severity in the NKR group.

CONCLUSIONS

Our findings demonstrated that structural alterations of the NAc and VP may explain PTSD and MDD observed in the refugees and further suggest that the aftereffect of trauma, manifested as anhedonia and anxiety, may show chronically.