Dissociation between working memory performance and proactive interference control in post-traumatic stress disorder

Impact of alcohol use, combat exposure, and posttraumatic stress on verbal and visual working memory performance in post-9/11 veterans

OBJECTIVE

Posttraumatic stress disorder (PTSD) and alcohol use (AU) are highly prevalent and comorbid among post-9/11 U.S. military veterans. Both issues are associated with working memory (WM) deficits, but have rarely been studied concurrently in cognitive studies of post-9/11 veterans. They also have been measured inconsistently, with variable outcomes, in prior veteran studies despite their relevance to new intervention paradigms involving WM.

METHOD

The present study evaluated 52 post-9/11 veterans [predominantly male (94.2%); White (44.2%) or Black (36.5%); 50% being diagnosed with PTSD based on CAPS-5 results] with objectively verified valid neuropsychological test performance on measures of PTSD, AU, combat exposure, and verbal and visual WM.

RESULTS

PTSD was not associated with verbal or visual WM performances, whereas AU and combat exposure were significantly associated with poorer visual WM performances.

CONCLUSIONS

AU and prior combat exposure may influence visual WM performances in post-9/11 veterans, which is relevant to novel PTSD treatment paradigms. This sample was limited to mostly male and White or Black participants, and future studies should focus on sampling more heterogeneous groups of veterans with regard to sex and ethnicity. Improvements in specification/multimodal WM assessment are important for future research, as these may directly impact developing intervention efforts. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Narrative Review of the Complex Interaction between Pain and Trauma in Children: A Focus on Biological Memory, Preclinical Data, and Epigenetic Processes

The incidence and collective impact of early adverse experiences, trauma, and pain continue to increase. This underscores the urgent need for translational efforts between clinical and preclinical research to better understand the underlying mechanisms and develop effective therapeutic approaches. As our understanding of these issues improves from studies in children and adolescents, we can create more precise preclinical models and ultimately translate our findings back to clinical practice. A multidisciplinary approach is essential for addressing the complex and wide-ranging effects of these experiences on individuals and society. This narrative review aims to (1) define pain and trauma experiences in childhood and adolescents, (2) discuss the relationship between pain and trauma, (3) consider the role of biological memory, (4) decipher the relationship between pain and trauma using preclinical data, and (5) examine the role of the environment by introducing the importance of epigenetic processes. The ultimate scope is to better understand the wide-ranging effects of trauma, abuse, and chronic pain on children and adolescents, how they occur, and how to prevent or mitigate their effects and develop effective treatment strategies that address both the underlying causes and the associated physiological and psychological effects.

Proactive Interference in Posttraumatic Stress Disorder

Deficits in working memory (WM) have a role in maintaining posttraumatic stress disorder (PTSD) symptoms, including intrusions, which are a hallmark of PTSD symptomatology. As intrusions are distressing and uncontrollable, it is important to investigate whether PTSD is associated with altered control of proactive interference in WM. Moreover, it is important to consider both verbal and visual WM, as previous research has demonstrated a visual versus verbal dissociation in PTSD. Although previous studies have explored proactive interference in visual and verbal stimuli using a recent probe task, the stimuli used thus far have been non-trauma-related. Therefore, we aimed to investigate proactive interference in PTSD using trauma-related verbal and visual stimuli. Road traffic accident (RTA) survivors with (n = 60) and without PTSD (n = 30) completed a recent probe task to assess proactive interference of visual and verbal trauma-related material. Participants with PTSD displayed significantly more proactive interference than trauma-exposed controls for visual, η_p ² = .40, and verbal material, η_p ² = .10, indicating that proactive interference is significantly impaired in PTSD. This demonstrates that further research is warranted and highlights the possibility of considering proactive interference of trauma-related stimuli in therapeutic approaches.

Dysregulation of inflammation, neurobiology, and cognitive function in PTSD: an integrative review

Compelling evidence from animal and human research suggest a strong link between inflammation and posttraumatic stress disorder (PTSD). Furthermore, recent findings support compromised neurocognitive function as a key feature of PTSD, particularly with deficits in attention and processing speed, executive function, and memory. These cognitive domains are supported by brain structures and neural pathways that are disrupted in PTSD and which are implicated in fear learning and extinction processes. The disruption of these supporting structures potentially results from their interaction with inflammation. Thus, the converging evidence supports a model of inflammatory dysregulation and cognitive dysfunction as combined mechanisms underpinning PTSD symptomatology. In this review, we summarize evidence of dysregulated inflammation in PTSD and further explore how the neurobiological underpinnings of PTSD, in the context of fear learning and extinction acquisition and recall, may interact with inflammation. We then present evidence for cognitive dysfunction in PTSD, highlighting findings from human work. Potential therapeutic approaches utilizing novel pharmacological and behavioral interventions that target inflammation and cognition also are discussed.

Sleep, trauma, fantasy and cognition in dissociative identity disorder, post-traumatic stress disorder and healthy controls: a replication and extension study

Background: Two aetiology models for dissociative identity disorder (DID) have been proposed, namely a childhood Trauma Model and an iatrogenic or Fantasy model. A recent study indicated that sleep disturbances underlie dissociative symptomatology. Objective: Our current study aims to test whether this finding can be replicated in an independent sample and to investigate if this finding still holds after correcting for childhood and adult traumatization. An experimental working memory task is included to investigate how sleep disturbance, traumatization, dissociation, and fantasy proneness impact cognitive functioning. Methods: Three groups of participants were included - individuals with DID, individuals with post-traumatic stress disorder (PTSD), and matched healthy controls. Sleep disturbances were measured and compared between the groups along with measures of childhood and adult traumatization, psychoform and somatoform [psychological and somatic] dissociative symptoms, and fantasy proneness. Cognitive capacity was assessed using a working memory task. Results: When controlled for traumatic experiences, sleep disturbances did not predict dissociative symptoms. When controlled for sleep disturbance and fantasy proneness, childhood traumatization did predict dissociative symptoms. Psychoform dissociative symptoms correlated with traumatic experiences more than with fantasy proneness. Working memory performance was similar among the participating groups. Propensity to fantasy did not discriminate individuals with DID and PTSD, and was a weak predictor of dissociative symptoms. Conclusion: Whereas DID and PTSD are associated with sleep disturbances, these features do not statistically predict dissociative symptoms in these disorders when traumatic experiences are taken into account. Fantasy proneness is not excessive in DID and PTSD. Hence, we found no evidence that sleep disturbances, propensity to fantasy and abnormal working memory capacity explain dissociative symptoms in DID and PTSD. In sum, the relationship between sleep and dissociative symptoms disappeared when potentially traumatizing events were controlled for.

Akt dependent adult hippocampal neurogenesis regulates the behavioral improvement of treadmill running to mice model of post-traumatic stress disorder

Physical exercise is well-established paradigm for improving adult neurogenesis and brain functions. As considered as an alternative therapeutic strategy, treadmill running could reduce cognitive impairment and psychiatric abnormalities associating post-traumatic stress disorder (PTSD), which might associate with the promote effects to adult neurogenesis. In current study, we aimed to address how treadmill exercise benefit adult hippocampal neurogenesis in PTSD model and the underlying molecular mechanism related with Akt signaling. PTSD was induced by exposure to aggressor and treatments were conducted with different intensity of compulsory treadmill running. We observed treadmill running improved hippocampal neurogenesis including proliferation and neural differentiation of neural stem cells (NSCs). Moreover, behavioral tests showed treadmill could attenuate the cognitive deficit and depressive/anxiety like behaviors in correlating with PTSD model. Moreover, treadmill running recovered the Akt activity in hippocampus. Interrupting treadmill running administrated mice with Akt inhibitor GSK690693 resulted in the blocked the effects of treadmill running to hippocampal neurogenesis and behavioral improvement in PTSD mice model. In conclusion, treadmill running could mediate behavioral functions and improve hippocampal neurogenesis in PTSD model by regulating Akt signaling.

The Association of the Exposure to Work-Related Traumatic Events and Work Limitations among Firefighters: A Cross-Sectional Study

Many firefighters suffering from traumatic events while on duty participate in the work force. However, the impact of work-related traumatic events on work performance is unclear. To address this issue, we administered a work-related traumatic event experience survey, the health-related work limitations questionnaire, the Korea Depression Scale, and the World Health Organization quality of life assessment to firefighters from four cities in Korea. The health-related work limitations questionnaire measured limitations in their ability to perform three specific work demands-physical, psychosocial, and environmental. Of 685 firefighters enrolled in the study, 618 (90.2%) were included in the final analyses. Their mean age ± standard deviation (SD) was 41.1 ± 8.0 years and mean employment period ± SD was 163.0 ± 101.2 months. A large percentage of participants reported they had experienced work-related traumatic events. Among the firefighters, the total work limitation prevalence was 21.5%, 16.8% of them were limited in their abilities to perform physical work demands, 15.5% were limited in performing psychosocial work demands, and 13.8% were limited in their abilities to function without difficulty within the ambient work environment. Based on multivariable logistic regression, with having work-related traumatic event experience of a threat or injury to self, the odds ratio (OR) of having work limitations in physical (OR = 3.32, 95% CI = 1.17⁻9.41), psychosocial (OR = 3.05, 95% CI = 1.08⁻8.61), environmental (OR = 4.89, 95% CI = 1.66⁻14.40) work demands, and total work limitation (OR = 3.73, 95% CI = 1.44⁻9.68) increased significantly. With experiences of treating fatalities or injured patients, the OR of total work limitation increased significantly (OR = 2.07, 95% CI = 1.09⁻3.91). We demonstrated a relationship between the firefighters' exposure to work-related traumatic events and their work limitations. A professional care management system for firefighters to prevent and manage work-related traumatic events should be developed in order to protect and improve their performance ability.

Significant association between catechol-O-methyltransferase (COMT) Val158/108Met polymorphism and cognitive function in veterans with PTSD

Core features of posttraumatic stress disorder (PTSD) are cognitive disturbances. Enzyme catechol-O-methyltransferase (COMT) degrades dopamine primarily in prefrontal cortex. Its functional polymorphism, COMT Val^158/108Met, affects COMT activity and dopamine availability and is associated with disturbances in cognition. The hypothesis was that PTSD subjects will have worse working memory than healthy controls and that the carriers of the COMT Met allele will show better cognitive performance compared to Val/Val carriers in PTSD and controls subjects. The aim of this study was to assess the differences in cognitive functioning between PTSD and control subjects and to evaluate the association between COMT Val^158/108Met polymorphism and cognitive function determined using the Rey-Osterrieth complex figure (ROCF) copy, immediate and delayed test. The study included 323 male Caucasian participants of Croatian origin: 205 male combat veterans with PTSD and 118 control subjects. A significant association between the COMT Val^158/108Met and the ROCF immediate and delayed scores in veterans with PTSD was found. We confirmed, on ethnically homogenous groups of veterans with matched combat experience, that controls had higher ROCF immediate and delayed test scores than veterans with PTSD. In PTSD subjects, the Met carriers of the COMT Val^158/108Met performed better (i.e. had higher ROCF scores) than Val/Val homozygotes on both ROCF immediate recall and delayed recall test. Our results provide the first evidence that the presence of one or two Met alleles of the COMT Val^158/108Met might act as a protective variant in working memory tasks in combat exposed veterans with PTSD.