Effects of acute cortisol administration on perceptual priming of trauma-related material

Wakefulness impairs selective consolidation of relevant trauma-associated memories resulting in more frequent intrusions

Recent studies show that sleep reduces intrusive memories after analog trauma. This effect is assumed to be caused by sleep's impact on memory consolidation. However, the underlying processes of this phenomenon have not been uncovered. Thus, the current study investigates the hypothesis that sleep reduces intrusive memories by supporting the selective consolidation of relevant memories. Seventy-five participants were exposed to traumatic picture stories before nocturnal sleep or wakefulness during daytime. Memory for relevant and irrelevant trauma-associated stimuli was assessed prior to and after the retention period. Consistent with the hypothesis, results demonstrate reduced memory loss for relevant as opposed to irrelevant trauma-associated stimuli after sleep but not after wakefulness. Moreover, an incremental retention benefit for relevant trauma-associated stimuli was negatively correlated with the number of intrusive trauma memories after wakefulness. These results suggest that lack of sleep impairs selective gating of relevant trauma-associated memories, thereby enhancing intrusion development after trauma.

Traumatic imagery following glucocorticoid administration in earthquake-related post-traumatic stress disorder: A preliminary functional magnetic resonance imaging study

OBJECTIVE

Post-traumatic stress disorder involves excessive retrieval of traumatic memories. Glucocorticoids impair declarative memory retrieval. This preliminary study examined the effect of acute hydrocortisone administration on brain activation in individuals with earthquake-related post-traumatic stress disorder compared with earthquake-exposed healthy individuals, during retrieval of traumatic memories.

METHOD

Participants exposed to earthquakes with (n = 11) and without post-traumatic stress disorder (n = 11) underwent two functional magnetic resonance imaging scans, 1-week apart, in a double-blind, placebo-controlled, counter-balanced design. On one occasion, they received oral hydrocortisone (20 mg), and on the other, placebo, 1 hour before scanning. Symptom provocation involved script-driven imagery (traumatic and neutral scripts) and measures of self-reported anxiety.

RESULTS

Arterial spin labelling showed that both post-traumatic stress disorder and trauma-exposed controls had significantly reduced cerebral blood flow in response to retrieval of traumatic versus neutral memories in the right hippocampus, parahippocampal gyrus, calcarine sulcus, middle and superior temporal gyrus, posterior cingulate, Heschl's gyrus, inferior parietal lobule, angular gyrus, middle occipital gyrus, supramarginal gyrus, lingual gyrus and cuneus, and the left prefrontal cortex. Hydrocortisone resulted in non-significant trends of increasing subjective distress and reduced regional cerebral blood flow in the left inferior frontal gyrus, left anterior cingulate gyrus, middle temporal gyrus, cerebellum, postcentral gyrus and right frontal pole, during the trauma script.

CONCLUSION

Findings do not fit with some aspects of the accepted neurocircuitry model of post-traumatic stress disorder, i.e., failure of the medial prefrontal cortex to quieten hyperresponsive amygdala activity, and the potential therapeutic benefits of hydrocortisone. They do, however, provide further evidence that exposure to earthquake trauma, regardless of whether post-traumatic stress disorder eventuates, impacts brain activity and highlights the importance of inclusion of trauma-exposed comparisons in studies of post-traumatic stress disorder.

Intrusive memories and voluntary memory of a trauma film: Differential effects of a cognitive interference task after encoding

Methods to reduce intrusive memories (e.g., of traumatic events) should ideally spare voluntary memory for the same event (e.g., to report on the event in court). Single-trace memory accounts assume that interfering with a trace should impact both its involuntary and voluntary expressions, whereas separate-trace accounts assume these two can dissociate, allowing for selective interference. This possibility was investigated in 3 experiments. Nonclinical participants viewed a trauma film followed by an interference task (Tetris game-play after reminder cues). Next, memory for the film was assessed with various measures. The interference task reduced the number of intrusive memories (diary-based, Experiments 1 and 2), but spared performance on well-matched measures of voluntary retrieval-free recall (Experiment 1) and recognition (Experiments 1 and 2)-challenging single-trace accounts. The interference task did not affect other measures of involuntary retrieval-perceptual priming (Experiment 1) or attentional bias (Experiment 2). However, the interference task did reduce the number of intrusive memories in a laboratory-based vigilance-intrusion task (Experiments 2 and 3), irrespective of concurrent working memory load during intrusion retrieval (Experiment 3). Collectively, results reveal a robust dissociation between intrusive and voluntary memories, having ruled out key methodological differences between how these two memory expressions are assessed, namely cue overlap (Experiment 1), attentional capture (Experiment 2), and retrieval load (Experiment 3). We argue that the inability of these retrieval factors to explain the selective interference is more compatible with separate-trace than single-trace accounts. Further theoretical developments are needed to account for this clinically important distinction between intrusive memories and their voluntary counterpart. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Intrusive memories of trauma: A target for research bridging cognitive science and its clinical application

Intrusive memories of a traumatic event can be distressing and disruptive, and comprise a core clinical feature of post-traumatic stress disorder (PTSD). Intrusive memories involve mental imagery-based impressions that intrude into mind involuntarily, and are emotional. Here we consider how recent advances in cognitive science have fueled our understanding of the development and possible treatment of intrusive memories of trauma. We conducted a systematic literature search in PubMed, selecting articles published from 2008 to 2018 that used the terms "trauma" AND ("intrusive memories" OR "involuntary memories") in their abstract or title. First, we discuss studies that investigated internal (neural, hormonal, psychophysiological, and cognitive) processes that contribute to intrusive memory development. Second, we discuss studies that targeted these processes using behavioural/pharmacological interventions to reduce intrusive memories. Third, we consider possible clinical implications of this work and highlight some emerging research avenues for treatment and prevention, supplemented by new data to examine some unanswered questions. In conclusion, we raise the possibility that intrusive memories comprise an alternative, possibly more focused, target in translational research endeavours, rather than only targeting overall symptoms of disorders such as PTSD. If so, relatively simple approaches could help to address the need for easy-to-deliver, widely-scalable trauma interventions.

Acute stress-induced cortisol elevation during memory consolidation enhances pattern separation

Stress is a potent modulator of brain function and particularly mnemonic processes. While chronic stress is associated with long-term deficits in memory, the effects of acute stress on mnemonic functions are less clear as previous reports have been inconsistent. Some studies suggest that cortisol, a stress hormone that modulates biological changes in response to stress, may enhance memory consolidation and impair memory retrieval. However, other studies report no effect of cortisol on either memory consolidation or retrieval. These discrepancies could be due to differences in the timing and sequencing of the experimental procedures or individual differences in participants’ stress response. In the present study, we examined the effect of increased cortisol levels due to acute stress, induced by the Trier Social Stress Test (TSST), on a pattern separation memory task while differentiating the distinct stages of memory processing and controlling for the effects of diurnal variation. Sixty-nine young adults completed a 2-d study in which subjects either underwent the TSST immediately following the encoding part of the memory task, targeting memory consolidation, or immediately prior to the recognition part of the memory task on the second day, targeting memory retrieval. Control subjects completed the same study procedures but underwent a control version of the TSST that did not induce a stress response. Mnemonic discrimination of highly similar stimuli was enhanced by stress induced during consolidation with better discrimination showing a significant correlation with increased cortisol responses. Stress induced during memory retrieval showed no significant effect on memory performance. These findings suggest that stress induced changes in cortisol differentially affect the consolidation and retrieval stages of memory function.

Differential effects of sleep on explicit and implicit memory for potential trauma reminders: findings from an analogue study

Background: Recent findings suggest that disruptions of sleep-related memory processing are involved in the development of posttraumatic stress symptoms. More specifically, exposure to an analogue traumatic event resulted in fewer intrusive memories, when it was followed by sleep instead of continued wakefulness. However, competing evidence suggests that sleep deprivation may reduce intrusive re-experiencing. To address these conflicting accounts, we examined how sleep - as opposed to partial sleep deprivation - modulates explicit and implicit trauma memory using an analogue procedure. Methods: Healthy participants (N = 41) were assigned to a Sleep or Partial sleep deprivation group. Prior to nocturnal sleep, both groups were exposed to "traumatic" picture stories. After sleep or partial sleep deprivation, participants were subjected to tests of explicit and implicit memory for potential trauma reminders. Thereafter, participants completed an intrusion triggering task that was embedded in a distractor task. Results: Analyses revealed higher explicit memory for potential trauma reminders after sleep as compared to partial sleep deprivation. No group differences were found for implicit memory. Participants responded with fewer intrusions after sleep than following partial sleep deprivation. Conclusions: The current findings support a protective role of sleep in trauma memory processing, which may be evident after the first night of sleep post-trauma. Although more research is needed, our results corroborate the importance of promoting restful sleep in trauma-exposed individuals.

Susceptibility to others' emotions moderates immediate self-reported and biological stress responses to witnessing trauma

BACKGROUND

The peri-traumatic stress response is a strong predictor of symptom development after trauma exposure. Regarding witnessing trauma, the stress response might depend on the susceptibility to others' emotions (emotional contagion, EC). This study investigated whether EC moderates the immediate stress response using a trauma film paradigm.

METHODS

Ninety-five healthy participants were randomly exposed to a trauma or a neutral film. Perceived stressfulness of the film and pre-to post-film changes in self-reported anxiety, heart rate and saliva cortisol levels were assessed. EC towards negative and positive emotions was measured using the emotional contagion scale and its emotion-specific subscales.

RESULTS

Overall, the trauma film was perceived as distressing and elicited an increase in self-reported anxiety, heart rate and saliva cortisol levels relative to the neutral film. EC towards negative emotions was positively related to the perceived stressfulness of the film, increased anxiety and increased heart rate. The association with saliva cortisol levels was also in the expected direction, but not statistically significant. These associations were not found for EC towards positive emotions.

DISCUSSION

EC towards negative emotions may be an important predictor of trauma exposure outcomes. Further research should clarify its specific contribution in witnessing and undergoing trauma.

From neuroscience to evidence based psychological treatments - The promise and the challenge, ECNP March 2016, Nice, France

This ECNP meeting was designed to build bridges between different constituencies of mental illness treatment researchers from a range of backgrounds with a specific focus on enhancing the development of novel, evidence based, psychological treatments. In particular we wished to explore the potential for basic neuroscience to support the development of more effective psychological treatments, just as this approach is starting to illuminate the actions of drugs. To fulfil this aim, a selection of clinical psychologists, psychiatrists and neuroscientists were invited to sit at the same table. The starting point of the meeting was the proposition that we know certain psychological treatments work, but we have only an approximate understanding of why they work. The first task in developing a coherent mental health science would therefore be to uncover the mechanisms (at all levels of analysis) of effective psychological treatments. Delineating these mechanisms, a task that will require input from both the clinic and the laboratory, will provide a key foundation for the rational optimisation of psychological treatments. As reviewed in this paper, the speakers at the meeting reviewed recent advances in the understanding of clinical and cognitive psychology, neuroscience, experimental psychopathology, and treatment delivery technology focussed primarily on anxiety disorders and depression. We started by asking three rhetorical questions: What has psychology done for treatment? What has technology done for psychology? What has neuroscience done for psychology? We then addressed how research in five broad research areas could inform the future development of better treatments: Attention, Conditioning, Compulsions and addiction, Emotional Memory, and Reward and emotional bias. Research in all these areas (and more) can be harnessed to neuroscience since psychological therapies are a learning process with a biological basis in the brain. Because current treatment approaches are not fully satisfactory, there is an imperative to understand why not. And when psychological therapies do work we need to understand why this is the case, and how we can improve them. We may be able to improve accessibility to treatment without understanding mechanisms. But for treatment innovation and improvement, mechanistic insights may actually help. Applying neuroscience in this way will become an additional mission for ECNP.

Attachment-Related Regulatory Processes Moderate the Impact of Adverse Childhood Experiences on Stress Reaction in Borderline Personality Disorder

In this study, the authors explored whether attachment insecurity moderates the effects of adverse childhood experiences on stress reactivity in the context of borderline personality disorder (BPD). Participants were 113 women (39 with BPD, 15 with some BPD criteria present, 59 without any BPD symptoms) who participated in the Trier Social Stress Test. Saliva samples were collected before and after the stressor and assayed for salivary alpha-amylase (sAA) and cortisol. Adverse childhood experiences were measured using the Childhood Trauma Questionnaire, and attachment by the Experiences in Close Relationships-Revised questionnaire. Results revealed that attachment avoidance and a combination of more adverse childhood experiences and attachment insecurity resulted in higher sAA levels and differences in reactivity to the stressor. Interactions between attachment anxiety and adverse childhood experiences were related to blunted cortisol reactivity. The results suggest that the influence of adverse childhood experiences on stress regulation in BPD may be moderated by attachment-related regulatory processes.

Repeated cortisol administration does not reduce intrusive memories - A double blind placebo controlled experimental study

PTSD is a severe mental disorder, which may develop after exposure to traumatic events and is characterized by intrusive memories. Intrusions are sudden brief sensory memories of the traumatic event, that cause immense distress and impairment in every day functioning. Thus, the reduction of intrusive memories is one of the main aims of PTSD therapy. Recently, the glucocorticoid cortisol has been proposed as a pharmacological option to reduce intrusive memories, because cortisol is known to have memory retrieval inhibiting effects. However, the research on the effects of cortisol administration on intrusive memories is not conclusive. The aim of the present study was to examine if repeated cortisol administration inhibits intrusions and recognition memory in an experimental study using the trauma film paradigm. In a randomized double-blind placebo controlled design participants were exposed to a traumatic film (known to induce intrusions in healthy participants) and received either a low dose of cortisol (20mg) or placebo on the three days following "trauma exposure". Intrusive memories were assessed with an Electronic Diary and an Intrusion Triggering Task. Furthermore, we assessed explicit memory for the traumatic film clip with a recognition test. Contrary to our predictions, the cortisol group did not report fewer intrusions than the placebo group nor did it show diminished performance on the recognition test. Our results show that sole cortisol administration after a traumatic experience cannot reduce intrusive re-experiencing.

An integrative model linking traumatization, cortisol dysregulation and posttraumatic stress disorder: Insight from recent hair cortisol findings

Abundant evidence suggests links between trauma exposure, altered secretion of the glucocorticoid cortisol and the development/maintenance of posttraumatic stress disorder (PTSD), albeit with some inconsistency in findings. Further insight into the complex relations underlying this process may be derived from an increasing number of studies using hair cortisol analysis, a novel assessment strategy assumed to retrospectively capture long-term integrated cortisol secretion. Here, we evaluate the utility of hair cortisol analysis as a method in trauma/PTSD research and review current findings in this context. We compare hair cortisol data on the complex links between trauma, cortisol dysregulation and PTSD against the main findings obtained using traditional cortisol assessment methods. Finally, we integrate these data into a model which proposes that traumatization leads to dose and time-dependent changes in long-term cortisol output (initial post-traumatic increase, subsequent chronic attenuation) and that such dysregulation may partly mediate the link between traumatic load and the risk of PTSD development upon additional trauma exposure ("building block effect").

Hair cortisol concentrations and cortisol stress reactivity predict PTSD symptom increase after trauma exposure during military deployment

BACKGROUND

Previous evidence on endocrine risk markers for posttraumatic stress disorder (PTSD) has been inconclusive. Here, we report results of the first prospective study to investigate whether long-term hair cortisol levels and experimentally-induced cortisol stress reactivity are predictive of the development of PTSD symptomatology in response to trauma during military deployment.

METHODS

Male soldiers were examined before deployment to Afghanistan and at a 12-month post-deployment follow-up using dimensional measures for psychopathological symptoms. The predictive value of baseline (i) hair cortisol concentrations (HCC, N=90) and (ii) salivary cortisol stress reactivity (measured by the Trier Social Stress Test, N=80) for the development of PTSD symptomatology after being exposed to new-onset traumatic events was analyzed.

RESULTS

Baseline cortisol activity significantly predicted PTSD symptom change from baseline to follow-up upon trauma exposure. Specifically, our results consistently revealed that lower HCC and lower cortisol stress reactivity were predictive of a greater increase in PTSD symptomatology in soldiers who had experienced new-onset traumatic events (explaining 5% and 10.3% of variance, respectively). Longitudinal analyses revealed an increase in HCC from baseline to follow-up and a trend for a negative relationship between HCC changes and the number of new-onset traumatic events. Additional pre-deployment analyses revealed that trauma history was reflected in lower HCC (at trend level) and that HCC were negatively related to stressful load.

CONCLUSIONS

Our data indicate that attenuated cortisol secretion is a risk marker for subsequent development of PTSD symptomatology upon trauma exposure. Future studies are needed to confirm our findings in other samples.