Frequency of Intrusions and Appraisal of Related Distress After Analogue Trauma: A Comparative Ecological Momentary Assessment Methods Study

Convergence of real-time and retrospective assessments: A systematic investigation of naturally occurring and experimentally induced intrusions

BACKGROUND AND OBJECTIVES

Ecological momentary assessment is a popular method for monitoring symptoms in real-time. Especially for fleeting experiences, such as intrusions, real-time assessments may be more accurate than retrospective estimates. However, there are concerns regarding reactivity effects associated with real-time assessments and, conversely, the reliance on bias-prone retrospective assessments in clinical science and practice. In this study we used a between-groups design to examine whether real-time intrusion assessments influence retrospective reports (aim 1). Then, we investigated whether real-time and retrospective assessments systematically differed within individuals (aim 2).

METHODS

Over two weeks, 150 non-clinical individuals provided weekly retrospective intrusion assessments, while the majority (n = 102) additionally reported their intrusions in real-time, via smartphones. We examined both naturally occurring intrusions, which individuals experience in their everyday lives, and intrusions related to a standardized stressor (i.e., Trier Social Stress Test), taking place halfway.

RESULTS

Using Bayesian statistics, we found that assessing intrusions in real-time did not convincingly affect retrospective reports, and there was no strong evidence that real-time and retrospective intrusion assessments differed. However, the evidence of absence was inconclusive for some measures. Real-time and retrospectively reported intrusion frequencies and distress were strongly associated with one another.

LIMITATIONS

Future research is advised to replicate these findings with larger samples, for other types of stressors, in clinical populations, and over extended assessment periods.

CONCLUSIONS

The general agreement between real-time and retrospective assessments of intrusions is encouraging, tentatively suggesting that researchers and clinicians can flexibly select the assessment method that best suits their objectives.

Neural processing of audiovisual and painful analogue trauma and its relationship with subsequent audiovisual and pain intrusions

Background: Posttraumatic stress disorder and medically unexplained pain frequently co-occur. While pain is common during traumatic events, the processing of pain during trauma and its relation to audiovisual and pain intrusions is poorly understood.Objective: Here we investigate neural activations during painful analogue trauma, focusing on areas that have been related to threat and pain processing, and how they predict intrusion formation. We also examine the moderating role of cumulative lifetime adversity.Methods: Sixty-five healthy women were assessed using functional magnetic resonance imaging. An analogue trauma was induced by an adaptation of the trauma-film paradigm extended by painful electrical stimulation in a 2 (film: aversive, neutral) x 2 (pain: pain, no-pain) design, followed by 7-day audiovisual and pain intrusion assessment using event-based ecological momentary assessment. Intrusions were fitted with Bayesian multilevel regression and a hurdle lognormal distribution.Results: Conjunction analysis confirmed a wide network including anterior insula (AI) and dorsal anterior cingulate cortex (dACC) being active both, during aversive films and pain. Pain resulted in activation in areas amongst posterior insula and deactivation in a network around ventromedial prefrontal cortex (VMPFC). Higher AI and dACC activity during aversive>neutral film predicted greater audiovisual intrusion probability over time and predicted greater audiovisual intrusion frequency particularly for participants with high lifetime adversity. Lower AI, dACC, hippocampus, and VMPFC activity during pain>no-pain predicted greater pain intrusion probability particularly for participants with high lifetime adversity. Weak regulatory VMPFC activation was associated with both increased audiovisual and pain intrusion frequency.Conclusions: Enhanced AI and dACC processing during aversive films, poor pain vs. no-pain discrimination in AI and dACC, as well as weak regulatory VMPFC processing may be driving factors for intrusion formation, particularly in combination with high lifetime adversity. Results shed light on a potential path for the etiology of PTSD and medically unexplained pain.

Hitting the Rewind Button: Imagining Analogue Trauma Memories in Reverse Reduces Distressing Intrusions

Background

Intrusive re-experiencing of trauma is a core symptom of posttraumatic stress disorder. Intrusive re-experiencing could potentially be reduced by 'rewinding', a new treatment approach assumed to take advantage of reconsolidation-updating by mentally replaying trauma fast-backward.

Methods

The present analogue study was the first to investigate 'rewinding' in a controlled laboratory setting. First, 115 healthy women watched a highly aversive film and were instructed to report film-related intrusions during the following week. Twenty-four hours after film-viewing, participants reporting at least one intrusion (N = 81) were randomly allocated to an intervention (fast-backward, or fast-forward as active control condition) or a passive control condition. Intervention groups reactivated their trauma memory, followed by mentally replaying the aversive film either fast-backward or fast-forward repeatedly.

Results

Results indicate that replaying trauma fast-backward reduced intrusion load (intrusion frequency weighted for intrusion distress) compared to the passive group, whereas replaying fast-forward did not. No above-threshold differences between fast-backward and fast-forward emerged.

Conclusion

Present findings strengthen the view that 'rewinding' could be a promising intervention to reduce intrusions.

When does imagery rescripting become a double-edged sword? - Investigating the risk of memory distortion through imagery rescripting in an online Trauma film study

Imagery Rescripting (ImRs) has proven effective in reducing involuntary emotional memories. However, it is unclear whether and when it may lead to reduced accuracy of voluntary memory. Although previous analogue studies suggest that ImRs does not pose a general risk regarding memory distortion, it can not be ruled out that ImRs could cause memory impairment under certain risk conditions. In our three-day online trauma film study we investigated in a healthy sample (N = 267) whether specific instructions during ImRs as typically provided in clinical practice (i.e., detailed imagery with a sensory focus) increase the risk of memory distortions. Additionally, we examined whether the completeness of the original memory moderates these instruction effects. Contrary to our expectations, a sensory focus during ImRs was associated with higher memory accuracy in a recognition task, independently of the quality of the original memory. These results extend previous findings by suggesting that ImRs does not even impair memory performance when the quality of the original memory is poor and when the production of sensory-rich images is specifically encouraged. Our results question current practices employed to assess witness statement credibility, which are partly based on concerns that trauma-focused interventions like ImRs undermine memory accuracy.

Examining the role of trait anxiety and attentional bias to negative information in intrusion vulnerability following an emotionally negative event

BACKGROUND AND OBJECTIVES

Research shows that individuals with heightened trait anxiety are more likely to experience intrusions; however, the mechanism that accounts for this relationship is unclear. Two alternative hypotheses were tested to determine the nature of the associations between trait anxiety, attentional bias to negative information, and intrusion vulnerability.

METHODS

Intrusions were elicited using the trauma film paradigm, and post-event attentional bias to negative information was assessed using the dot-probe task. Participants then completed a week-long intrusions diary.

RESULTS

Results showed that attentional bias to negative information mediated the effect of heightened trait anxiety on elevated intrusion frequency. It was also revealed that heightened trait anxiety was associated with elevated intrusion-related distress, though attentional bias to negative information did not mediate this relationship.

LIMITATIONS

Our sample was comprised of undergraduate students who were not selected based on a previous pathology. Replication in clinical samples is warranted.

CONCLUSIONS

These findings provide new insight regarding individual differences in the experience of intrusions and suggest that both the frequency and distress associated with intrusions could represent clinical targets.

Can placebos reduce intrusive memories?

After traumatic experiences, intrusive memories can flash back and evoke significant distress. Here, we investigated whether the frequency and severity of intrusions can be reduced by the provision of placebo. After the (online) exposure to the trauma-film paradigm, healthy participants (N = 112) received deceptive placebo (DP), open-label placebo (OLP), or no treatment. In the DP group, participants were led to believe to receive a dopamine-modulating drug, which was supposed to disrupt the consolidation of traumatic memories, although they in fact received the same placebo tablets as the OLP group for one week. The results show that the groups did not differ in the frequency of intrusive memories after one week. However, participants receiving OLP reported a significantly reduced intensity of intrusions as compared to DP. Across groups, negative expectations about the intensity and controllability of intrusions were associated with a higher frequency of intrusions, higher distress, higher burden, and more negative appraisal. The results suggest that expectations play an important role in the emergence of intrusive memories and that some of the disabling aspects of intrusive memories can be reduced by placebo. This may carry clinical potential because placebos are an accessible, cost-effective intervention to reduce the risk of intrusive memories.

Exam-related unwanted intrusive thoughts and related neutralizing behaviors: Analogues to obsessions and compulsions

Exam-related unwanted intrusive thoughts (UITs) and related neutralizing behaviors are common experiences among students. The present study investigated in what ways these UITs and behaviors are analogues to clinical obsessions and compulsions. Twenty-nine students completed three ecological momentary assessment surveys per day over 7 consecutive days, assessing the severity of exam-related UITs and related neutralizing behaviors, obsessive-compulsive (OC) symptoms, anxiety, distress, urge to neutralize, depressed mood, and stress in the week immediately before an exam period. Multilevel analysis demonstrated that the severity of exam-related UITs and related neutralizing behaviors was positively associated with OC symptoms, anxiety, distress, urge to neutralize, and stress but was not related to depressed mood. During the study period, the exam-related UITs occurred on average 7 times, and the related neutralizing behaviors on average 6 times. Overall, they were experienced with mild severity, low distress, and low urge to neutralize. Findings indicate that some aspects of exam-related UITs and related neutralizing behaviors (e.g., association with distress and urge to neutralize) might be analogous to OC symptoms but not all (e.g., no relation to depressed mood). We discuss how research on obsessive-compulsive disorder could benefit from considering exam-related UITs and related behaviors.

The independent roles of attentional engagement with, and disengagement from, negative information in intrusive re-experiencing of negative events

BACKGROUND AND OBJECTIVES

Intrusive re-experiencing of negative events represents a key vulnerability factor for Post-Traumatic Stress Disorder. Thus, delineating attentional mechanisms that might contribute to key facets of intrusive re-experiencing would be highly advantageous. The present study sought to evaluate the novel hypothesis that biased attentional engagement and disengagement differentially contribute to two central facets of intrusive re-experiencing, frequency and controllability, respectively.

METHODS

One hundred undergraduates were exposed to an acutely negative event, followed by completion of an attentional task that permitted the discrete assessment of biased attentional engagement with, and biased attentional disengagement from, negative vs. non-negative information. Intrusions concerning this negative event were assessed daily, for the subsequent seven days, by means of an electronic diary.

RESULTS

Results revealed that enhanced attentional engagement with negative vs. non-negative information predicted unique variance in intrusion frequency, whereas impaired attentional disengagement from negative vs. non-negative information predicted unique variance in intrusion controllability. These intrusion-linked patterns of attentional selectivity were evident at shorter (500 ms) stimulus exposure durations only, and not at longer (1000 ms) stimulus exposure durations.

LIMITATIONS

The current study did not assess attentional selectivity prior to the negative event. Additionally, a time-based approach, rather than an event-based approach, was employed in the assessment of intrusions.

CONCLUSIONS

The current findings suggest that engagement bias and disengagement bias may underpin differing facets of intrusive re-experiencing, raising the possibility that therapeutically targeting each type of attentional bias may attenuate a distinctive aspect of intrusive re-experiencing.

Lifetime adversity interacts with peritraumatic data-driven processing to predict intrusive memories

BACKGROUND AND OBJECTIVES

Although most trauma survivors experience some intrusive recollections of the traumatic event, only few subsequently develop posttraumatic stress disorder (PTSD). A well-established proximal risk-factor predictive of post-trauma psychopathology is peritraumatic cognitive processing. Another, more distal risk-factor is pre-trauma lifetime adversity. The present experimental analogue study tested the hypothesis that pre-trauma lifetime adversity interacts with peritraumatic perceptual (i.e., data-driven) processing to predict intrusive memory development.

METHODS

Fifty-three young adult women (non-clinical sample) indicated how much data-driven and conceptual processing they had engaged in while watching aversive film-clips (i.e., analogue trauma). On the subsequent three days, they reported intrusions of those clips. Moderation analyses tested for an interaction effect between lifetime adversity and data-driven processing in predicting intrusion load (number of intrusions weighted for their overall distress).

RESULTS

Increased data-driven processing predicted intrusion load primarily in individuals reporting more than three lifetime adversities, explaining 55% of variance. No such relationship was found for conceptual processing.

LIMITATIONS

Present analogue findings have yet to be replicated in a clinical population. Moreover, the conceptual processing scale was restricted by low internal consistency.

CONCLUSION

Present findings support the idea that intrusions are the result of poorly elaborated and primarily perceptually-formed memory traces; however, this was primarily the case in vulnerable individuals reporting several lifetime adversities. Results replicate the importance of peritraumatic processing in intrusion development but additionally point to a moderating effect of lifetime adversity.

How Expectations Shape the Formation of Intrusive Memories: An Experimental Study Using the Trauma Film Paradigm

Background

Although intrusions are the hallmark symptom of posttraumatic stress disorder, there is still limited knowledge about the processes that contribute to the development of intrusions. Here, we used the well-established trauma film paradigm (TFP) to investigate how expectations about the intensity and controllability of intrusions influence their occurrence.

Methods

90 healthy participants underwent the TFP before they were randomized to one of three conditions manipulating their expectations about intrusions: positive expectations group; negative expectations group; control group. The primary outcome was the frequency and severity of intrusive memories as assessed with an intrusion diary over seven days.

Results

The TFP was well implemented, as indicated by significant post-film anxiety and a substantial number of intrusions reported for the subsequent week. The three groups did not differ in their expectations about intrusions and, relatedly, in their experience of intrusions. A mediation analysis revealed that the influence of post-film anxiety on intrusive memories was fully mediated by expectations.

Conclusions

Despite the failure of the expectation manipulation, the results of the mediation analysis support the hypothesis that post-film expectations influence the formation of intrusive memories, suggesting that intrusions may result from maladaptive dynamics between emotional and cognitive processes following trauma(like) experiences.

Alteration of early attentional processing after analogue trauma exposure: evidence from event-related potentials

The present study aimed to determine whether exposure to an analogue traumatic event affects attentional processing of emotional information. Two groups of non-clinical participants matched on anxiety level, depression symptoms and stressful life events viewed either a trauma or a neutral film. They then performed an emotional Stroop task during which both continuous electroencephalographic activity was recorded and intrusive memories were measured. Results revealed that the valence effect (measured by the difference between emotional and neutral conditions) for the P1 amplitude was significantly greater in participants who viewed the trauma film than in participants who viewed the neutral film. This interaction was specific to words semantically related to the analogue trauma event and did not extend to all negative words. Further analyses revealed a relationship between intrusions frequency, P1 amplitude and emotional Stroop interference, indicating a link between attention and intrusive memories. Our findings suggest that exposure to potentially traumatic events has an important impact on neurocognitive function, even in the absence of psychopathology, and that this impact occurs at an early, possibly automatic stage of processing.

Using Cognitive Bias Modification-Appraisal Training to Manipulate Appraisals about the Self and the World in Analog Trauma

Background

Dysfunctional appraisals are a key mechanism in posttraumatic stress disorder (PTSD). Experimental manipulations of appraisals via Cognitive Bias Modification-Appraisal (CBM-App) training targeting cognitions related to the ‘self’ has shown to affect analog trauma symptoms. The present study aimed to conceptually replicate and extend previous findings by comparing a newly developed ‘world’ to the original ‘self’ training, and investigate the moderating role of locus of control (LOC) on intrusions.

Methods

Healthy participants (N = 173) were exposed to distressing films as an analog trauma induction. Next, participants received positive or negative CBM-App, targeting either self- or world-relevant appraisals. Dysfunctional appraisals and LOC were assessed pre- and post-training. During the week after the laboratory session, participants recorded their intrusions and associated distress in a diary. One week later, trauma-relevant symptomatology was assessed.

Results

Positive compared to negative CBM-App induced training-congruent appraisals, independent of the trained cognition (self vs. world). However, there was no effect on analog trauma symptoms and LOC did not moderate the training’s effect.

Conclusions

Our results underline the validity of CBM-App as a method to experimentally manipulate appraisals. However, since we did not fully replicate previous findings further research on mechanisms associated with transfer effects is warranted.

Distinguishing between rumination and intrusive memories in PTSD using a wearable self-tracking instrument: a proof-of-concept case study

Rumination has been shown to play a part in post-traumatic stress disorder (PTSD), but its relation to the intrusions characteristic of PTSD has mainly been investigated experimentally. This proof-of-concept case study explored the occurrence, personal experiences, and possible relation between rumination and intrusions in two PTSD patients in their daily living using a mixed method approach. A novel wearable self-tracking instrument was employed which provided fine-grained temporal resolution of observation data and could eliminate recall bias. Furthermore, quantitative and qualitative data were collected on participants’ symptoms, rumination and experiences of using the self-tracking instrument. First, without distinguishing between the two phenomena, the participants tracked both for a week. After receiving psychoeducational training for distinguishing between rumination and intrusions, the differentiated phenomena were tracked for a week. Both participants reported being subjectively able to distinguish between rumination and intrusions and made observations with high adherence during the project. Data hinted at a possible temporal relation between the phenomena in line with theories posing rumination as a maladaptive coping strategy as well as an exacerbator of PTSD symptoms. However, relations to mood were inconclusive. Furthermore, by using the self-tracking instrument, participants gained a heightened awareness of the characteristics of rumination and intrusions and contextual cues for occurrence, as well as a greater sense of momentary agency. Results reveal promising prospects in using the wearable self-tracking instrument for further investigation of the relation between rumination and intrusions in the lived lives of PTSD patients, as well as potential for incorporating this method in clinical treatment.

Key learning aims

(1)

Intrusive memories as conditioned responses to trauma cues: An empirically supported concept?

Intrusions in posttraumatic stress disorder (PTSD) are clinically understood as conditioned responses (CRs) to trauma-cues; however, experimental evidence for this is limited. We subjected 84 healthy participants to a differential conditioned-intrusion paradigm, where neutral faces served as conditioned stimuli (CSs) and aversive film clips as unconditioned stimuli (USs). While one group only completed acquisition, another group additionally received extinction. Subsequently, participants provided detailed e-diary intrusion reports. Several key findings emerged: First, participants in both groups re-experienced not only USs but also CSs as content of their intrusions. Second, intrusions were elicited by cues resembling CSs, USs, and experimental context. Third, extinction reduced probability and severity of US intrusions, and accelerated their decay, and this was particularly the case in participants showing greater cognitive (US-expectancy) and physiological (SCR) differential responding to CS+ vs. CS- at end of acquisition (i.e., conditionability). Similarly, extinction reduced CS-intrusion probability and severity, but only in participants with greater cognitive conditionability. These results support conditioning's role in re-experiencing in two critical ways: (1) Conditioning during trauma provides cues that not only function as reminder cues, but also as content of intrusions; (2) After strong conditioning, weakening the original CS-US relationship via extinction reduces intrusion formation after analogue-trauma.

Reduction in the occurrence of distressing involuntary memories following propranolol or hydrocortisone in healthy women

BACKGROUND

Pharmacological treatments targeting the neuroendocrine stress response may hold special promise in secondary prevention of posttraumatic stress disorder (PTSD). However, findings from clinical trials have been inconsistent and the efficacy of specific drugs, their temporal window of efficacy, effective doses and the characteristics of likely treatment responders remain unclear.

METHOD

Using an experimental human model of distressing involuntary memory formation, we compare the effects of two drugs that have theoretical or empirical support as secondary preventive agents in PTSD. Eighty-eight healthy women (average age: 23.5 years) received oral propranolol (80 mg), hydrocortisone (30 mg), or matched placebo immediately after viewing a 'trauma film'. They then completed daily, time-stamped intrusion diaries for 1 week, at the end of which, voluntary memory was tested.

RESULTS

While neither drug affected voluntary memory for the trauma narrative, propranolol treatment was associated with 42% fewer, and hydrocortisone with 55% fewer intrusions across the week, relative to placebo. Additionally, propranolol reduced general trauma-like symptoms, and post-drug cortisol levels were negatively correlated with intrusion frequency in the hydrocortisone group.

CONCLUSIONS

Overall, this study shows substantial reductions in intrusive memories and preserved voluntary narrative-declarative memory following either propranolol or hydrocortisone in an experimental model of psychological trauma. As such, despite some inconsistencies in clinical trials, our findings support continued investigation of propranolol and hydrocortisone as secondary preventive agents for re-experiencing symptoms of PTSD. The findings also suggest that it is critical for future research to identify the conditions governing the preventive efficacy of these drugs in PTSD.

Peritraumatic Neural Processing and Intrusive Memories: The Role of Lifetime Adversity

BACKGROUND

Pathological peritraumatic encoding is proposed as a proximal risk factor for the development of posttraumatic stress disorder (PTSD), with trauma-analog studies linking increased neural processing of trauma films to intrusive trauma recollections, a core symptom of PTSD. Cumulative lifetime adversity is proposed as a more distal risk factor, with research indicating a tipping point at about five events with regard to PTSD development following re-exposure to trauma. Thus, within a diathesis × stress framework, increased peritraumatic neural processing may constitute a specific risk factor for PTSD, particularly in individuals with several lifetime adversities.

METHODS

Fifty-three healthy women watched highly aversive films depicting severe interpersonal violence versus neutral films during functional magnetic resonance imaging, and they reported involuntary recollections during subsequent days. Moderation analyses tested the interactive relationship between peritraumatic neural processing and lifetime adversity in predicting intrusion load, i.e., the total number of intrusions weighted for their average distress.

RESULTS

Increased processing of aversive versus neutral films in the amygdala, anterior insula, dorsal and rostral anterior cingulate cortices, and hippocampus predicted increased intrusion load only in participants reporting above five lifetime adversities; for participants reporting few to none, no such relationship was found. This interactive relationship explained ≤59% of variance. Conditioned stimuli preceding film viewing mirrored this pattern.

CONCLUSIONS

Peritraumatic neural processing in multiple salience network regions and cumulative lifetime adversity interactively predicted PTSD-like symptomatology, representing a diathesis × stress framework that might guide identification of at-risk individuals and potential targets for symptom prevention after traumatic incidents.

The Prospective Influence of Trait Alexithymia on Intrusive Memories: What Is the Role of Emotional Recognition Memory?

Posttraumatic stress disorder (PTSD) is often considered to be a disorder of memory as patients suffer from fragmented uncontrollable memories (intrusions) whilst experiencing difficulties in intentionally retrieving details of the traumatic event. Recent research suggests that trait-related deficits in the identification of emotional states (alexithymia) may impact emotional memory processes in a way that promotes intrusion formation in PTSD. Therefore, we investigated the influence of alexithymia on intrusive re-experiencing and emotional recognition memory in a prospective analog study. Twenty-six healthy participants took part in a laboratory experiment, which combined two independent paradigms. Participants were exposed to a traumatic film (first session) and completed an episodic memory task comprising neutral and emotional stimuli (second session). In between sessions, participants recorded intrusive memories of the film. Individuals with higher trait alexithymia (HTA) reported an increased number of intrusions on the day of film presentation. Moreover, analyses of memory performance revealed a negative correlation between alexithymia and emotional recognition memory. Further analyses suggest that reduced emotional recognition memory, as evident in individuals with HTA, may, in turn, be associated with enhanced intrusive re-experiencing. As such, the current findings provide first indications regarding the role of alexithymia in emotional learning and PTSD. Future studies should further investigate these associations as well as potential implications for the treatment of PTSD.