Preferential processing of visual trauma-film reminders predicts subsequent intrusive memories

This study used an analogue design to test the hypothesis that preferential processing of visual trauma reminders in the aftermath of a stressful or traumatic event gives rise to subsequent intrusive memories. Shortly after the presentation of a stressful film fragment, participants (n=36) were asked to detect neutral targets (rotated buildings or nature scenes) in a single target rapid serial visual presentation (RSVP) paradigm. During half of the streams, the target was preceded by a distracter. The distracters consisted of visual images extracted from an earlier presented stressful film (e.g., persons and objects that figured in the film). The degree of interference by these film reminders predicted subsequent intrusions recorded in a one-week diary. The results provide evidence that a deficient ability to obtain attentional control over perceptual “trauma” reminders during goal-directed behaviour may set people at risk for persistent intrusive memories. Implications for research investigating attentional bias and intrusive memories in context of posttraumatic stress disorder (PTSD) are discussed.     

The use of safety behaviours to manage intrusive memories in depression

Cognitive models of clinical disorders conceptualise cognitive and behavioural safety-seeking behaviours as central to symptom persistence because they prevent disconfirmation of key maintaining beliefs. Despite growing evidence of the role of negative beliefs about intrusive memories in depression, it remains unclear why such beliefs persist. Accordingly, we examined whether safety behaviours in response to unhelpful beliefs about intrusive memories might play a role in their maintenance. Eighteen high dysphoric (i.e., BDI-II12) individuals who reported an intrusive negative autobiographical memory in the past week completed a battery of measures about their memory, associated negative beliefs and safety behaviours adopted in response to their beliefs. The most commonly endorsed beliefs reflected themes of wanting to control memories (e.g., ‘I should be able to rid my mind of this memory’) and self-deprecation about experiencing them (e.g., ‘Because I can’t control this memory, I am a weak person’). The beliefs prompted a range of safety behaviours, with cognitive distraction being the most common. The findings demonstrate that safety behaviours are common in response to maladaptive beliefs about intrusive memories. Treatment developments in this area are needed, and should incorporate strategies to challenge beliefs about memories, reduce the use of safety behaviours, and promote processing of intrusive memories.     

Characteristics and organization of the worst moment of trauma memories in posttraumatic stress disorder

It has been proposed that the organization of the worst moment in traumatic memories (“hotspots”) is of particular importance for the development of PTSD. However, current knowledge regarding the organization and content of worst moments is incomplete.In the present study, trauma survivors with (n = 25) and without PTSD (n = 54) were asked to indicate the worst moment of their trauma and to give a detailed narrative of the traumatic event. The worst moment and the remaining narrative were analyzed separately with regard to organization and emotional content.Results indicated that worst moments of trauma survivors with PTSD differed from the remaining narrative and from worst moments described by trauma survivors without PTSD in that they were characterized by more unfinished thoughts, more use of the present tense and lower levels of cognitive processing. However, hypotheses regarding differentiating emotional content were not supported. Implications for our theoretical understanding of PTSD and potential therapeutic interventions are discussed.     

Count out your intrusions: Effects of verbal encoding on intrusive memories

Peri-traumatic information processing is thought to affect the development of intrusive trauma memories. This study aimed to replicate and improve the study by Holmes, Brewin, and Hennessy (2004, Exp. 3) on the role of peri-traumatic verbal processing in analogue traumatic intrusion development. Participants viewed an aversive film under one of three conditions: counting backwards in 3s (“verbal interference”), verbalising emotions and thoughts (“verbal enhancement”), or without an extra task. A dual-process account of PTSD would predict that verbal interference would increase intrusion frequency compared to no task, whereas verbal enhancement would lead to a decrease. In contrast, mainstream memory theory predicts a decrease in intrusion frequency from any concurrent task that diverts attention away from the trauma film. The main finding was that the verbal interference task led to a decrease in intrusive memories of the film compared to the other two conditions. This finding does not support a dual-process account of PTSD, but is in line with general theories of memory and attention.     

Characteristics of intrusive memories in a community sample of depressed, recovered depressed and never-depressed individuals

An accumulating body of evidence has revealed that intrusive autobiographical memories of negative events play a role in depression. Despite increasing understanding of the phenomenological experience of these memories, previous research in this area has been conducted in either nonclinical samples, or in clinical samples without an adequate control group. This study aimed to replicate and extend findings with dysphoric samples by comparing the content and characteristics of intrusive memories in clinically depressed (n = 25), recovered (n = 30) and never-depressed (n = 30) participants. Participants completed mood measures, and a battery of self-report questionnaires that indexed intrusive memory frequency, avoidance and characteristics. Intrusive memories were common and shared strikingly similar characteristics across the three groups. The key finding was that depressed participants reported higher levels of intrusion-related distress, associated emotions (especially sadness and helplessness), interference as a result of the memories and memory vividness compared to the never-depressed group. Despite similar levels of intrusion, there were group differences in avoidance such that depressed participants reported higher levels of avoidance than the never-depressed group. These results provide further support for the proposal that clinical interventions for depression could usefully incorporate components that aim to reduce intrusive autobiographical memories and target avoidance strategies.     

Involuntary autobiographical memories in dysphoric mood: A laboratory study

The frequency and characteristics of involuntary autobiographical memories were compared in 25 stable dysphoric and 28 non-dysphoric participants, using a new laboratory-based task (Schlagman & Kvavilashvili, 2008). Participants detected infrequent target stimuli (vertical lines) in a simple vigilance task and recorded any involuntary autobiographical memories that came to mind, mostly in response to irrelevant words presented on the screen. Dysphoric participants reported involuntary memories as frequently and as quickly as non-dysphoric participants and their memories were not repetitive intrusive memories of negative or traumatic events. Additional content analysis showed that dysphoric participants did not recall more memories of objectively negative events (e.g., accidents, illnesses, deaths) than non-dysphoric participants. However, significant group differences emerged in terms of a mood congruency effect whereby dysphoric participants rated their memories as more negative than non-dysphoric participants. Moreover, the proportion of negatively rated involuntary memories was related to lower mood ratings at the end of the session in the dysphoric but not in the non-dysphoric group. Finally, groups did not differ on several memory characteristics such as vividness, specificity (high in both groups) and rates of rehearsal (low in both groups). Theoretical and practical implications of these findings for research on depression and autobiographical memory are discussed.     

Emotional memory processing in post-traumatic stress disorder affected Colombian youth

Post-traumatic stress disorder (PTSD) is a neuropsychological condition caused by exposure to chronic stressors and extreme trauma. In past decades, Colombia (South America) has experienced high levels of armed conflict, which created an environment of chronic stress, resulting in an increased incidence of PTSD in children. Limited research exists on the effects of PTSD on emotional memory functioning of these Colombian youth living in chronically stressful environments. In the present study, 23 PTSD affected youth and 26 controls were asked to recall items from a memorised word list, as well as remembering details from a short emotional story. Although no significant differences were found for word list memory, deficits for emotional story content were found in the PTSD youth, particularly for facts involving negative emotional details. The latter may suggest a deficit in executive functioning for the integration of emotionally laden stimuli, perhaps induced as a by-product of their traumatic experiences.     

The coherence of memories for trauma: Evidence from posttraumatic stress disorder

Participants with posttraumatic stress disorder (PTSD) and participants with a trauma but without PTSD wrote narratives of their trauma and, for comparison, of the most-important and the happiest events that occurred within a year of their trauma. They then rated these three events on coherence. Based on participants’ self-ratings and on naïve-observer scorings of the participants’ narratives, memories of traumas were not more incoherent than the comparison memories in participants in general or in participants with PTSD. This study comprehensively assesses narrative coherence using a full two (PTSD or not) by two (traumatic event or not) design. The results are counter to most prevalent theoretical views of memory for trauma.     

A comparison of flashbacks and ordinary autobiographical memories of trauma: content and language

We investigated hypotheses derived from the dual representation theory of posttraumatic stress disorder, which proposes that flashbacks and ordinary memories of trauma are supported by different types of representation. Sixty-two participants meeting diagnostic criteria for posttraumatic stress disorder completed a detailed written trauma narrative, and afterwards identified those sections in the narrative that had been written in flashback and ordinary memory periods. As predicted, flashback periods were characterised by greater use of detail, particularly perceptual detail, by more mentions of death, more use of the present tense, and more mention of fear, helplessness, and horror. In contrast, ordinary memory sections were characterised by more mention of secondary emotions such as guilt and anger.     

Narrative exposure therapy for political imprisonment-related chronic posttraumatic stress disorder and depression

The psychological consequences of traumatic stress may last even into old age. In persons in their 60s and 70s who had been victims of political detention and torture four decades ago, we compared the outcome of narrative exposure therapy (NET) to that of psychoeducation (PED) only. From a group of 59 former political detainees, 18 who fulfilled the full PTSD criteria according to the Composite International Diagnostic Interview (CIDI) were offered and accepted participation in the treatment study. The participants were randomly assigned to either one session of PED (n=9) or five sessions of NET (n=9). Symptoms of PTSD (CIDI) and depression (Beck Depression Inventory, BDI) were assessed prior to treatment and after a 6-month follow-up. NET but not PED produced a significant reduction in post-traumatic symptoms and depression scores. Four out of 9 of those who completed NET, compared to 8/9 of those within the PED group, still had PTSD 6 months after the treatment had ended. These results indicate that NET may lead to the alleviation of post-traumatic and depression symptoms even when the conditions persist for excessive time periods.     

Incidental retrieval of emotional contexts in post-traumatic stress disorder and depression: an fMRI study

In the present study, we used fMRI to assess patients suffering from post-traumatic stress disorder (PTSD) or depression, and trauma-exposed controls, during an episodic memory retrieval task that included non-trauma-related emotional information. In the study phase of the task neutral pictures were presented in emotional or neutral contexts. Participants were scanned during the test phase, when they were presented with old and new neutral images in a yes/no recognition memory task. fMRI results for the contrast between old and new items revealed activation in a predominantly left-sided network of cortical regions including the left middle temporal, bilateral posterior cingulate, and left prefrontal cortices. Activity common to all three groups when correctly judging pictures encoded in emotional contexts was much more limited. Relative to the control and depressed groups the PTSD group exhibited greater sensitivity to correctly recognised stimuli in the left amygdala/ventral striatum and right occipital cortex, and more specific sensitivity to items encoded in emotional contexts in the right precuneus, left superior frontal gyrus, and bilateral insula. These results are consistent with a substantially intact neural system supporting episodic retrieval in patients suffering from PTSD. Moreover, there was little indication that PTSD is associated with a marked change in the way negatively valenced information, not of personal significance, is processed.     

The organisation and content of trauma memories in survivors of road traffic accidents

We investigated the trauma narratives of 131 road traffic accident survivors prospectively, at 1 week, 6 weeks, and 3 months post-trauma. At 1 and 6 weeks, narratives of survivors with acute stress disorder (ASD) or post-traumatic stress disorder (PTSD) were less coherent and included more dissociation content. By 3 months, their narratives also contained more repetition, more non-consecutive chunks, and more sensory words. Traumatic brain injury was associated with a separate characteristic, confusion, at all three time points. Three aspects of narrative organisation at 1 week--repetition, non-consecutive chunks, and coherence--predicted PTSD severity at 3 months after controlling for initial symptoms. The results suggest both a strong concurrent and predictive relationship between narrative disorganisation and ASD/PTSD but that as people recover from ASD, their narratives do not necessarily become less disorganised.     

Younger adults report more distress and less well-being: A cross-cultural study of event centrality,depression, post-traumatic stress disorder and life satisfaction

The extent to which highly emotional autobiographical memories become central to one's identity and life story influences mental health. Young adults report higher distress and lower well-being, compared with middle-aged and/or older adults; whether this replicates across cultures is still unclear. First, we provide a review of the literature that examines age-differences in depression, post-traumatic stress disorder (PTSD), and life satisfaction in adulthood across cultures. Second, we report findings from a cross-cultural study that examined event centrality of highly positive and negative autobiographical memories along with symptoms of depression and PTSD, and levels of life satisfaction in approximately 1000 young and middle-aged adults from Mexico, Greenland, China and Denmark. Both age groups provided higher centrality ratings to the positive life event; however, the relative difference between the ratings for the positive and negative event was smaller in the young adults. Young adults reported significantly more distress and less well-being across cultures.     

Intrusive memories and rumination in patients with post-traumatic stress disorder: a phenomenological comparison

The aim of the study was to investigate the phenomenological differences between intrusive memories and rumination in PTSD. The study population consisted of 31 patients with PTSD referred for cognitive behavioural therapy to specialist services. A semi-structured interview was used to examine the characteristics of the most prominent intrusive memory and rumination. Intrusive memories were predominantly sensory experiences of short duration, whereas rumination was predominantly a thought process of longer duration. Shame was associated more with rumination than with intrusive memories. Anxiety, helplessness, numbness, and threat were greater at the time of the trauma than when experiencing the intrusive memory. In contrast, feelings like anger and sadness were greater when experiencing intrusive memories than at the time of the event. The distinction between intrusive memories and rumination is of clinical importance as intrusive memories usually decrease with imaginal reliving of the trauma, whereas rumination may require different therapeutic strategies, such as rumination-focused or mindfulness-based cognitive therapy.     

Nonbelieved memories in middle-aged and older people

Previous studies have reported that young participants typically date events that they remember, but no longer believe they experienced, to the period of childhood. The present study investigated whether participants aged between 40 and 79 years dated events related to relinquished memories to the period of childhood, as do younger people, or whether they dated such events to a period later in life. The study also compared believed and nonbelieved memories with respect to memory perspective (1st vs 3rd person perspective). Results indicated that the majority of middle-aged and older people dated nonbelieved memories to the period of childhood (median age = 8 years). No correlation was found between the participants’ current age and their age at the time the nonbelieved event occurred. In addition, results showed that believed memories were more likely to be retrieved from a 1st person perspective than were nonbelieved memories.     

Intrusive memories in depression and posttraumatic stress disorder

This study compared the stressors and consequent intrusive memories reported by matched samples of patients with posttraumatic stress disorder (PTSD) and major depression. Although intrusive memories were slightly more common among PTSD patients, both quantitative and qualitative measures revealed few differences between the groups. PTSD patients were more likely to have experienced personal illness or assault, and depressed patients family deaths and illness, and interpersonal events. Factor analysis of the associated emotions and memory characteristics suggested the existence of specific links between fear and reliving, and helplessness and out-of-body experiences. Possible inhibitory relationships between fear and sadness, and between guilt and anger, were also noted.     

Expressed emotion and causal attributions in relatives of post-traumatic stress disorder patients

This study investigates the relationship between expressed emotion (EE) and causal attributions in relatives of post-traumatic stress disorder (PTSD) patients, and examines the contributions of EE and attributions to patient outcomes. Thirty-eight relatives of patients with PTSD participating in a treatment trial were assessed on EE, causal attributions for patient problems and nature of attributions. Patients' PTSD symptoms at 6 and 12 months were assessed. Criticism and hostility in relatives were associated with attributing problems to factors controllable by patients. Relatives with marked emotional over-involvement (EOI) had an attributional profile similar to low EE relatives. Deficits in normal behaviour ("negative symptoms") were perceived as more controllable, internal and stable than were more obvious signs of an illness or mental health problem such as hypervigilance and intrusive thoughts and nightmares ("positive symptoms"). Irritability or anger was perceived as more controllable and personal than any other problem. Hostility was associated with less psychological understanding. EE (hostility) but not attributions was found to predict clinical outcome. The results are consistent with previous studies of relatives of schizophrenia patients. The study suggests a need for interventions, which focus on helping relatives to reappraise the impact of PTSD.     

Trauma-related and neutral false memories in war-induced Posttraumatic Stress Disorder

Recent models of cognition in Posttraumatic Stress Disorder (PTSD) predict that trauma-related, but not neutral, processing should be differentially affected in these patients, compared to trauma-exposed controls. This study compared a group of 50 patients with PTSD related to the war in Bosnia and a group of 50 controls without PTSD but exposed to trauma from the war, using the DRM method to induce false memories for war-related and neutral critical lures. While the groups were equally susceptible to neutral critical lures, the PTSD group mistakenly recalled more war-related lures. Both false and correct recall were related more to depression than to self-rated trauma. Implications for accounts of false memories in terms of source-monitoring are discussed.     

Overgeneral memory and suppression of trauma memories in post-traumatic stress disorder

The study investigated the relationship between the suppression of trauma memories and overgeneral memory in 42 assault survivors with and without PTSD. Overgeneral memory (OGM) was assessed with a standard autobiographical memory test (AMT). Participants completed two further AMTs under the instructions to either suppress or not suppress assault memories, in counterbalanced order. Participants with PTSD retrieved fewer and more general memories when following the suppression instruction than participants without PTSD, but not under the control instruction. OGM correlated with PTSD symptom severity, and measures of cognitive avoidance. The results are discussed with reference to current theories of overgeneral memory and its possible relationship with PTSD.     

Intrusive memories and depression in cancer patients

Matched samples of depressed and nondepressed cancer patients were interviewed about past life events, particularly experiences of death and illness. They identified and described any spontaneous intrusive visual memories they had experienced in the past week corresponding to these events. About one quarter reported such memories and, as predicted, the majority of intrusive memories concerned illness, injury and death. The mean levels of intrusion and avoidance were equivalent to patients with post-traumatic stress disorder. Consistent with prediction, depressed patients reported significantly more intrusive memories than controls, and described the memories as typically beginning with or being exacerbated by the onset of depression. Greater numbers of intrusive memories were associated with more maladaptive coping, and greater avoidance with deficits in autobiographical memory functioning.