Distant Memories: A Prospective Study of Vantage Point of Trauma Memories

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PS YC HOLOGICA L SC IENCE

Research Report

Distant Memories A Prospective Study of Vantage Point of Trauma Memories Lucy M. Kenny,1 Richard A. Bryant,1 Derrick Silove,1 Mark Creamer,2 Meaghan O’Donnell,2 and Alexander C. McFarlane3 1

University of New South Wales, 2University of Melbourne, and 3University of Adelaide

ABSTRACT—Adopting

an observer perspective to recall trauma memories may function as a form of avoidance that maintains posttraumatic stress disorder (PTSD). We conducted a prospective study to analyze the relationship between memory vantage point and PTSD symptoms. Participants (N 5 947) identified the vantage point of their trauma memory and reported PTSD symptoms within 4 weeks of the trauma; 730 participants repeated this process 12 months later. Initially recalling the trauma from an observer vantage point was related to more severe PTSD symptoms at that time and 12 months later. Shifting from a field to an observer perspective a year after trauma was associated with greater PTSD severity at 12 months. These results suggest that remembering trauma from an observer vantage point is related to both immediate and ongoing PTSD symptoms. Cognitive models of posttraumatic stress disorder (PTSD) propose that avoidance plays an important role in both the development and maintenance of the disorder (Brewin, Dalgleish, & Joseph, 1996; Foa, Steketee, & Rothbaum, 1989). These models suggest that avoidance of trauma memories limits the processing of trauma memories and associated emotional reactions, which in turn maintains PTSD. These models are supported by evidence of a link between the avoidance of trauma-related material and PTSD (Dunmore, Clark, & Ehlers, 1999; Harvey & Bryant, 1998). Despite this role of avoidance, individuals with PTSD are characterized by frequent recollections of their trauma (McMillen, North, & Smith, 2000; Reynolds & Brewin, 1998). This pattern raises the question of why this exposure to trauma memories does not result in the processing and resolution of these memories. One possible answer is that individuals with PTSD become adept at minimizing the emotional impact of the memory by

Address correspondence to Richard A. Bryant, School of Psychology, University of New South Wales, Sydney, NSW 2052, Australia, e-mail: [email protected]

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recalling it from an observer perspective; that is, as if they were a spectator watching the event (Carden˜a & Spiegel, 1993; Foa & Rothbaum, 1998; Freinkel, Koopman, & Siegel, 1994). There is convergent evidence that observer-vantage memories are associated with less distress (McIsaac & Eich, 2002, 2004; Nigro & Neisser, 1983; Robinson & Swanson, 1993), suggesting that remembering traumatic events from an observer vantage point may act as a form of emotional avoidance. This hypothesis is consistent with evidence of an association between observer memories and avoidance after trauma (Kenny & Bryant, 2007). The observer vantage point contributes to PTSD reactions because it may limit emotional processing of trauma memories. To clarify the relationship between vantage point and development of PTSD symptoms, we conducted a prospective analysis of the relationship between memory vantage point and PTSD symptoms. We interviewed survivors of traumatic injury within a month of their trauma and again at 12 months after the trauma to index the vantage point of their trauma memory and their level of PTSD symptoms at both time points. We predicted that an observer vantage point would be associated with both initial and subsequent PTSD severity. METHOD

Participants Participants were 1,166 recent trauma survivors who had been admitted to any of four major trauma hospitals in any of three Australian cities as a result of traumatic injury. Individuals were recruited to participate in the study if they met the following conditions: They experienced a physical injury that required hospital admission of at least 24 hours; they were able to comprehend interview questions without the aid of an interpreter; they were between 18 and 65 years of age; they had no greater than mild traumatic brain injury; and they received no diagnosis of organic mental disorder or psychosis. Of the 1,166 participants who agreed to participate in the study, 1,101 were asked about memory vantage point in the initial assessment. Of these, 947 (86%) were able to identify the

Copyright r 2009 Association for Psychological Science

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Vantage Point of Trauma Memories

vantage point of their trauma memories. Of these participants, 685 (72%) were male and 262 (28%) were female; the average age of these participants was 38.2 years (SD 5 13.5 years). In terms of trauma, 592 (63%) of the participants were involved in motor vehicle accidents, and the remaining participants were involved in assaults (n 5 55; 6%), falls (n 5 146; 15%), workrelated accidents (n 5 72; 8%), or suffered other injuries (n 5 82; 8%). The average hospital admission for these participants was 12.0 days (SD 5 12.0 days). Participants were interviewed an average of 7.4 days after their admission (SD 5 6.3). We followed up with 849 (77.1%) of the initial participants after 12 months. Participants with whom we followed up at 12 months did not differ significantly from those with whom we did not follow up in terms of gender, initial vantage point, or days spent in hospital (p > .05). Participants with whom we did not follow up were younger than participants who completed the follow-up, t(1, 934) 5 3.6, p < .01. Eighty-nine (10.5%) of participants were either not asked or could not nominate a vantage point of their trauma memory at the follow-up assessment, resulting in 730 participants providing a vantage point at 12 months.

Measures Clinician-Administered PTSD Scale The Clinician-Administered PTSD Scale (CAPS; Blake et al., 1995) is a structured clinical interview designed to assess the frequency and severity of all symptoms of PTSD within the last month. The CAPS was used to assess symptoms experienced since the trauma at the initial interview, and within the previous month at the 12-month interview.

Vantage-Point Measure Participants were asked the following question about their trauma memory vantage point: ‘‘When you think back to what happened to you, do you see the event through your own eyes or do you see it from an observer’s or an onlooker’s point of view?’’ If participants indicated that their vantage point included both vantage points, they were encouraged to indicate the vantage point from which they predominantly remembered the event.

Procedure Participants were approached in the hospital as soon as they were medically stable, between 1 and 42 days after their admission. After participants provided written informed consent, a trained research assistant administered the CAPS and asked them about their initial memory vantage point. Twelve months after the trauma, participants were contacted via telephone and were administered the CAPS and were asked about their trauma memory vantage point.

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RESULTS

Initial Memory Vantage Point In terms of vantage point, 814 participants (86%) reported recalling the event predominantly from a field perspective (i.e., first-person perspective), and 133 participants (14%) reported recalling the event predominantly from an observer perspective. Fifty-seven participants reported both vantage points, and were excluded from subsequent analyses. Participants who reported a field perspective did not differ from those who reported an observer perspective in terms of gender, age, length of hospitalization, or trauma-assessment interval. Participants who had experienced an assault (12%) were more likely to recall their trauma from an observer perspective than participants who had experienced other types of trauma (5%), w2(1, N 5 890) 5 6.7, p < .01. Of participants with whom we followed up at 12 months, 584 (80%) reported recalling their trauma predominantly from a field perspective, and 146 (20%) reported recalling their trauma predominantly from an observer perspective. Seventy-three participants reported both vantage points, and were excluded from subsequent analyses. Vantage point at 12 months was not related to gender, age, or length of stay in hospital. Subsequent analyses excluded participants who reported both vantage points at either assessment; that is, 548 participants were retained in analyses. Sixty-six participants (9%) had a different vantage point at 12 months than the one they reported in the initial phase. Of those participants who initially reported a field perspective, 44 (9%) reported an observer perspective at 12 months. Of those participants who initially reported an observer perspective, 23 (66%) reported a field observer perspective at 12 months. Participants whose memory vantage point changed between the initial interview and the 12-month follow-up did not differ from those who maintained a consistent vantage point in terms of age, gender, number of days in hospital, or type of trauma. Those who initially reported an observer vantage point were significantly more likely to have their vantage point change than those who initially reported a field vantage point, w2(1, N 5 548) 5 23.6, p < .001.

Memory Vantage Point and PTSD Severity Table 1 presents CAPS total scores for participants with field and observer memories. A 2 (initial vantage point) ! 2 (12month vantage point) ! 2 (initial CAPS score, 12-month CAPS score) analysis of variance (ANOVA) indicated a three-way interaction effect, F(1, 544) 5 4.78, p 5 .03, Zp2 5 .009. To clarify this effect, separate 2 (12-month vantage point) ! 2 (initial CAPS score, 12-month CAPS score) ANOVAs were conducted for participants who reported initial field perspectives and those who reported initial observer perspectives. Among participants who reported an initial field perspective, there was a main effect for CAPS scores, F(1, 511) 5 11.15, p 5 .001, Zp2 5 .02, and a

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L.M. Kenny et al.

TABLE 1 Participants’ Scores on the Clinician-Administered Posttraumatic Stress Disorder Scale (CAPS) as a Function of the Vantage Points Taken When Responding to the Scale CAPS score Combination of vantage pointsa Field-field Field-observer Observer-field Observer-observer

Initial

12 months

15.5 (15.4) 15.7 (16.3) 17.8 (17.7) 28.2 (28.4)

16.6 (20.9) 23.7 (20.8) 22.3 (29.7) 24.6 (22.6)

Note. Standard deviations are given in parentheses. a Participants reported their vantage point each time they responded to the CAPS. In each combination listed, the vantage point for the initial administration of the CAPS is listed first, and the vantage point for the second (12month) administration is listed second.

significant 12-Month Vantage Point ! CAPS Scores interaction effect, F(1, 511) 5 6.43, p 5 .01, Zp2 5 .01. That is, participants who reported an initial field perspective reported higher CAPS scores at 12 months than at baseline. Participants who initially reported a field perspective but subsequently reported an observer perspective at 12 months reported higher CAPS than those who persisted with a field perspective (p < .05). There were no main or interaction effects among participants who initially held an observer perspective. Additionally, participants who reported a field perspective at baseline reported lower baseline CAPS scores than those who reported an observer perspective, F(1, 544) 5 5.26, p 5 .02, Zp2 5 .01. Participants who reported a field perspective at 12 months had lower 12month CAPS scores than those who reported an observer perspective, F(1, 544) 5 6.58, p 5 .01, Zp2 5 .01. Participants were classified as having PTSD (n 5 49; 9%) or not having PTSD (n 5 503; 91%) at 12 months. Because observer perspective appears to be associated with more severe PTSD at baseline and follow-up, we explored the predictive capacity of adopting an observer perspective at baseline in predicting subsequent PTSD. Accordingly, a logistic regression was conducted to determine the predictive capacity of vantage point in relation to other likely predictors of PTSD: days in hospital, gender, and trauma type. After adjusting for days in hospital, gender, and trauma type, participants who initially reported an observer vantage point had a higher probability of having PTSD at 12 months (adjusted odds ratio 5 2.67; 95% confidence interval 5 1.11–6.46). Days in hospital and trauma type were not predictive of PTSD (p > .05); however, gender was a significant predictor (adjusted odds ratio 5 2.21; 95% confidence interval 5 1.21–4.05). DISCUSSION

These results indicate that adopting an observer perspective when remembering a trauma in the initial weeks after its occurrence is not only related to more severe PTSD symptoms at

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that time, but is also associated with a two-fold increase in the probability of having PTSD 12 months later. These results are consistent with findings that an observer vantage point for a memory limits the aversive emotional responses associated with trauma memories (McIsaac & Eich, 2004) and with evidence that adopting an observer perspective is associated with avoidance tendencies after trauma (Kenny & Bryant, 2007). Our study advances the understanding of the role of observer memory because of its prospective design. Shifting from a field perspective after the trauma to an observer perspective 1 year later was associated with greater PTSD levels at 12 months. One interpretation of this pattern is that participants shifted toward an observer perspective because the trauma memories were more distressing over time, and that adopting an observer perspective functioned as an attempt to reduce the adverse emotions associated with the memory. Previous research indicated that vantage point can change over time, and that people tend to recall events from an observer viewpoint at later time points (Frank & Gilovich, 1989; Nigro & Neisser, 1983; Robinson & Swanson, 1993). Nonetheless, the finding that changes were associated with levels of PTSD at 12 months suggests that the observed changes in vantage point are linked to severity of trauma memories rather than simply the passage of time. Overall, our results demonstrated a relationship between memory vantage point and PTSD symptoms; this finding supports the proposal that recalling a trauma from an observer vantage point is associated with poorer post-trauma recovery. When combined with the results of previous studies showing that observer memories are associated with lower levels of emotional intensity (McIsaac & Eich, 2004) and with higher levels of cognitive and behavioral avoidance (Kenny & Bryant, 2007), these results suggest that recalling a traumatic experience from an observer perspective may serve to maintain avoidance of trauma memories, and also may prevent adequate processing of the traumatic experience. Consequently, adopting an observer perspective may impede adequate emotional processing of the memories, and this pattern may contribute to maintenance of PTSD symptoms (Brewin et al., 1996; Foa et al., 1989). Some procedural limitations must be mentioned. First, by limiting participants to identifying the most prominent vantage point of their memories, important information about aspects of a particular participant’s memories that were characterized by observer or field perspectives may have been lost. Second, participants were not asked about the level of distress associated with trauma memories. Although the results of previous studies suggest that observer memories are associated with lower levels of distress than field memories (McIsaac & Eich, 2002, 2004), we did not directly assess distress levels. Third, the design of the study did not allow inferences about the direction of the relationship between observer memories and PTSD symptoms. That is, it is not clear from the results of this study whether adoption of the observer vantage point occurred as a response to distress, or

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whether the adoption of an observer vantage point was causal in the development of these symptoms. Future studies should aim to investigate the direction of this relationship by manipulating memory vantage point in the aftermath of trauma and determining the relative influences of initiating an observer or field perspective on trauma memories. It is also possible that participants may have encoded the trauma from a specific vantage point, which could influence recall perspective. This possibility is indicated by evidence that trauma survivors can experience the event from an observer perspective (Harvey & Bryant, 1999). Finally, we note that our design did not allow inferences about the intentionality of memory perspectives; future studies could investigate how vantage point is involuntarily or intentionally adopted. In conclusion, the results of this study support the proposal that the way in which people remember traumatic experiences is related to their subsequent PTSD levels. This finding is worth further exploration because, if adopting an observer perspective is predictive of subsequent PTSD, encouraging field perspectives after trauma may have beneficial effects by facilitating emotional processing of trauma memories. It is worth noting that one of the most potent treatments for PTSD is exposure therapy, which typically requires the individual to recall the trauma from a field perspective to heighten the distress and thereby maximize learning of the idea that one can master the trauma memory (Bryant et al., 2008). The potential for facilitating mastery of traumatic stress by facilitating a field vantage point requires study by prospectively studying adaptation after trauma in individuals whose vantage point of trauma memories has been manipulated to adopt either field or observer perspectives. REFERENCES Blake, D.D., Weathers, F.W., Nagy, L.M., Kaloupek, D.G., Klauminzer, D., Charney, D., & Keane, T. (1995). The development of a Clinician-Administered PTSD Scale. Journal of Traumatic Stress, 8, 75–90. Brewin, C.R., Dalgleish, T., & Joseph, S. (1996). A dual representation theory of posttraumatic stress disorder. Psychological Review, 103, 670–686. Bryant, R.A., Mastrodomenico, J., Felmingham, K., Hopwood, S., Kenny, L., Kandris, E., et al. (2008). Treatment of acute stress

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disorder: A randomized controlled trial. Archives of General Psychiatry, 65, 659–667. Carden˜a, E., & Spiegel, D. (1993). Dissociative reactions to the San Francisco Bay Area earthquake of 1989. American Journal of Psychiatry, 150, 474–478. Dunmore, E., Clark, D.M., & Ehlers, A. (1999). Cognitive factors involved in the onset and maintenance of posttraumatic stress disorder (PTSD) after physical or sexual assault. Behaviour Research and Therapy, 37, 809–829. Foa, E.B., & Rothbaum, B.O. (1998). Treating the trauma of rape: Cognitive behavioral therapy for PTSD. New York: Guilford Press. Foa, E.B., Steketee, G., & Rothbaum, B.O. (1989). Behavioral/cognitive conceptualizations of post-traumatic stress disorder. Behavior Therapy, 20, 155–176. Frank, M.G., & Gilovich, T. (1989). Effect of memory perspective on retrospective causal attributions. Journal of Personality and Social Psychology, 57, 399–403. Freinkel, A., Koopman, C., & Spiegel, D. (1994). Dissociative symptoms in media eyewitnesses of an execution. American Journal of Psychiatry, 151, 1335–1339. Harvey, A.G., & Bryant, R.A. (1998). The relationship between acute stress disorder and posttraumatic stress disorder: A prospective evaluation of motor vehicle accident survivors. Journal of Consulting and Clinical Psychology, 66, 507–512. Harvey, A.G., & Bryant, R.A. (1999). Dissociative symptoms in acute stress disorder. Journal of Traumatic Stress, 12, 673–680. Kenny, L.M., & Bryant, R.A. (2007). Keeping memories at an arm’s length: Vantage point of trauma memories. Behaviour Research and Therapy, 45, 1915–1920. McIsaac, H.K., & Eich, E. (2002). Vantage point in episodic memory. Psychonomic Bulletin & Review, 9, 409–420. McIsaac, H.K., & Eich, E. (2004). Vantage point in traumatic memory. Psychological Science, 15, 248–253. McMillen, J.C., North, C.S., & Smith, E.M. (2000). What parts of PTSD are normal: Intrusion, avoidance, or arousal? Data from the Northridge, California, earthquake. Journal of Traumatic Stress, 13, 57–75. Nigro, G., & Neisser, U. (1983). Point of view in personal memories. Cognitive Psychology, 15, 467–482. Reynolds, M., & Brewin, C.R. (1998). Intrusive cognitions, coping strategies and emotional responses in depression, post-traumatic stress disorder and a non-clinical population. Behaviour Research and Therapy, 36, 135–147. Robinson, J.A., & Swanson, J.A. (1993). Field and observer modes of remembering. Memory, 1, 169–184. (RECEIVED 4/28/08; REVISION ACCEPTED 2/9/09)

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