Author: Alexandra Canty
Canty, Alexandra, 2024 Using Experience Sampling Methodology (ESM) to improve our understanding of day-to-day intrusion experiences and persistent post-trauma impacts in survivors of trauma, Flinders University, College of Education, Psychology and Social Work
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Cognitive theories of posttraumatic stress disorder (PTSD) that underpin the foundations of current psychological interventions have largely been investigated by comparing groups over extended time periods, leaving gaps in our understanding of the time scales and inter-individual processes that allow trauma reactions to persist. Researchers in the trauma field are increasingly employing intensive repeated measure designs, such as Experience Sampling Methodology (ESM), to explore these processes and test key tenets of their underlying theoretical base. This thesis adopts an intensive ESM, informed by Ehlers and Clark’s (2000) cognitive model of PTSD, to examine intrusion related factors proposed to be integral to the development and maintenance of the disorder.
Study 1a captured 100 trauma exposed individuals’ intrusions, related distress, negative appraisals of intrusions, and maladaptive coping over a 10-day ESM protocol. Using multi-level modelling this study found significant intra-personal contemporaneous relationships that supported Ehlers and Clark’s (2000) model, representing the first, comprehensive demonstration of these relationships in an intensive time frame. Other key findings were that intrusion related distress was more strongly related to appraisals and maladaptive coping than intrusion frequency and unexpected cross-level interactions indicated that individuals with fewer maladaptive coping tendencies than others were more reactive to day-to-day changes in distress and coping.
Study 1b then used Random Intercept Cross Lagged Panel Modelling (RI-CLPM) to examine select Study 1a data in greater detail, focusing on the relationships surrounding intrusion related distress. Maladaptive coping was split to model avoidance coping and rumination separately, revealing different associations for each strategy that suggest they influence trauma reactions in diverse manners. These models also demonstrated that not all the contemporaneous relationships observed in Study 1a translated to consistent covariance in individual time-points, with negative appraisals of intrusions appearing more stable across a single day than related distress and coping. Comparing models of Day 1, 5, and 10 data showed that the patterns of relationships between all factors of interest changed throughout the ESM assessment period.
Finally, Study 2 randomly assigned 64 trauma exposed individuals to either a brief online intervention aimed to improve intrusion appraisals and adaptive coping strategy engagement, or control period, prior to engaging in a 7-day ESM protocol. Overall, from baseline measures to post-ESM, participants reported significant improvements in symptoms of PTSD. The only significant group difference was that individuals who received the intervention reported significantly greater reductions in negative appraisals than individuals in the control group. Moreover negative-cross level interactions for avoidance coping replicated some interactions observed in Study 1a.
Ultimately these findings provided valuable insight to inter-individual relationships occurring day-to-day in trauma reactions, providing further robust testing of dominant cognitive models of PTSD (such as Ehlers & Clark, 2000) and a more nuanced understanding of individual factors (i.e., ‘avoidance’) often treated as a homogenous construct in previous research. Although this thesis demonstrated the utility of ESM in furthering our understanding of trauma reactions, continued examination of these mechanisms and the broader applications of ESM are needed, with substantial potential for future research as well as clinical applications.
Keywords: PTSD, Posttraumatic Stress, Intrusions, Experience sampling methodology, Diary
Subject: Psychology thesis
Thesis type: Doctor of Philosophy
Completed: 2024
School: College of Education, Psychology and Social Work
Supervisor: Professor Reg Nixon