Efficacy and mechanisms of change in trauma-focussed writing interventions for post-traumatic stress

Abstract

Trauma-focussed writing therapies (TF-WTs) encompass a range of brief writing interventions for subthreshold and clinical PTSD that have been found to produce significant change in symptoms of posttraumatic stress (PTS). These therapies have the potential to reduce symptoms of PTS at a low-cost to the individual and society, and within a shorter timeframe than other evidence-based therapies. However, there is a need for further research in TF-WTs, particularly with regards to replications of earlier findings, clarifying differences in writing protocols, and explorations of mechanisms accounting for their outcomes. It was therefore the aim of the current thesis to investigate the efficacy and mechanisms of TF-WTs.

The present thesis used a mixed-methods approach to meet these aims. First, a systematic review and meta-analysis on the efficacy of TF-WTs in reducing PTS symptoms and producing clinical response was conducted. The results demonstrated that TF-WTs are efficacious when compared to waitlist and placebo writing control conditions. The evidence was mixed regarding the efficacy of TF-WTS in comparison to other psychotherapies. However, overall, the results were limited by a modest number of studies conducted, limited range of comparators, and high or unclear risk of bias across the majority of studies.

The results from this review informed the study that followed, which was a randomised control trial of two TF-WTs (one emphasising repeated exposure to the traumatic memory and the other emphasising cognitive reprocessing of the traumatic memory) in comparison to a positive experiences writing (PEW) control. Eighty-three (n = 83) adults with elevated PTS were randomised into one of these three conditions. Each condition involved three weekly telehealth appointments with a researcher-psychologist and 20-minutes of writing during the appointment. Writing instructions changed depending on allocated condition. The study had three primary aims: (1) the assessment of the efficacy of two TF-WTs in comparison to PEW in reducing PTS and producing clinically meaningful change, (2) an investigation into the mechanisms of change that produce outcomes in these two TF-WTs in comparison to PEW (putative mechanisms included the role of negative cognitions, expectancy violation, self-compassion and social support), and (3) a qualitative analysis of participants' written feedback from participating in the study. Findings indicated that the two TF-WTs were not efficacious in comparison to PEW. Instead, significant reductions in PTS and clinical change was observed in all conditions. Furthermore, there was no support for the role of the proposed mechanisms in producing outcomes, with the exception of a preliminary result on the role of self-compassion mediating outcomes in the cognitive reprocessing TF-WT only. Finally, qualitative analyses identified a range of important themes indicating the benefits of TF-WTs according to participants, as well as the drawbacks and suggestions for improving the protocols.

The results of the present thesis suggest emerging evidence for the role of TF-WTs in reducing symptoms of PTS and producing clinically meaningful change. However, similar outcomes are demonstrated in comparison to writing about positive experiences, suggesting that neither writing about trauma nor writing about positive events is uniquely beneficial to outcomes. In addition, the results indicate that the mechanisms of TF-WTs remain poorly understood. Taken together, more research is needed to clarify how TF-WTs are producing change in symptoms of PTS, and whether there are unique mechanisms compared to other forms of writing. The thesis ends with a discussion on limitations, and the theoretical, clinical and research implications of these results. Show more