Comparative efficacy and acceptability of expressive writing treatments compared with psychotherapy, other writing treatments, and waiting list control for adult trauma survivors: a systematic review and network meta-analysis

Abstract

Background: Expressive writing about a traumatic event is promising in treating posttraumatic stress disorder (PTSD) symptoms in adult trauma survivors. To date, the comparative efficacy and acceptability of this approach is uncertain. Therefore, we aimed to examine the comparative efficacy and acceptability of expressive writing treatments.

Methods: We included 44 RCTs with 7724 participants contributing 54 direct comparisons between expressive writing (EW), enhanced writing (i.e. including additional therapist contact or individualized writing assignments; EW+), PTSD psychotherapies (PT), neutral writing (NW), and waiting-list control (WL).

Results: EW, EW+, PT, and NW were statistically significantly more efficacious than WL at the longest available follow-up, with SMDs (95% CI) of -0.78 (-1.10 to -0.46) for PT, -0.81 (-1.02 to -0.61) for EW+ , -0.43 (-0.65 to -0.21) for EW, and -0.37 (-0.61 to -0.14) for NW. We found small to moderate differences between the active treatments. At baseline mean PTSD severity was significantly lower in EW+ compared with WL. We found considerable heterogeneity and inconsistency and we found elevated risk of bias in at least one of the bias dimensions in all studies. When EW+-WL comparisons were excluded from the analyses EW+ was no longer superior compared with EW.

Conclusions: The summarized evidence confirms that writing treatments may contribute to improving PTSD symptoms in medium to long-term. Methodological issues in the available evidence hamper definite conclusions regarding the comparative efficacy and acceptability of writing treatments. Adequately sized comparative randomized controlled trials preferably including all four active treatment approaches, reporting long-term data, and including researchers with balanced preferences are needed.

Keywords: (partial) PTSD; PTSD symptoms; comparative efficacy; expressive writing; network meta-analysis.

Fig. 1.

Flow chart of study inclusion.

Fig. 2.

Network of included comparisons. The size of the nodes indicates the number of studies per treatment. The thickness of the edges represents the number of comparisons between two treatment approaches.

Fig. 3.

Comparative efficacy of expressive writing as compared with active and passive comparators. Results (SMD and 95% CI) on the comparative efficacy from network meta-analyses (grey) and from standard pairwise meta-analyses (white) at the end of treatment (a), at longest available follow-up including all 44 RCTs (b), and from the exploratory analyses excluding two-arm studies which directly compared EW+ with WL (c). To make network and pairwise meta-analysis results directly comparable, estimates are presented as column v. row for the network meta-analyses, and row v. column for the pairwise meta-analyses. Statistically significant results are printed in bold. EW, expressive writing; EW+, enhanced writing; CI, confidence interval; NW, neutral writing; PT, psychotherapy; SMD, standardised mean difference; WL, waiting list.

Fig. 4.

Comparative acceptability of expressive writing as compared with active and passive comparators. Results (RR and 95% CI) based on drop-out rates between beginning and end of treatment from network meta-analyses (grey) and standard pairwise meta-analyses (white). To make network and pairwise meta-analysis results directly comparable, estimates are presented as column v. row for the network meta-analyses, and row v. column for the pairwise meta-analyses. Statistically significant results are printed in bold. EW, expressive writing; EW+, enhanced writing; CI, confidence interval; NW, neutral writing; PT, psychotherapy; RR, relative risk; WL, waiting list.