A Meta-Analysis of Research Examining the Relationship between Mindfulness and Posttraumatic Stress Symptoms

Abstract

Abstract Objective: Mindfulness interventions are extensively utilized for the treatment of posttraumatic stress disorder (PTSD). The question to be examined in this study is: does the current literature on mindfulness support its use as an intervention? A systematic review and meta-analysis was conducted that aggregated data from peer-reviewed journals examining the relationship between mindfulness and posttraumatic stress disorder (PTSD) symptoms in adults. Method: Multiple databases were searched to identify the population of published studies. Meta-analysis was conducted using a random effects model with the Comprehensive Meta Analysis software, version 3.3.070. Both correlational and experimental studies were included in the analysis. Results: In total, 61 studies including 6,933 participants were included for analysis. All but one study demonstrated an effect in the same direction. Thirty-eight studies were experimental in design, while 23 studies were correlational in design. Effects of mindfulness on PTSD symptoms were in the moderate range, with an overall Hedge’s g = -.576. Heterogeneity analysis revealed a high degree of variability in effect sizes in the study. Two sub analyses were also conducted. The first found a significant difference between the effect sizes of correlational and intervention studies, with Hedge’s g of -0.703 and -0.565, respectively. The second sub-analysis focused on the question of whether MBSR (Mindfulness Based Stress Reduction) interventions were significantly different from non-MBSR interventions. The difference was found to be non-significant. Several other factors were identified during the review of literature as possible covariates to explain the heterogeneity of variance. These included trauma incurred, country of study, and gender. However, meta-regression revealed that the proportion of variance explained by these covariates was not statistically significant. Conclusion: Correlational studies consistently found that as mindfulness increases, PTSD symptomatology decreases. Intervention studies consistently demonstrated that mindfulness training resulted in lowered posttraumatic stress symptoms. Limitations: Limitations of this study include the over representation of military and combat trauma in the included studies. The source and funding of these studies was from the Veteran Affairs Administration, introducing a possible bias. This study is also limited in that few moderator variables were explored, yielding minimal information about heterogeneity of variance. Implications: This appears to be the first meta-analysis on this topic. The use of mindfulness as an intervention strategy for the treatment of post-trauma symptoms is supported by this study. As more studies accumulate, future analyses can be designed to better understand the heterogeneity of study outcomes.