The effectiveness of narrative exposure therapy : a review, meta-analysis and meta-regression analysis

Background: Narrative exposure therapy (NET) is a short-term psychological treatment for post-traumatic stress disorder (PTSD) that has been investigated in various contexts among traumatized refugees and other trauma survivors. Sustained treatment results have been reported, but the methodological quality of the trials needs a more thorough examination. 

Objective: To evaluate the effectiveness of NET for survivors of trauma, using a quality assessment, an updated meta-analysis, and a meta-regression analysis. 

Method: Following a systematic literature selection, the methodological quality of the included studies was assessed; Non-controlled and controlled effect sizes (Hedges’ g) were estimated using a random effects model. Predictor analyses were performed. Non-controlled effect sizes for PTSD and depression included symptom change at post-treatment and follow-up time-points. Controlled effect sizes included post-treatment comparisons of NET with non-active and active comparators: both trauma-focused (TF) and non-trauma-focused (non-TF) interventions. 

Results: The selected studies showed high external validity; methodological quality was equivalent to other guideline-supported TF interventions. In 16 randomized controlled trials, involving 947 participants, large non-controlled effect sizes were found for PTSD symptoms, at post-treatment (g = 1.18, 95% confidence interval [0.87; 1.50]) and follow-up (g = 1.37 [0.96; 1.77]). For depression symptoms, medium non-controlled effect sizes were found, at post-treatment (g = 0.47 [0.23; 0.71]) and follow-up (g = 0.60 [0.26; 0.94]). Post-treatment, NET outperformed non-active comparators and non-TF active comparators for PTSD, but not the combined active comparators. For depression, NET only outperformed non-active comparators. Advancing age predicted better treatment results for PTSD and depression symptoms; a history of migration predicted smaller treatment results for depression symptoms. 

Conclusions:The findings of this meta-analysis suggest that patients and providers may expect sustained treatment results from NET. Controlled comparisons with other guidelinesupported TF interventions are not yet available.