Up to 90% of people will be exposed to a traumatic event over the course of their lifetime (Kilpatrick et al., 2013). Such situations involve unexpected, isolated experiences of limited duration such as rape, or can be of a more complex, longstanding nature like ongoing armed conflicts and childhood sexual abuse. Traumatic events can lead to post-traumatic stress disorder (PTSD) and symptoms associated with anxiety and depression such as negatively altered thinking about oneself and the world (Price, 2007), as well as debilitating feelings of fear, shame, guilt, and worthlessness (Lee et al., 2001).

Previous meta-analyses have found that psychological interventions such as trauma-focused cognitive behavioural therapy (TF-CBT) and eye movement desensitisation and reprocessing (EMDR) are effective for treating PTSD symptoms (Bisson & Andrew, 2007), but most studies focused on single-event PTSD.

Therefore, Coventry et al. (2020) performed a systematic review and component network meta-analysis to examine the effectiveness and acceptability of psychological and pharmacological interventions for people exposed to complex traumatic events.

Methods

The authors searched for randomised controlled trials (RCT) and non-RCTs in eight databases, including MEDLINE and the Cochrane Central Register of Controlled Trials. The chosen studies were published up to 25^th of October 2019 and followed a non-diagnostic approach, being conducted on people who had experienced complex traumatic events but did not necessarily have a formal diagnosis of PTSD. Such events included childhood physical and/or sexual abuse, domestic violence, forced migration, torture, ongoing armed conflict and combat, and human trafficking. Risk of bias was assessed using the Cochrane Risk of Bias tool (Higgins et al., 2011) for RCTs and a variant of the NICE quality appraisal checklist (NICE, 2020) for non-RCTs.

The systematic review included 116 studies, after 11,729 full articles were eliminated based on documented reasons. There was high heterogeneity in the settings of these studies, as they were conducted in hospitals (n = 50), community settings (n = 24), military clinics for veterans or active military personnel (n = 7), refugee camps (n = 5), specialist trauma clinics (n = 4), web-based or telephone-based (n = 4), in home settings (n = 2) and primary care settings (n = 2). The meta-analysis included 94 RCTs with an average length of follow-up for the primary outcome of 11.5 weeks. The 9 non-randomised studies were analysed separately. The component network meta-analysis included only 18 studies.

The interventions considered were TF-CBT (including one or more of exposure, cognitive therapy and stress management), EMDR, psychological interventions using predominantly non-CBT techniques (e.g. supportive or mindfulness-focused therapy) and pharmacological interventions (antidepressants, antipsychotics, hypnotics and anxiolytics, alpha-blocker and antihypertensive, anticonvulsants).

The primary outcome of these studies was reduction in PTSD symptoms and the secondary outcomes were anxious and depressive symptomatology, quality of life, sleep quality and positive and negative affect.

Results

The pairwise meta-analysis showed that psychological interventions were more effective than active and inactive controls in reducing PTSD symptoms at post-treatment, and at 6-month follow-up compared to inactive control. Psychological interventions also reduced anxious and depressive symptomatology and improved sleep quality at post-treatment compared to inactive control, but they did not improve quality of life significantly. However, psychological interventions were not more effective than active controls for most outcomes except for PTSD symptoms.

Phase-based psychological interventions that combined trauma-focused and skills-based strategies were the most successful with regard to interpersonal problems and emotional dysregulation. Moreover, trauma-focused approaches were more effective than non-trauma focused approaches in ameliorating PTSD symptoms across all populations, but their effectiveness was unfortunately lower in veterans and war-affected populations. Finally, according to the network meta-analysis, multicomponent interventions focusing on cognitive restructuring and imaginal exposure are the most effective for reducing PTSD symptoms.

Antipsychotic medicine and prazosin were less effective in reducing PTSD symptoms than psychological interventions and had a higher dropout rate. Pharmacological interventions were also less effective in improving sleep quality and reducing depressive symptoms and had higher dropout rates even in studies with low rates of attrition bias.

Conclusions

• Psychological interventions are more effective than pharmacological interventions in improving sleep quality and reducing PTSD and depressive symptoms and have a lower dropout rate.
• Phase-based trauma-focused interventions can help with interpersonal problems and emotional dysregulation
• Trauma-focused interventions are more effective than non-trauma focused approaches across all trauma groups, but their effectiveness is lower in veterans and war-affected populations
• Therefore, existing psychological interventions should be the first line of treatment for PTSD symptoms and related mental health problems in people who have experienced complex trauma.

Strengths and limitations

Strengths

The authors presented their analytical approach with great rigour, providing all the necessary details for an in-depth assessment of the quality of their method and analyses. The research question was made clear from the beginning of the paper and the authors reviewed a great number of controlled studies, all relevant to their aim. The quality of the included studies was assessed according to modified NICE guidelines (NICE, 2020). A key strength of this systematic review and meta-analysis was the broad, transdiagnostic approach that allowed the authors to include various populations exposed to complex trauma, not only the ones diagnosed based on the new complex post-traumatic stress disorder (CPTSD) label.

Limitations

Despite the strengths of this paper, there are numerous limitations that should be carefully considered when interpreting the current results

• Moreover, there were not enough studies focusing on comorbid psychiatric states such as BPD or on populations from prison settings and survivors of torture and modern slavery.
• There is also a lack of understanding regarding the potential harmful effects of both psychological and pharmacological interventions for complex trauma survivors.
• In addition, the network meta-analysis may have overlooked some complex trauma populations and the relative contribution of skills-based intervention for reducing PTSD symptoms.
• Finally, the reviewed studies focused on short-term outcomes, therefore not much is known about the effectiveness of psychological and pharmacological interventions in the medium- to longer-term.

Implications for practice

Psychological interventions should be confidently used to treat PTSD symptoms and mental health comorbidities and to improve sleep quality in complex trauma survivors. Trauma-focused phase-based approaches and multicomponent interventions that include cognitive restructuring and imaging exposure seem to be particularly effective in this regard. Psychological interventions are more effective and acceptable than pharmacological interventions in complex trauma, therefore they should be the first line of treatment based on current knowledge.

Future studies should focus on providing support to veterans and war-affected populations because, according to the findings of the current study, psychological interventions are not as effective for these groups. Most importantly, the complexity of the current systematic review and meta-analyses provides the ground for personalised approaches in treating complex trauma. Based on the current results, different populations could be assigned to the intervention most appropriate for their background and emotional profile using machine learning algorithms.

Statement of interests

No conflicts of interest.

Links

Primary paper

Coventry, P. A., Meader, N., Melton, H., Temple, M., Dale, H., Wright, K., … & Brown, J. V. (2020). Psychological and pharmacological interventions for posttraumatic stress disorder and comorbid mental health problems following complex traumatic events: Systematic review and component network meta-analysis. PLoS Medicine, 17(8), e1003262.

Other references

Bisson, J., & Andrew, M. (2007). Psychological treatment of post-traumatic stress disorder (PTSD). Cochrane Database of Systematic Reviews, 3, CD003388.

Kilpatrick, D. G., Resnick, H. S., Milanak, M. E., Miller, M. W., Keyes, K. M., & Friedman, M. J. (2013). National estimates of exposure to traumatic events and PTSD prevalence using DSM‐IV and DSM‐5 criteria. Journal of Traumatic Stress, 26(5), 537-547.

Higgins, J. P., Altman, D. G., Gøtzsche, P. C., Jüni, P., Moher, D., Oxman, A. D., … & Sterne, J. A. (2011). The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials. BMJ, 343, d5928.

Lee, D. A., Scragg, P., & Turner, S. (2001). The role of shame and guilt in traumatic events: A clinical model of shame‐based and guilt‐based PTSD. British Journal of Medical Psychology, 74(4), 451-466.

NICE, 2020. Methods for the Development of NICE Public Health Guidance (3rd ed.). Appendix F: quality appraisal checklist–quantitative intervention studies.

Price, J. P. (2007). Cognitive schemas, defence mechanisms and post‐traumatic stress symptomatology. Psychology and Psychotherapy: Theory, Research and Practice, 80(3), 343-353.

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