Almost 15 years ago, the Institute of Medicine (1) published a landmark report reviewing clinical trials of psychological and psychopharmacological treatments for posttraumatic stress disorder (PTSD). The conclusion was surprising and damning. The committee concluded that for the large majority of treatment options there was not sufficient high-quality evidence to draw firm conclusions regarding efficacy. For psychological interventions such as EMDR, cognitive restructuring and coping skills training, and for all classes of drugs, the committee judged the evidence to be of inadequate quality to determine the efficacy of the treatments. The only treatment option with sufficient evidence to be reasonably confident about its efficacy was exposure therapies.
In the years following the Institute of Medicine review, a number of systematic reviews that both estimates the effects of treatments and evaluates the quality of the evidence have reached more or less similar conclusions. Lee and colleagues (2) set out to meta-analytically compare the efficacy of psychological vs. psychopharmacological treatments for PTSD, concluding that “[b]y every measure (…) [trauma-focused psychotherapies] were superior to medications” (p. 800). Unexpectedly, Lee et al. also judged the evidence supporting trauma-focused treatments as being of higher quality than that of psychopharmacological treatments.
Cusack et al. (3) conducted a systematic review and meta-analysis of psychological treatments of PTSD. Trauma-focused treatments such as prolonged exposure, cognitive therapy including cognitive processing therapy (CPT), EMDR, and other forms of cognitive-behavioural therapies (CBT), largely achieved comparable effect size estimates (all SMD > 1.0). However, only exposure-based treatments were judged to have an evidence-base of high quality. The strength of evidence for cognitive therapy and other forms of CBT were judged to be of moderate quality, whereas the strength of evidence for EMDR were judged to be of low quality.
In 2017 the American Psychological Association published their treatment guideline for the treatment of PTSD (4). The committee made a strong recommendation to offer patients with PTSD CBT, cognitive therapy, CPT or prolonged exposure therapy. All these treatments were judged to have medium to large treatment effects and their strength of evidence were judged to be of medium to high quality. Only prolonged exposure therapy was judged to be supported by high quality evidence. The committee made a conditional recommendation for EMDR given that it was found to have a medium to large treatment effect, but that the evidence supporting it was judged to be of low quality. The committee also made a conditional recommendation for psychopharmacological treatment in the form of SSRIs and SNRIs based on the judgement that they have a small treatment effect and that the evidence is of moderate quality.
In 2018 both the Agency for Healthcare Research and Quality (AHRQ) (5) in the US and The National Institute for Health and Care Excellence (NICE) (6, 7) in the UK published updated reviews and guidelines on the treatment of PTSD. In line with previous reviews and meta-analyses, both AHRQ and NICE found that the estimated treatment effects of trauma-focused treatments were large (SMD > 1.0). AHRQ assessed the strength of evidence supporting exposure therapy and CBT as of high quality, whereas the evidence for CPT, cognitive therapy and EMDR was evaluated as of moderate quality. With very few exceptions, all the treatment recommendations made by NICE was based on evidence evaluated as being of low to very low quality. In the network meta-analysis supporting the recommendations made by NICE, Mavranezouli et al. concluded that “TF-CBT was the treatment with the largest evidence base (…)” and that “[f]urther research is needed to establish the results for EMDR more firmly, (…) as conclusions on its effectiveness are based on a more limited evidence base compared with TF-CBT (…)” (p. 553).
In one of the latest systematic review and meta-analysis published in 2020, Lewis et al. (8) confirmed in line with previous meta-analyses that trauma-focused psychological treatments for PTSD achieves relatively large treatment effect estimates. However, Lewis et al. judged that no treatments was supported by high quality evidence. Only the evidence for trauma-focused CBT was judged to be of moderate quality, whereas the evidence supporting treatments such as prolonged exposure therapy, cognitive therapy, CPT and EMDR were all judged to be of low quality.
In conclusion, trauma-focused psychological treatments are associated with large, estimated treatments effects, and substantially so compared to psychopharmacological treatments. Thus, given the current evidence – all other things being equal, e.g. patient preferences – patients with PTSD should be offered trauma-focused psychological treatment of adequate treatment quality and dose as first-line treatment. However, as most treatments is supported by evidence usually judged to be of low to moderate quality, there is still a fair – if not substantial – amount of uncertainty whether the estimated treatment effects really represents the true treatment effects. We need more high-quality randomized controlled trials to decrease the uncertainty associated with most of our existent treatment options for PTSD.
References on request
Institute of Medicine. Treatment of posttraumatic stress disorder: An assessment of the evidence. Washington, D.C.: The National Academies Press; 2008. 224 p.
Lee DJ, Schnitzlein CW, Wolf JP, Vythilingam M, Rasmusson AM, Hoge CW. Psychotherapy versus pharmacotherapy for posttraumatic stress disorder: Systemic review and meta-analyses to determine first-line treatments. Depression and Anxiety. 2016;33(9):792-806.
Cusack K, Jonas DE, Forneris CA, Wines C, Sonis J, Middleton JC, et al. Psychological treatments for adults with posttraumatic stress disorder: A systematic review and meta-analysis. Clinical Psychology Review. 2016;43:128-41.
American Psychological Association. Clinical practice Guideline for the Treatment of Posttraumatic Stress Disorder (PTSD) in Adults. 1 ed: APA; 2017. 139 p.
Forman-Hoffman V, Middleton JC, Feltner C, Gaynes BN, Weber RP, Bann C, et al. Psychological and Pharmacological Treatments for Adults With Posttraumatic Stress Disorder: A Systematic Review Update. Agency for Healthcare Research and Quality (US), Rockville (MD); 2018. p. 616.
National Institute for Health and Care Excellence. Post-traumatic stress disorder. NICE guideline [NG116]. National Institute for Health and Care Excellence; 2018.
Mavranezouli I, Megnin-Viggars O, Daly C, Dias S, Welton NJ, Stockton S, et al. Psychological treatments for post-traumatic stress disorder in adults: a network meta-analysis. Psychological Medicine. 2020;50(4):542-55.
Lewis C, Roberts NP, Andrew M, Starling E, Bisson JI. Psychological therapies for post-traumatic stress disorder in adults: systematic review and meta-analysis. European Journal of Psychotraumatology. 2020;11(1):1729633.