PTSD treatment guidelines invariably point to trauma-focused therapy, such as trauma-focused cognitive behavioral therapy (TF-CBT) or Eye Movement Desensitization and Reprocessing (EMDR) as preferred interventions. Is the trauma focus justified? Researcher and psychologist Joris Haagen tells the story of a heated academic debate…

An article by Benish, Imel and Wampold (2008) challenged our belief in the necessity of a trauma focus. According to the authors it does not matter which psychological intervention we employ and whether it is trauma-focused or not. Could this mean that traumatized patients needlessly suffer from therapeutic exposure to horrific memories? The article was the start of a fiery debate between prominent researchers.

Let’s start with the initial article itself. Dr. Benish et al. published a meta-analysis with data from 15 studies and 958 patients in PTSD treatment. The aims of their meta-analysis were most unusual; whereas the last decades were dedicated to the discovery of the most effective therapies, based on the assumption that the effectiveness varies between interventions, Benish et al. assumed and tested the reverse: all therapeutically-intended interventions are equally efficacious.

They collected data from high quality intervention studies that included only ‘bona fide’ PTSD psychotherapy. A psychotherapy was considered bona fide if it was intended to be therapeutic, which was assessed using the following criteria:

1. delivered by a trained therapist and included an interaction between the patient and therapist to build a relationship;
2. tailored to the individual patient; and
3. based on an established psychological approach.

Interventions that did not specifically target PTSD were excluded. Such interventions are often used to ‘control’ for non-specific (therapist or patient) treatment effects that might account for treatment outcome. Non-specific variables are present in all interventions and are not considered unique to a certain intervention. An example is the therapist’s empathy for a patient. Researchers often employ ‘control’ interventions instead of waiting lists because a) it is more ethical to offer some form of therapy rather than no therapy at all and b) to examine the added value of a promising experimental intervention beyond the effects of the control intervention.

The interventions in Benish’s analysis included EMDR, TF-CBT, present centered therapy, psychodynamic therapy, stress inoculation therapy, and exposure therapy. Benish et al. did not find any significant differences between the various PTSD interventions, no matter whether they consisted of interventions recommended by (international) guidelines or other, non-trauma-focused interventions. The differences between effect sizes were, on average, small, and not dependent on a certain type of intervention. In other words, not a single intervention was more effective than any other intervention.

Benish et al. concluded that non-trauma-focused interventions, such as psychodynamic therapy, would be equally effective as trauma-focused interventions, such as EMDR. As such, the authors are critical of any preferential treatment interventions for PTSD. They stated that there are no treatment-specific ingredients of essential importance in the therapeutic recovery from PTSD and patients would benefit more from the widest range of intervention options tailored to the needs and wishes of each client.

According to the authors, these findings are supported by the outcomes of treatment ‘dismantle’ studies that test the effectiveness of specific treatment components instead of the complete intervention. Dismantle studies would suggest that the components are interchangeable as they do not differ in effectiveness. Benish et al. further claimed that ‘common factors’ influence treatment regardless of the type of interventions used and emphasize the need to prevent treatment dropout because its influence would outweigh the benefits of a single type of intervention. In short: the preferential status of first-choice PTSD interventions should cease to exist.

A protest ensues as several prominent researchers (Bisson, Creamer, Schnurr) reviewed the work of Benish et al. with prof. Anke Ehlers as principal investigator (Ehlers et al., 2010). Their response is clear: Benish et al. are wrong. Ehlers et al.’s main argument states that the inclusion of ‘bona fide’ interventions according to the classification criteria used by Benish et al. distorts the results.

Ehlers et al. claim that the classification criteria erroneously excluded certain interventions, such as supportive interventions, that are often used to treat PTSD patients instead of merely serving as a control intervention to account for any non-specific variables. The classification criteria used by Benish et al. was subjective and opaque and caused the exclusion of precisely those studies that demonstrate differences in the effectiveness between trauma-focused and other interventions.

At times, Ehlers et al. are quite forthright and perhaps a bit harsh in their criticism; one might perceive the slightest hint of accusatory tones in their writings that the applied classification criteria plays well into the hands of the Benish et al. omnibus hypothesis (all interventions are equally effective).

However, Bruce Wampold defends the findings of his student Benish and offers a riposte…

Part 2 of this saga will be posted next month, stay tuned!

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References:

Benish, S., Imel, Z., & Wampold, B. (2008). The relative efficacy of bona fide psychotherapies for treating post-traumatic stress disorder: A meta-analysis of direct comparisons Clinical Psychology Review, 28, 746-758 DOI: 10.1016/j.cpr.2007.10.005

Ehlers, A., Bisson, J., Clark, D., Creamer, M., Pilling, S., Richards, D., Schnurr, P., Turner, S., & Yule, W. (2010). Do all psychological treatments really work the same in posttraumatic stress disorder? Clinical Psychology Review, 30, 269-276 DOI: 10.1016/j.cpr.2009.12.001

(These blogposts are an adaptation of Joris’ previous publication in the Dutch journal Cogiscope)