Exploring the best evidenced treatment for women veterans with PTSD who have experienced military sexual trauma.

Combat Stress recently conducted a review of the published research exploring which psychological treatments have the strongest evidence base for treating Post-Traumatic Stress Disorder (PTSD) resulting from military sexual trauma in women Veterans. The full research paper can be accessed here [1]

Military sexual trauma (or MST) is a continuum of experiences including sexual harassment, bullying and assault that takes place during military Service, and is carried out by serving military personnel against their colleagues [2]. Studies from various militaries across the globe have consistently shown that women in the Armed Forces are at a higher risk of experiencing MST compared to men.

Importantly, MST is not a diagnosis or a disorder – rather, it describes a continuum of experiences which may then result in psychological and other health problems. Research from Combat Stress showed that women who experienced sexual harassment during military Service were over two times more likely to have PTSD symptoms as a Veteran who had not, with odds increasing further for those who experienced military sexual assault [3].

That these traumatic experiences take place during military Service also matters. MST may result in a different pattern of poor health outcomes compared to similar traumatic experiences that take place at other points in a person’s life [4,5]. Although both men and women can experience MST, there is some evidence to suggest gender differences in both the potential mental health outcomes and responses to treatment [6,7].

Although guidelines exist for treatments for Veterans with PTSD (typically from combat traumas), there is no specific information on PTSD resulting from MST.

Therefore, to make sure women Veterans receive appropriate care, there is a need to understand what treatments for PTSD specifically resulting from MST in women Veterans have the strongest evidence base.

A systematic review was carried out of the peer-reviewed studies published in the 30 years up to 2022, which specifically looked at the effectiveness of different psychological therapies for PTSD resulting from MST in women Veterans. Initially, 998 different studies were identified as potentially eligible for review. This was reduced to a final collection of 12 studies from which data were taken and analysed.

A range of information was collected, including the type of treatment studied, the design of the research study (for example, a randomised controlled trial or an early-stage feasibility study), the number of Veterans included, the types of tools used to measure PTSD symptoms, and changes in the participants’ symptoms after treatment.

From this collated data, the review aimed to:

• Understand what treatments for PTSD in this group have been studied;
• Explore what treatments have the strongest evidence base for effectiveness in this group;
• Understand the wider state of research into treatments for PTSD resulting from MST in women Veterans.

The treatment evidence

In total, seven different treatments were reviewed (Table 1). These clustered into two different approaches: trauma-focused therapy and non-trauma-focused therapy. Trauma-focused therapies typically involve a focus on memories of a main traumatic event and/or related thoughts and feelings. This might involve techniques such as reimaging the traumatic experience or recounting the experience, sometimes repeatedly. Non-trauma-focused therapies, by contrast, do not directly target thoughts, memories, and feelings related to the traumatic event but instead may aim to improve wider or related coping mechanisms and skills.

Out of the reviewed treatments, Cognitive Processing Therapy (CPT) had the strongest and largest evidence base for its effectiveness in treating PTSD resulting from MST.  This is based on the number of studies, their methodologies, quality, and sample sizes, and the reduction in PTSD symptoms immediately following treatment and that lasted in the months after the end of treatment. Trauma-focused therapies in general had the strongest evidence base for treating PTSD resulting from MST in women Veterans.  One non-trauma focused therapy, Trauma Sensitive Yoga (TCTSY), had a growing evidence base for its effectiveness, but does not yet have the quality or depth of evidence base that exists for CPT.

The implications and recommendations for clinical treatment

In general, trauma-focused therapies are the recommended, gold-standard treatment for treating PTSD in Veterans in several countries, including the US and the UK.  CPT was originally designed for treating PTSD specifically resulting from sexual assault in civilian samples, and has been modified and updated since its creation. Although the evidence is unclear whether or not PTSD resulting from MST is substantively different from PTSD resulting from other types of trauma, the suitability and effectiveness of CPT as a treatment is upheld by this review.  When one considers the potentially widespread prevalence and mental health impact of MST in UK women Veterans, the use of CPT in treatment for subsequent PTSD is recommended.

All the studies reviewed reported PTSD symptom scores reduced after each of the seven treatments when comparing the average scores for their specific samples.  However, this did not mean every Veteran who took part in the studies saw a reduction in their symptoms, nor that this reduction was always classed as ‘clinically significant’, nor that every Veteran could be said to no longer have PTSD after treatment. Furthermore, a higher proportion of Veterans appear to drop out of trauma-focused therapies compared to non-trauma-focused therapies.

High dropout rates may be addressed by the way trauma-focused therapies are conducted.  In our reviewed CPT studies, the highest dropout rate was 65.2% for treatment delivered over 12 weeks, in a group setting, with Veterans attending as outpatients [8].  By contrast, CPT delivered as part of a residential programme alongside other supportive interventions reported a drop out rate of just 8.7% [9].  There may be several possible explanations for this. Nonetheless, it is worth considering that Veterans who have experienced MST often report other traumas throughout their lives, therefore more multi-faceted and integrated treatment programmes may be beneficial. Of course, entering residential treatment may not always be practical, particularly for women Veterans who may have comparatively more familial and caring responsibilities. However, clinicians should pay particular attention to other traumas and not see MST as a trauma in isolation and consider whether these experiences may also be of relevance to the treatment needed.

More widely, women Veterans may find Veteran-specific support and treatment services off-putting in that they are dominated by men; mirroring the military environments in which MST has taken place [10]. Therefore, service providers need to consider whether the wider context of how and where therapies are delivered may contribute to dropout from gold-standard, evidence-based therapies, as well as a potential lack of initial engagement by women Veterans with support providers.

The evidence about the research practices

Aside from the treatments themselves, the review also showed a large variability in how the research itself was conducted.

All of the included studies came from the United States where MST has been defined since 1999.  Despite this, across all the studies different definitions of MST were used to decide which Veterans could take part. Two studies defined MST solely as sexual assault during military Service. Two more studies also classed witnessing sexual assault as experiencing MST. Seven studies used a definition more in line with the description of a continuum used at the start of this article, whilst one study did not clearly define MST at all.

All of the included studies used a self-report measure of PTSD symptoms; either the PCL or PCL-5 depending on what year the study was conducted. However, only six studies used a more robust clinician-assessment tool to record PTSD symptoms. Surprisingly, a third of the studies did not require participants to have a diagnosis of PTSD to take part.

Although the review assessed the studies as being of average to high quality, they also used vastly different designs. Three were randomised controlled trials, but only two of these compared two different treatments. Some studies used existing data, whilst others were feasibility studies of new treatments.

The evidence about the research practices

A lack of agreement on methodologies and definitions in research means drawing good-quality comparisons between studies is extremely difficult. In many countries, including the UK, there is no statutory definition of MST – although of late, Herriott and colleagues [2] have attempted to draw one up in order to help standardise understanding and research methods.

More broadly, even though they included women who had experienced MST, several studies were excluded from the review because they did not report treatment results specifically for women Veterans who had experienced MST. More generally, the review found that very few women were included in mixed-gender Veteran samples in the first place. This under-representation or lack of detail can lead to a lack of understanding of specific Veteran groups.

Of course, the potential health outcomes from MST extend more widely than PTSD. Therefore, future research should be mindful that these too may require treatment and supportive interventions and may perhaps need to be delivered at the same time. Indeed, MST is a continuum of experiences and may not result directly in any negative health outcomes but may still affect how a Veteran engages with or accesses support services in the future.  This too is worthy of research attention.

The review featured 12 different studies, and the research on MST – in both men and women Veterans – continues to grow. The review included several novel treatments, and there is a question worth considering about the focus of future research effort.  Considering the review’s findings about dropout rates, how treatments are delivered, or the wider point that treatments may need to be appropriate for specific traumatic experiences, should the focus be on improving existing treatments or are these challenges better met by developing novel treatments?  Regardless, improving access to appropriate, effective, evidence-based treatments that offer appropriate treatment and support to Veterans should remain at the core.

Thank you Gavin Campbell and Professor Dominic Murphy for writing this Research Spotlight.

References

1. Campbell GM, Biscoe N, Williamson V, Murphy D. Evidence-based treatments for PTSD symptoms resulting from military sexual trauma in women Veterans: A systematic review. Journal of Military, Veteran and Family Health. 2024 Nov 1;10(5):30–50. Available at: [link]
2. Herriott C, Campbell G, Godier-McBard L, Wood A, Murphy D. Defining military sexual trauma: establishing parameters and perspectives. European Journal of Psychotraumatology. 2024 Dec 31;15(1):2390759. Available at: [link]
3. Hendrikx LJ, Williamson V, Murphy D. Adversity during military service: the impact of military sexual trauma, emotional bullying and physical assault on the mental health and well-being of women Veterans. BMJ Mil Health. 2021 Oct 25;169:419–24. Available at: [link]
4. Newins A, Glenn J, Wilson L, Wilson S, Kimbrel N, Beckham J, et al. Psychological Outcomes Following Sexual Assault: Differences by Sexual Assault Setting. PSYCHOLOGICAL SERVICES. 2021 Nov;18(4):504–11. Available at: [link]
5. Holder N, Maguen S, Holliday R, Vogt D, Bernhard PA, Hoffmire CA, et al. Psychosocial Outcomes Among Veteran and Non-Veteran Survivors of Sexual Assault. J Interpers Violence. 2023 Jan;38(1–2):1569–91. Available at: [link]
6. Maguen S, Cohen B, Ren L, Bosch J, Kimerling R, Seal K. Gender Differences in Military Sexual Trauma and Mental Health Diagnoses among Iraq and Afghanistan Veterans with Posttraumatic Stress Disorder. Women’s Health Issues. 2012 Jan 1;22(1):e61–6. Available at: [link]
7. Tiet QQ, Leyva YE, Blau K, Turchik JA, Rosen CS. Military sexual assault, gender, and PTSD treatment outcomes of U.S. Veterans. J Trauma Stress. 2015 Apr;28(2):92–101. Available at: [link]
8. Kelly U, Haywood T, Segell E, Higgins M. Trauma-sensitive yoga for post-traumatic stress disorder in women Veterans who experienced military sexual trauma: interim results from a randomized controlled trial. Journal of Alternative and Complementary Medicine. 2021;27(Supplement 1):S45–59. Available at: [link]
9. Voelkel E, Pukay-Martin ND, Walter KH, Chard KM. Effectiveness of cognitive processing therapy for male and female U.S. Veterans with and without military sexual trauma. Journal of Traumatic Stress. 2015;28(3):174–82. Available at: [link]
10. Campbell GM, Williamson V, Murphy D. “A Hidden Community”: The Experiences of Help-Seeking and Receiving Mental Health Treatment in U.K. Women Veterans. A Qualitative Study. Armed Forces & Society. 2025;51(1):22–45. Available at: [link]

The work was funded by a grant from the Office of Veterans’ Affairs, as part of the ENHANCE project. 

More information on this work can be found here.