Literature Review/Introduction

Nature-based therapy as a treatment for veterans with PTSD: what do we know?

Dorthe Varning Poulsen

Abstract

Purpose – The purpose of this paper is to provide a comprehensive argument for nature-based therapy (NBT) for veterans with post-traumatic stress syndrome. It is the aim to generate an overview of the evidence for NBT to the target group. A review of available scientific literature within the field, has been comprehensively conducted. This work is the foundation for the recommendations to decision makers and politicians. Design/methodology/approach – This paper provides a conceptual analyses and a general review of the literature. Following steps have been conducted. Based on the research question, relevant work (scientific papers) have been identified using search terms in English within the three areas the target group (veterans), the diagnosis (post-traumatic stress disorder, PTSD) and treatment (NBT). Study-quality and evidence level have been assessed and discussed. Findings – The findings show a wide variation according to the interventions the nature setting, the length and frequency of the NBT session as well as the health outcome measures. The studies demonstrated a positive impact on the PTSD symptoms, quality of life and hope. None of the studies found negative impact of the interventions. Being in a group of other veterans facing the same problems was highlighted as well. Some studies measured the ability to return to workforce for the veterans and found NBT beneficial in that process. Research limitations/implications – The limitation of the research due to the methods of identifying studies. The purpose of this was to give an overview of existing literature, and there can be studies, that are not found in this process. Including qualitative and quantitative methods are useful in a process of understanding the impact of NBT for veterans with PTSD. The quantitative studies, which unfortunately are few, can give information of the extent to which the treatment affects the symptoms of PTSD. Seen in the perspective of the burden for the veterans suffering from PTSD and the economic burden for society, the process of synthesizing the research in the field in order to generate a fundament seems necessary. Practical implications – This policy papers are useful in order to make recommendations for politicians and decision makers as well as practitioners. Social implications – The burden of suffering from PTSD is heavy for the veterans and their family. The society must drive forward the development of new and better evidence-based treatment programs for veterans with PTSD. NBT might be a step in the right direction of this. Originality/value – It is well-known that there are an increase in the number of veterans diagnosed with PTSD. Generally the drop-out rate of the veterans is high in conventional treatment and it is found that veterans experience some side effects from medical treatment. NBT is, in existing research, found to have a positive impact on the veterans, and therefore, it should be part of future treatment programs for veterans with PTSD.

Keywords PTSD, Recommendations, Veterans, Nature-based therapy, Post-traumatic stress syndrome

Paper type General review

Introduction

This paper describes society’s obligation to provide appropriate treatment to military personnel who are suffering from post-traumatic stress disorder (PTSD) following war service. Furthermore, the paper reviews nature-based therapy (NBT) as a relevant component of an overall treatment.

PTSD can occur after experiencing or witnessing traumatic events (American Psychiatric Association, 2013). Combat-related PTSD is a condition that has huge personal implications for the individual and his family, and poses an economic burden for society. The prevalence of PTSD among the US troops returning from Afghanistan and Iraq has been reported at 14-15 per cent (Gates et al., 2012), and for UK troops the number is 3-5 per cent (Fear et al., 2010; Richardson

Received 29 August 2016 Revised 17 October 2016 Accepted 17 October 2016

Dorthe Varning Poulsen is an Assistant Professor at the Department of Geosciences and Natural Resource Management, University of Copenhagen, Frederiksberg, Denmark.

DOI 10.1108/JPMH-08-2016-0039 VOL. 16 NO. 1 2017, pp. 15-20, © Emerald Publishing Limited, ISSN 1746-5729 j JOURNAL OF PUBLIC MENTAL HEALTH j PAGE 15

et al., 2010). Furthermore, the number of soldiers with symptoms compatible with PTSD in the USA and the UK has increased (Atkinson et al., 2009; Tanielian and Jaycox, 2008). An important part of this story is that veterans are diagnosed several years after having experienced the traumatic events and not, as previously, within six months after the onset of symptoms. A Danish cohort study of veterans from the war in Afghanistan found an increase in the percentage of soldiers with PTSD symptoms; the figure increased from 3 per cent at the time of homecoming to 9.4 per cent three years after the time of homecoming (Andersen et al., 2013).

The treatment offered to war veterans often consists of either psychological treatment or pharmacotherapy, or a mix of these two treatment forms. Exposure therapy and cognitive therapy are recommended in clinical treatment guidelines in several countries (Forbes et al., 2010; Castillo et al., 2014; Resick et al., 2015). In spite of these recommendations, a percentage of the veterans deselect the treatment offered; Hoge found that up to 44 per cent of veterans in the USA do not receive the recommended treatment or drop out of their treatment programme (Hoge et al., 2014). Therefore, it seems urgent to seek out alternative treatments that work, are acceptable to war veterans with PTSD, and that have a positive impact on the individual’s overall life. In this regard, NBT is a promising option.

The aim of this paper is to summarize the existing evidence of the benefits of NBT for veterans with PTSD, to identify strengths and weaknesses in the research conducted, and, based on this, to make recommendations with regard to how to incorporate NBT as a part of the treatment offered to war veterans with PTSD.

NBT

NBT covers a variety of interventions in which the nature setting (designed or natural) and the therapeutic programs constitute a relationship that is adjusted to the need of the target group (Stigsdotter et al., 2011). The treatment is based on the theory that environmental psychology and natural environments are seen as supportive for human health (Stigsdotter and Grahn, 2003; Stigsdotter et al., 2011). Moreover, it draws on Kaplan’s (1995) theory suggesting that nature can help to replenish our mental and attentional capacity. Fatigue of the brain can occur when the brain’s capacity to focus on a specific task has reached its limit. Though the interaction between the ambient environment, i.e. green activities that have a therapeutic effect, and knowledge of the special needs of the target group, NBT offers a very real and relevant form of treatment.

In NBT, the therapeutic approach varies from, e.g. mindfulness-based methods, cognitive therapy or, the development of special skills in relation to nature and horticulture. Even though the overall goal is to enhance the veterans’ self-confidence and ability to deal with everyday life situation, the therapeutic aspect is an inseparable part of NBT. Thus it is very important to differentiate between NBT and outdoor activities. Outdoor activities have a purpose in themselves and are not directly related to healing; they might have a positive impact on the participants’ mental and physical being in the moment, but they are not designed to lead to the individual’s recovery. And therefore they should not be included in the assessment of a treatment for veterans with PTSD.

Below is an overview of existing research within the area of NBT for war veterans with PTSD. Based on this overview, important matters as well as issues that need further research will be identified with a view to preparing an evidence-based guideline for NBT for veterans that will benefit both the veterans and society.

Overview of the existing research

The purpose of this literature review is to give an overview of research concerning NBT for veterans with PTSD. This review uses the term “NBT” defined by Corazon et al. (2010) as “a therapeutic intervention targeting the need of a special population, where the natural environment is specially designed or specially chosen for the particular therapeutic activity”. NBT can be seen as an umbrella-term for different types of therapy also referred to as ecotherapy, horticultal therapy and therapeutic horticulture.

PAGE 16 j JOURNAL OF PUBLIC MENTAL HEALTH j VOL. 16 NO. 1 2017

A search strategy was developed inspired from The Cochrane Centre; The Cochrane Handbook for Systematic Reviews of Interventions (Higgins and Green, 2008).

Search terms within the field of the three foci (“Therapy”, “Target group” and “Diagnose”) were developed (Table I).

Looking at the field as a whole, there is a huge contrast between the commonness of treatment programmes for veterans with PTSD involving “nature” (a Google search generated more than 800,000 hits) and the lack of scientific studies of NBT programmes.

A broad search of papers published from 1995-2016 based on English search terms within the field of “NBT”, “veterans” and “PTSD” was conducted. Two reviews including, respectively, 19 (Poulsen et al., 2015) and eight studies (Bird, 2014) was found. Additionally, six studies were identified. The quality of the studies was assessed using recommendations from Cochrane Handbook (Higgins and Green, 2008). RCT studies are recommended in reviews of medical intervention, because they test the effectiveness of various types of medical intervention (Higgins and Green, 2008; Popay et al., 1998). In spite of this, only few RCT studies have examined NBT for veterans with PTSD. A systematic review (Poulsen et al., 2015) included only two RCT studies published in the period from 1996 to 2015. The same picture was seen in a review focussing on treatment of Australian veterans in which the author concluded that research in this area is based mainly on “small self-selected sample sizes and a lack of randomised controlled groups” (Bird, 2014). The two reviews found a greater number of qualitative designed studies: (Poulsen and Stigsdotter, 2015) included 17 of such studies and Bird included eight papers in his review. Qualitative studies are often used in social research because of their value with regard to investigating complex and sensitive issues (Bryman, 2015), but as described above, they are not usually part of reviews of medical interventions. The consequences of not including this type of research in this particular field might be that rigorous data that are relevant to policy are not included in review studies. A transparent assessment of the methodology’s quality before analyzing the data, as done by Poulsen (Poulsen and Stigsdotter, 2015) is required. So what may be seen as a weakness from a medical methodological perspective can instead be viewed as a quality in research within the social research, and bring deeper insight into the participants’ experience of the treatment and life perspective. This paper argues for a biopsychosocial approach (Borrell-Carrio et al., 2004; Engel, 1989) and therefore, the qualitative as well as the quantitative studies are reviewed.

Results

In general, the interventions varied especially with regard to the setting, the length and frequency of intervention and also the health outcome measures. A measurement in the studies is the individual’s ability to return to the workforce. This is an interesting measurement, because of the high rate of unemployment among veterans (Resnick and Rosenheck, 2008; Smith et al., 2005) and the resulting economic consequences for the individual and society. Concrete skills such as horticulture and gardening give the veterans competences that are described as transferable from the context of the garden to the personal life of the veterans (Poulsen and Stigsdotter, 2015). In spite of the differences between the studies, there is a tendency that an extended treatment period of one month instead of shorter compressed intervention periods (days or a week) has an impact in the long term (Poulsen et al., 2015). Some studies describe improved physical health as a consequence of the physical demands of green activities. Physical health is an important measure because of the known negative impact of PTSD on general health. Most of the researched papers mentioned the veterans’ experience of being part of a group with

Table I The table gives an overview of the search strategy

Search topic Therapy Target group Diagnose

Search terms (only in English)

Nature-based therapy, ecotherapy, horticultural therapy

Veterans, soldiers, military personnel, servicemen

Post-traumatic stress disorder (PTSD), combat disorder, war-related trauma

Databases Medline, Pubmed, Cochrane Library, CINAHL, PILOTS, Google Scholar

VOL. 16 NO. 1 2017 j JOURNAL OF PUBLIC MENTAL HEALTH j PAGE 17

other veterans who face the same type of problems. This feeling of belonging to a group breaks down the feeling of being stigmatized and isolated (e.g. Atkinson, 2009; Detweiler et al., 2010). Two studies found a significant reduction in PTSD symptoms and depression, an improvement in functioning, in hope, and sense of control of the symptoms of PTSD (Duvall and Kaplan, 2013; Gelkopf et al., 2013; Hyer et al., 1996), whereas Hyer et al. (1996) only found this in the qualitative part of their study. A recent study (Detweiler et al., 2015) that used cortisol levels and questionnaires as a measurement of the severity of PTSD in veterans, found no significant difference in the cortisol levels for the two treatment groups (one group was treated with horticultural therapy (HT) and the other group was treated with occupational therapy (OT). However, the qualitative part of the study did show that the majority of participants benefitted more from HT than OH. Only one study followed the participants after the intervention (Poulsen et al., 2015). This qualitative study examined a ten-week NBT programme; after one year the veterans were found to have benefited from the therapy in that their PTSD symptoms were less severe and their sense of control had improved. Furthermore, the majority of the group had returned to work or education.

Conclusion and recommendations for policy makers

Society is facing an increasing number of war veterans experiencing symptoms of PTSD after serving in war zones. Added to this, a number of studies indicate there is a connection between PTSD and an increased rate of physical health issues, substance abuse, and unemployment. Treatment most often focusses on medical treatment and trauma-focussed psychological therapy. The literature discusses whether medical treatment can cure PTSD or merely offers symptom relief. Studies show that many veterans do not seek help or drop out of the programmers offered. This leaves a group of veterans and their families with the burden of dealing with the PTSD symptoms in their daily lives.

Even though the majority of the studies have a qualitative approach and only a few RCT studies have been identified, the results with regard to the effect of NBT are consistently positive and no negative impact from NBT has been reported.

The qualitative studies of NBT provided to veterans contribute with knowledge regarding the complex condition of living with PTSD. More well-structured RCT studies are needed in the area. Such studies, combined with relevant transparent qualitative studies must be the foundation for developing clear guidelines for NBT. Therefore, the following steps are recommended:

■ Development of a set of measurement tools with a multi-method approach that captures the different challenges the veterans are facing, and provides a basis for comparing the results of different projects;

■ Clear and transparent description of the therapeutic approach and interaction with nature enabling practitioners (therapists) to use this approach, to make the treatment transparent and transferable to the practice sector; and

■ Clear distinctions between outdoor activities and NBT. Outdoor activities do not involve a specific therapeutic effort, and are therefore not a treatment even though it appears so in the literature.

References

American Psychiatric Association (2013), Diagnostic and Statistical Manual of Mental Disorders, 5th ed., American Psychiatric Association, information center, veteran center, the Ministry of Defence.

Andersen, S.B., Madsen, T., Karstoft, K., Elklit, A., Nordentoft, M. and Bertelsen, M. (2013), Efter Afghanistan- Rapport Over Soldaters Psykiske Velbefindende to Et Halvt År Efter Hjemkomst.

Atkinson, J. (2009), “An evaluation of the Gardening Leave project for ex-military personnel with PTSD and other combat related mental health problems”, unpublished research report, Gardening Leave, June.

Atkinson, M.P., Guetz, A. and Wein, L.M. (2009), “A dynamic model for posttraumatic stress disorder among US troops in operation iraqi freedom”, Management Science, Vol. 55 No. 9, pp. 1454-68, available at: http://pubsonline.informs.org/action/showCitFormats?doi=10.1287%2Fmnsc.1090.1042

PAGE 18 j JOURNAL OF PUBLIC MENTAL HEALTH j VOL. 16 NO. 1 2017

Bird, K. (2014), “Peer outdoor support therapy (POST) for Australian contemporary veterans: a review of the literature”, Journal of Military and Veterans Health, Vol. 22 No. 1, p. 4.

Borrell-Carrio, F., Suchman, A.L. and Epstein, R.M. (2004), “The biopsychosocial model 25 years later: principles, practice, and scientific inquiry”, Annals of Family Medicine, Vol. 2 No. 6, pp. 576-82.

Bryman, A. (2015), Social Research Methods, Oxford University Press, New York, NY.

Corazon, S.S., Stigsdotter, U.K., Jensen, A.G.C. and Nilsson, K. (2010), “Development of the nature-based therapy concept for patients with stress-related illness at the Danish healing forest garden Nacadia”, Journal of Therapeutic Horticulture, Vol. 20, pp. 30-48.

Castillo, D.T., Lacefield, K., Baca, J., Blankenship, A. and Qualls, C. (2014), “Effectiveness of group-delivered cognitive therapy and treatment length in women veterans with PTSD”, Behavioral Sciences, Vol. 4 No. 1, pp. 31-41.

Detweiler, M.B., Sharma, T., Lane, S., Kim, M., Johnson, B.C. and Kim, K.Y. (2010), “The case for using restorative natural environments in veterans’ rehabilitation programs”, Federal Practitioner, Vol. 27, pp. 26-8.

Detweiler, M.B., Self, J.A., Lane, S., Spencer, L., Lutgens, B., Kim, D., Halling, M.H., Rudder, T.F. and Lehrmann, L. (2015), “Horticultural therapy: a pilot study on modulating cortisol levels and indices of substance craving, posttraumatic stress disorder, depression, and quality of life in veterans”, Alternative Therapies in Health and Medicine, Vol. 21 No. 4, p. 36.

Duvall, J. and Kaplan, R. (2013), “Exploring the benefits of outdoor experiences on veterans”, Sierra Club Foundation, Ann Arbor, MI.

Engel, G.L. (1989), “The need for a new medical model: a challenge for biomedicine”, Holistic Medicine, Vol. 4 No. 1, pp. 37-53.

Fear, N.T., Jones, M., Murphy, D., Hull, L., Iversen, A.C., Coker, B., Machell, L., Sundin, J., Woodhead, C., Jones, N., Greenberg, N., Landau, S., Dandeker, C., Rona, R., Hotopf, M. and Wessely, S. (2010), “What are the consequences of deployment to Iraq and Afghanistan on the mental health of the UK armed forces? A cohort study”, The Lancet, Vol. 375 No. 9728, pp. 1783-97.

Forbes, D., Creamer, M., Bisson, J.I., Cohen, J.A., Crow, B.E., Foa, E.B. Friedman, M., Keane, T.M., Kudler, T.M. and Ursano, R.J. (2010), “A guide to guidelines for the treatment of PTSD and related conditions”, Journal of Traumatic Stress, Vol. 23 No. 5, pp. 537-52.

Gates, M.A., Holowka, D.W., Vasterling, J.J., Keane, T.M., Marx, B.P. and Rosen, R.C. (2012), “Posttraumatic stress disorder in veterans and military personnel: epidemiology, screening, and case recognition”, Psychological Services, Vol. 9 No. 4, pp. 361-82.

Gelkopf, M., Hasson-Ohayon, I., Bikman, M. and Kravetz, S. (2013), “Nature adventure rehabilitation for combat-related posttraumatic chronic stress disorder: a randomized control trial”, Psychiatry Research, Vol. 209 No. 3, pp. 485-93.

Higgins, J.P. and Green, S. (2008), Cochrane Handbook for Systematic Reviews of Interventions, Wiley Online Library, available at: http://handbook.cochrane.org/ (accessed 30 September 2016).

Hoge, C.W., Grossman, S.H., Auchterlonie, J.L., Riviere, L.A., Milliken, C.S. and Wilk, J.E. (2014), “PTSD treatment for soldiers after combat deployment: low utilization of mental health care and reasons for dropout”, Psychiatric Services, Vol. 65 No. 8, pp. 997-1004.

Hyer, L., Boyd, S., Scurfield, R., Smith, D. and Burke, J. (1996), “Effects of outward bound experience as an adjunct to inpatient PTSD treatment of war veterans”, Journal of Clinical Psychology, Vol. 52 No. 3, pp. 263-78.

Kaplan, S. (1995), “The restorative benefits of nature: toward an integrative framework”, Journal of Environmental Psychology, Vol. 15 No. 3, pp. 169-82.

Popay, J., Rogers, A. and Williams, G. (1998), “Rationale and standards for the systematic review of qualitative literature in health services research”, Qualitative Health Research, Vol. 8 No. 3, pp. 341-51.

Poulsen, D.V. and Stigsdotter, U.K. (2015), “Battles fought in nature: lessons learned from nature-based treatment in a forest therapy garden for soldiers with posttraumatic stress disorder”, in Dustin, D., Bricker, K., Negley, S., Brownlee, M., Schwab, K. and Lundberg, N. (Eds), This Land is Your Land – Toward a Better Understanding of Nature’s Resiliency-Building and Restorative Power for Armed Forces Personnel, Veterans, and their Families, Sagamore Publishing LLC, Urbana, IL, pp. 103-11.

VOL. 16 NO. 1 2017 j JOURNAL OF PUBLIC MENTAL HEALTH j PAGE 19

Poulsen, D.V., Stigsdotter, U.K. and Refshage, A.D. (2015), “Whatever happened to the soldiers? Nature-assisted therapies for veterans diagnosed with post-traumatic stress disorder: a literature review”, Urban Forestry & Urban Greening, Vol. 14 No. 2, pp. 438-45.

Resick, P.A., Wachen, J.S., Mintz, J., Young-McCaughan, S., Roache, J.D., Borah, A.M., Borah, E.l.V., Dondanville, K.A., Hembree, E.A., Litz, B.T. and Peterson, A.L. (2015), “A randomized clinical trial of group cognitive processing therapy compared with group present-centered therapy for PTSD among active duty military personnel”, Journal of Consulting and Clinical Psychology, Vol. 83 No. 6, p. 1058.

Resnick, S.G. and Rosenheck, R.A. (2008), “Posttraumatic stress disorder and employment in veterans participating in veterans health administration compensated work therapy”, Journal of Rehabilitation Research and Development, Vol. 45 No. 3, p. 427.

Richardson, L.K., Frueh, B.C. and Acierno, R. (2010), “Prevalence estimates of combat-related post-traumatic stress disorder: critical review”, The Australian and New Zealand Journal of Psychiatry, Vol. 44 No. 1, pp. 4-19.

Smith, M.W., Schnurr, P.P. and Rosenheck, R.A. (2005), “Employment outcomes and PTSD symptom severity”, Mental Health Services Research, Vol. 7 No. 2, pp. 89-101.

Stigsdotter, U.A. and Grahn, P. (2003), “Experiencing a garden: a healing garden for people suffering from burnout diseases”, Journal of Therapeutic Horticulture, Vol. 14, pp. 38-49.

Stigsdotter, U.K., Palsdottir, A.M., Burls, A., Chermaz, A., Ferrini, F. and Grahn, P. (2011), “Nature-based therapeutic interventions”, in Nilsson, K., Sangster, M., Gallis, C., Hartig, T., de Vries, S., Seeland, K. and Schipperijn, J. (Eds), Anonymous Forests, Trees and Human Health, Springer, New York, NY, Dordrecht, Heidelberg and London, pp. 309-42.

Tanielian, T.L. and Jaycox, L. (2008), Invisible Wounds of War: Psychological and Cognitive Injuries, their Consequences, and Services to Assist Recovery, Rand Corporation, Santa Monica, CA.

Corresponding author

Dorthe Varning Poulsen can be contacted at: [email protected]

For instructions on how to order reprints of this article, please visit our website: www.emeraldgrouppublishing.com/licensing/reprints.htm Or contact us for further details: [email protected]

PAGE 20 j JOURNAL OF PUBLIC MENTAL HEALTH j VOL. 16 NO. 1 2017

Reproduced with permission of copyright owner. Further reproduction prohibited without permission.