Since 1980 more than 30.000 Danish soldiers have been serving abroad. It is estimated that 5-8 % of them develop post-traumatic stress disorder (PTSD). Medicine and psychological treatment do not always lead to an improvement in the veteran’s condition and there is a need for complementary treatments. The objective of this Ph.D. project was to explore the impact of nature-based therapy (NBT) from the perspective of veterans suffering from PTSD. The thesis consists of two studies: A systematic literature review and a qualitative single-case study.

The review aims to describe state-of-the-art research within the area of NBT, the evidence for treatment offered to veterans with PTSD, nature-assisted therapy (therapy that uses nature with the purpose of recovery), and the nature setting in which the therapy was conducted. The results pointed towards a positive benefit of nature-assisted therapy in relation to the veterans’ mental and physical wellbeing. It was concluded that more qualitative and quantitative studies are needed to contribute with knowledge that will enable us to establish nature-assisted therapy for veterans with PTSD on the basis of the evidence.

The single-case study took place in the University of Copenhagen’s therapy garden Nacadia®, located in the Hoersholm Arboretum. The aim was to explore how eight veterans experienced the NBT, the garden and the arboretum and the NBA in relation to living with PTSD. The data was collected through four individual in-depth interview rounds, which were analyzed using the Interpretative Phenomenological Analysis Method (IPA). The overall results showed that the veterans experienced a decrease in their PTSD symptoms and their symptoms were less burdensome. It became easier for them to interact socially with family and friends. The veterans experienced that their ability to be present in the moment improved through mindfulness activities and the nature-based activities. Nature became an important part of life; it provided a framework for restoration and had a recreational impact.