Braining, structured physical activity in specialized psychiatry for patients with substance use disorders-a feasibility study.

Cancer remains the leading cause of death worldwide, while at the same time more adults than ever are surviving cancer []. The number of cancer patients in South Korea has increased rapidly over the past two decades. According to the 2021 National Cancer Registration Statistics, if South Korean citizens live to their life expectancy of 83.6 years, the probability of developing cancer is 38.1% []. While cancer appears to pose one of the most serious threats to human life, continuous advancements in healthcare technology have steadily increased the 5-year survival rate of patients in South Korea. The 5-year relative survival rate for cancer patients diagnosed in the last five years (2017-2021) is estimated to be 72.1% []. Cancer survivors experience a spectrum of difficulties between the diagnosis and treatment period, as well as post recovery. Mullan (1985) classified the stages of cancer and its treatment process into three distinct phases based on the changes in the state of the disease and treatment process: the acute survival phase, where the patient is actively undergoing treatment following a cancer diagnosis; the extended survival phase, where the patient receives follow-up care after the acute treatment; and the permanent survival phase, which occurs after the patient is considered cured. It is essential that they are provided with suitable care at each step because their needs vary during each period [-]. Notably, in particular, during the extended survival phase, individuals may experience physical and mental challenges such as stress, depression, and reduced physical stamina, in addition to the fear of recurrence []. Nature is beneficial for cancer survivors while they experience cancer diagnosis and treatment. Nature-based interventions have shown promising effects on overall health and well-being in the general population []. Forest therapy, one of the nature-based interventions, is proposed as a health promotion activity for the psychological, physical, and spiritual resilience of the subjects through various environment []. According to the Act on Forest Culture and Recreation, forest healing is defined as an activity that enhances the immune system and promotes health by utilizing various elements of nature, such as fragrances and landscapes []. Forest therapy is the principle of planning and developing programs using various forest environmental elements such as plants, water and nature sounds, and maximizing healing effects according to the intervention of forest therapy instructors []. Some related studies have noted improvements in the stress [-] and mood [,] of patients undergoing forest therapy. Forest therapy is also considered to relieve tension through the control of balance in the autonomic nervous system [] and boost immune functions by relieving stress [,]. In spite of these positive effects only a few have investigated its effects on cancer survivors, for example, on quality of sleep in gastrointestinal cancer patients [] and on depression and resilience in community-dwelling cancer patients []. This implies the need for investigating the potential contribution of forest therapy in maintaining the health of cancer survivors. Measuring cortisol, serotonin, and natural killer (NK) cells in cancer survivors is important for objectively assessing stress levels and mood states, as well as understanding immune function to monitor overall health. This enables the provision of tailored support during the treatment and recovery process. Additionally, it helps scientifically verify the effectiveness of nature-based interventions like forest therapy. Accordingly, this study aims to ascertain the effects of a forest therapy program on psychological indicators such as stress and mood states and physiological indicators such as cortisol, serotonin, and NK cells of patients who have completed adjuvant therapy with cancer.