The effect of cognitive behavior therapy-based psychotherapy applied in a forest environment on physiological changes and remission of major depressive disorder

Heart rate vARiability and physical activity in inpatient treatMent of burnOut and DepressIon (HARMODI): protocol of a cross-sectional study with up to 8-week follow up

INTRODUCTION

Chronic stress can cause an imbalance within the autonomic nervous system, thereby affecting cardiovascular and mental health. Physical activity (PA) may have a positive effect on the autonomic nervous system and stress-related disorders, such as depression and burnout. Heart rate variability (HRV) is a non-invasive marker of the autonomic nervous system. However, limited and inconsistent data exist on the exact relationship between HRV, PA and depression and burnout symptoms. The HARMODI study aims to explore whether HRV is a feasible marker of depression and burnout symptoms and aims to evaluate the role of PA in the treatment of stress-related disorders.

METHODS AND ANALYSES

This is an observational study with a cross-sectional up to 8 week follow-up study design. A total of 153 patients, undergoing psychiatric inpatient treatment with burnout syndrome (Z73) and depressive episode (F32 or F33) or adjustment disorder (F43.2), will be recruited. Data on depression and burnout symptoms, HRV recordings (24-hour, supine, standing and exercise stress test), cognitive function, cardiorespiratory fitness, cardiovascular health, balance and strength will be collected at baseline (T1) and after up to 8 weeks (T2). Continuous data on PA and Ecological Momentary Assessments of exhaustion, mood and tension will be monitored daily throughout inpatient treatment. Multiple regression models, adjusted for potential confounders, will assess the association between HRV as the primary outcome, PA and depression and burnout severity score.

ETHICS AND DISSEMINATION

The protocol has been approved by Swiss Ethics Committee, Cantonal Ethics Committee Zürich. Results of HARMODI will be disseminated through peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05874856.

Cortisol interdependence during psychotherapy in major depressive disorder

The current study explored cortisol interdependence between patients and therapists during psychotherapy, the possible moderating effect of patient alliance ratings on this interdependence, and the associations between cortisol interdependence and treatment outcome. While cortisol interdependence was explored in other interpersonal contexts, its presence in psychotherapy has remained unexplored. We hypothesized that (a) patients' and therapists' cortisol levels at pre-session will predict their own and their partner's subsequent cortisol levels at post-session, (b) patient ratings of their relationship with their therapists will moderate these partner effects, and (c) cortisol interdependence will be associated with better treatment outcome. Fifty dyads undergoing 16 weeks of psychodynamic treatment for major depressive disorder participated in this study. Patient-therapist salivary cortisol samples were collected at eight time points, alongside a post-session patient-rated alliance questionnaire and a symptom severity interview. For analyses we employed the actor-partner interdependence model. Results revealed that (a) patients' and therapists' cortisol levels before sessions predicted their own post-session cortisol changes. However, significant cortisol interdependence was observed in patients' pre-session cortisol levels predicting therapists' post-session cortisol levels. Furthermore, (b) poorer alliance ratings associated with more pronounced cortisol interdependence, and (c) in dyads where patient pre-session cortisol predicted therapist's post-session cortisol, a better treatment outcome was found. This study found novel evidence of cortisol interdependence in psychotherapy and is partially in line with other studies inspecting cortisol interdependence in adjacent research fields. These findings emphasize the intricate psychophysiological interactions within therapeutic relationships and their associations with treatment outcome.

Shinrin-Yoku (Forest Bathing): A Scoping Review of the Global Research on the Effects of Spending Time in Nature

Background

This Scoping review (ScR) builds upon the 2017 review conducted by Hansen et al which contributed to evidence base shinrin-yoku (SY), also known as forest bathing (FB), has many positive health effects and is becoming a prescribed dose (specific time spent in nature) by health care providers. Practice and research regarding SY, has been historically based in Asian countries with a recent increase in Europe. The need and call for more research worldwide continues to further the evidence of SY as a health promotion modality. Through this ScR the authors identified programmatic components, health information monitored and screened, time spent in nature, geographical regions, trends, and themes in SY research worldwide.

Methods

Following PRISMA-ScR guidelines we searched across 7 electronic databases for SY or FB research articles from 2017 through 2022. PubMed, CINAHL, PsycInfo, ScienceDirect, SCOPUS, Embase, JSTOR were included due to the interdisciplinary nature of SY or FB research. Each database provided unique strengths ensuring a capture of a wide range of articles. The resulting articles were screened and extracted through Covidence.

Results

Database searches returned 241 results, with 110 references removed during the deduplication process, 131 were initially screened in the title and abstract review stage. Resulting in 82 unique results deemed relevant and screened in full text. During the final stage of the review, 63 articles met all inclusion criteria and were extracted for data.

Conclusions

The practice of SY has physiological (PHYS) and psychological (PSYCH) benefits across age groups. Research findings indicate either the natural or the virtual environment (VW) has significant health benefits. Continued research is encouraged globally for short- and long-term health outcomes for all individuals. The connection with nature benefits the mind, body and soul and is supported by Henry David Thoreau's philosophy: "Our livesneed the relief of where the pine flourishes and the jay still scream."

Cortisol as a Target for Treating Mental Disorders: A Promising Avenue for Therapy

Cortisol, commonly known as the "stress hormone," plays a critical role in the body's response to stress. Elevated cortisol levels have been associated with various mental disorders, including anxiety, depression, and post-traumatic stress disorder. Consequently, researchers have explored cortisol modulation as a promising avenue for treating these conditions. However, the availability of research on cortisol as a therapeutic option for mental disorders is limited, and existing studies employ diverse methodologies and outcome measures. This review article aimed to provide insights into different treatment approaches, both pharmacological and non-pharmacological, which can effectively modulate cortisol levels. Pharmacological interventions involve the use of substances, such as somatostatin analogs, dopamine agonists, corticotropin-releasing hormone antagonists, and cortisol synthesis inhibitors. Additionally, non-pharmacological techniques, including cognitivebehavioral therapy, herbs and supplements, transcranial magnetic stimulation, lifestyle changes, and surgery, have been investigated to reduce cortisol levels. The emerging evidence suggests that cortisol modulation could be a promising treatment option for mental disorders. However, more research is needed to fully understand the effectiveness and safety of these therapies.

Effects of an Integrative Day Care Clinic Program with a Focus on Nature Therapy in a Hospital Park Setting on Quality of Life in Oncological Patients-A Non-Randomized Controlled Study

Cancer often causes long-term physical and psychological impairments. Lifestyle modification and nature-based interventions (NBIs) can have a positive impact on patients' quality of life (QOL). This participants-blinded, non-randomized controlled study assessed parameters at weeks 0, 12, and 24, including, as a primary endpoint, QOL in cancer patients on the Functional Assessment of Cancer Therapy-General (FACT-G) at week 12. QOL in breast cancer patients, fatigue, well-being, stress, anxiety/depression, socio-psychological well-being, benefits of nature interaction, insomnia, self-efficacy, mindfulness, and self-compassion were assessed as secondary endpoints. N = 107 cancer patients (96.3% women; 52.5 ± 9.3 years, 80.4% breast cancer) were assigned to either a 12-week nature-based (NDC; n = 56) or conventional (DC; n = 51) oncology day care clinic program, whereby the assignment group was not known to the participants. There was no significant group difference for the primary endpoint. At week 24, QOL, fatigue, mindfulness and self-compassion scores were significantly higher, and at weeks 12 and 24, the insomnia score was significantly lower in NDC compared to DC. In conclusion, this study indicates positive and clinically relevant effects of the program on QOL, fatigue, and psychological parameters. NBIs seem to have a more pronounced effect.

Do Mental Health Changes in Nature Co-occur with Changes in Heartrate Variability and Executive Functioning? A Systematic Review

PURPOSE OF REVIEW

Given the global burden of mental health issues, new solutions are needed to promote mental health. Nature exposure represents a promising option to promote mental health, but the mechanisms are poorly understood. Recent frameworks have argued that changes in mental health in nature are caused by activity changes in the vagus nerve, which connects the heart and the brain, and that these changes also improve executive functioning (EF) abilities. This suggests that changes in mental health symptomology in nature should be accompanied by changes in vagus nerve activity, as well as changes in executive functioning. Yet, little work has systematically examined co-variation of these outcomes in empirical studies. The present manuscript systematically examines whether changes in mental health in nature are accompanied by changes in vagus nerve activity (approximated by heartrate variability) and changes in executive functioning.

RECENT FINDINGS

There is compelling evidence that spending time in nature can increase heartrate variability, improve mental health, and improve executive functioning. However, despite strong theoretical claims that these three outcomes should be linked after spending time in nature settings, few studies directly examine such co-occurrence. The study systematically examines whether studies that considered both mental health and executive functioning (n = 6) showed co-occurring effects in response to nature exposure. Similarly, the study also considers if studies examining mental health and heartrate variability (n = 6) showed similarly directional effects following nature exposure. This systematic review concludes with discussion about the limited number of studies (n =1) that include all three measures. We find mixed results of co-occurrence with these variables, suggesting that the relationship between these three constructs in nature may be more nuanced than current theory suggests. Perhaps more importantly, our results demonstrate that there is very little existing work linking changes in mental health to changes in EF and vagal tone. We conclude with justification for why it may be beneficial for researchers to include all three metrics as well as guidance on how to do so.

The effect of an internet-based intervention for depression on cortisol and alpha-amylase

INTRODUCTION

Psychotherapeutic interventions for major depressive disorder (MDD) have been suggested to be associated with a normalization of biological stress system (i.e., the hypothalamic-pituitary-adrenal axis and the autonomic nervous system) dysregulation. Furthermore, pre-intervention cortisol parameters have been identified as prescriptive biological markers of treatment success. However, evidence of treatment effects on the biological stress systems is still sparse, and results are heterogeneous. The current study examined the effect of an internet-based intervention for MDD on salivary cortisol and alpha-amylase as well as hair cortisol concentrations. Moreover, the prescriptive capacity of pre-intervention cortisol and alpha-amylase concentrations on treatment response was explored.

METHODS

Thirty-eight participants suffering from mild to moderate MDD collected saliva and hair samples throughout the intervention. Biological outcome parameters were salivary cortisol and alpha-amylase (awakening response, total diurnal output, diurnal slope) and hair cortisol concentrations. Treatment response was indicated by change in depression severity and perceived chronic stress.

RESULTS

Treatment response on depression scores or chronic stress was not associated with changes in any of the cortisol or alpha-amylase parameters. Exploratory analysis indicated that non-responders showed a steeper alpha-amylase slope pre-intervention.

DISCUSSION

The results indicate that changes in depressive symptoms did not correspond to changes of the biological stress systems, contradicting the suggested normalization of dysregulated hypothalamic-pituitary-adrenal axis or autonomic nervous system activity through a psychotherapeutic intervention. However, the results point to a potential role of pre-intervention alpha-amylase slope as a prescriptive marker of treatment response for depression.

Using Heart Rate Variability Methods for Health-Related Outcomes in Outdoor Contexts: A Scoping Review of Empirical Studies

Heart rate variability (HRV) is a psychophysiological variable that is often used in applied analysis techniques to indicate health status because it provides a window into the intrinsic regulation of the autonomic nervous system. However, HRV data analysis methods are varied and complex, which has led to different approaches to data collection, analysis, and interpretation of results. Our scoping review aimed to explore the diverse use of HRV methods in studies designed to assess health outcomes in outdoor free-living contexts. Four database indexes were searched, which resulted in the identification of 17,505 candidate studies. There were 34 studies and eight systematic reviews that met the inclusion criteria. Just over half of the papers referenced the 1996 task force paper that outlined the standards of measurement and physiological interpretation of HRV data, with even fewer adhering to recommended HRV recording and analysis procedures. Most authors reported an increase in parasympathetic (n = 23) and a decrease in systematic nervous system activity (n = 20). Few studies mentioned methods-related limitations and challenges, despite a wide diversity of recording devices and analysis software used. We conclude our review with five recommendations for future research using HRV methods in outdoor and health-related contexts.

Intervention methods for improving reduced heart rate variability in patients with major depressive disorder: A systematic review and meta-analysis

INTRODUCTION

Several studies have demonstrated that patients with major depressive disorder (MDD) commonly show reductions in heart rate variability (HRV) parameters. Thus, interventions for the improvement of low HRV may be advantageous in treating MDD. This systematic review and meta-analysis aimed to explore the improvement effects of current clinical treatments on low HRV in patients with MDD.

METHODS

Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the PubMed, EMBASE, PsycINFO, and CNKI databases were searched for relevant literature. Interventional studies of patients with confirmed MDD, which included baseline and post-intervention data and at least one HRV parameter as an outcome indicator, were included for meta-analysis.

RESULTS

Twenty-one studies were included in the review. Several studies affirmed the role of psychotherapy in improving low HRV in patients with MDD showing a significant increase in high-frequency and low-frequency power after psychotherapy in the meta-analysis. However, both pharmacotherapy studies and physiotherapy studies included in the meta-analysis showed significant heterogeneity.

LIMITATIONS

The main limitation of this study was the relatively small samples for the meta-analysis, and more high-quality randomized controlled trials in this field are wanted.

CONCLUSIONS

Psychotherapy was effective for improving low HRV in patients with MDD. However, the effect of pharmacotherapy or physical therapy on low HRV in MDD remains unclear. Regarding research methods, it is necessary to formulate and standardize operational guidelines for future HRV measurements.

Expanding the Mind-Body-Environment Connection to Enhance the Development of Cultural Humility

The unique health care needs of diverse individuals and communities are complex. To meet these needs, healthcare professionals are being called upon to alter traditional ways of thinking, perceiving, and acting in order to create more inclusive environments. Research shows that using mindsight, a process that increases both insight and empathy, can enhance an individual's mind-body-environment connection, increase self-awareness, and promote the development of cultural humility. This paper will discuss the current perspectives on the mind/body/environment connection from a Western lens that may impact the enactment of cultural humility for healthcare providers. Two evidence-based approaches, yoga and forest therapy, are recommended as effective intervention tools in fostering mindsight and cultural humility. Blending traditional cognitive learning with techniques anchored in the physical body may hold promise in supporting the development of mindsight and cultural humility in healthcare education and practice.

Heart rate variability predicts outcome of short-term psychotherapy at the workplace

The bio-psycho-social model highlights intra-individual and inter-individual interactions, including psychotherapy. The processing of these interactions within a person takes place, among others, in the central autonomic network (CAN). The CAN's autonomic output to the periphery can be indexed by heart rate variability (HRV), representing individual adaptive capacity. Further, the CAN influences the hypothalamus-pituitary-adrenal axis with its product cortisol. The aim consisted in investigating HRV and cortisol as well as their relation to symptom course in response to short-term psychotherapy. A single-arm, uncontrolled, explorative study was conducted at an outpatient psychotherapeutic consultation in the workplace offered to employees with mental or psychosomatic complaints. Questionnaires included symptoms of depression, irritation and functional impairment. Circadian profile of HRV and salivary cortisol concentrations collected pre and post short-term psychotherapeutic intervention (4-12 sessions) were assessed. Multilevel-linear mixed regressions were calculated. Out of 29 participants (mean age 42; 72% female), 24% were on sick leave from work. Cortisol concentrations were neither affected by intervention nor by symptom course. The proportion of individuals showing a vagally mediated HRV in the range of the lowest quartile assessed for age- and sex-matched healthy controls was reduced at follow-up (pre 34%, post 22%; p = .017). Higher vagally mediated HRV at baseline predicted lower symptom burden at follow-up. Thus, the results support the assumption that HRV reflects the capability of an organism to adapt and recover. Patients with reduced HRV might need additional psychotherapeutic sessions to achieve the same symptom improvements than patients with retained HRV.

Why Does Psychotherapy Work and for Whom? Hormonal Answers

The questions of for whom and why psychotherapy is effective have been the focus of five decades of research. Most of this knowledge is based on self-report measures. Following the biopsychosocial model of mental disorders, this article explores the potential of hormones in answering these questions. The literature on cortisol, oxytocin, and oestradiol in psychotherapy was systematically searched, focusing on (a) baseline hormonal predictors of who may benefit from psychotherapy and (b) hormonal changes as indicators of therapeutic change. The search was limited to depression and anxiety disorders. In sum, the findings show that, of all three hormones, the role of cortisol is most established and that both cortisol and oxytocin are implicated in psychotherapy, although a causal role is still waiting to be demonstrated. Moreover, there is a differential role of hormones in the psychotherapy of depression versus anxiety. The directions of research mapped in this article may elucidate how psychotherapy can be selected to match patients’ endocrine states and how hormonal levels can be manipulated to improve outcomes.

Nature and Mindfulness to Cope with Work-Related Stress: A Narrative Review

In recent years, work-related stress has grown exponentially and the negative impact that this condition has on people's health is considerable. The effects of work-related stress can be distinguished in those that affect workers (e.g., depression and anxiety) and those that affect the company (e.g., absenteeism and productivity). It is possible to distinguish two types of prevention interventions. Individual interventions aim at promoting coping and individual resilience strategies with the aim of modifying cognitive assessments of the potential stressor, thus reducing its negative impact on health. Mindfulness techniques have been found to be effective stress management tools that are also useful in dealing with stressful events in the workplace. Organizational interventions modify the risk factors connected to the context and content of the work. It was found that a restorative workplace (i.e., with natural elements) reduces stress and fatigue, improving work performance. Furthermore, practicing mindfulness in nature helps to improve the feeling of wellbeing and to relieve stress. In this paper, we review the role of mindfulness-based practices and of contact with nature in coping with stressful situations at work, and we propose a model of coping with work-related stress by using mindfulness in nature-based practices.

Effect of behavioral activation on time and frequency domain heart rate variability in older adults with subthreshold depression: a cluster randomized controlled trial in Thailand

BACKGROUND

Increased prevalence of depression highlights the need for effective interventions. Behavioral activation (BA), which can easily be adapted for non-clinical populations, has been the recommended treatment for depression. It is based on a model of psychopathology explaining that losses or chronically low levels of positive reinforcement yield behavioral and emotional changes in depression and that encouraging individuals to increase their engagement in reinforcing activities can improve their mood and enhance their valuable life experiences. Heart rate variability (HRV) provides indices of autonomic function related to depression, but only a few studies have investigated the effect of BA on HRV, particularly among older adults with subthreshold depression. Accordingly, we aimed to investigate the effect of BA on HRV in older adults with subthreshold depression.

METHODS

We conducted a 9-month cluster randomized controlled trial in two Health Promoting Hospitals (HPHs). Eighty-two participants were randomized into either intervention (BA with usual care) or control (usual care only) groups, with 41 participants per group. Daily step count was collected weekly during the 12-week BA intervention period, while HRV parameters, including the Standard Deviation of the Normal-to-Normal interval (SDNN), High Frequency (lnHF), Low Frequency (LF), and Low Frequency/High Frequency ratio (LF/HF), were examined at 0, 3, 6 and 9 months. Generalized Estimating Equations (GEEs) were used in the data analysis.

RESULTS

Over nine months, the intervention and control groups differed significantly in the unadjusted mean change of HRV, SDNN [7.59 ms (95% CI: 1.67, 13.50)], lnHF [0.44 ms2 (95% CI: 0.04, 0.85)], and LF [0.53 ms2 (95% CI: 0.09, 0.98)], whereas the groups did not differ significantly in LF/HF ratio [0.01 ms2 (95% CI: -0.04, 0.06)].

CONCLUSION

Our results suggest that BA may have a therapeutic effect on depression symptoms of older adults with subthreshold depression via improved HRV.

TRIAL REGISTRATION

TCTR20211019003 , thaiclinicaltrials.org, retrospectively registered on 19 October 2021.

Lifestyle Prescription for Depression with a Focus on Nature Exposure and Screen Time: A Narrative Review

Recent lifestyles changes have favored increased time in contact with screens and a parallel reduction in contact with natural environments. There is growing awareness that nature exposure and screen time are related to depression. So far, the roles of how these environmental lifestyles affect depressive symptoms and disorders have not been reviewed simultaneously. The aim of this review was to gather the literature regarding the role of nature exposure and screen time in depression. An emphasis was made on clinical samples of patients with well-defined depression and the different methodological approaches used in the field. A second goal was to suggest an agenda for clinical practice and research. Studies were included if they assessed depressive symptoms in patients with a clinical diagnosis of depression. An overview of the published literature was conducted using three scientific databases up to December 2021. Several interventions involving nature exposure have shown positive effects on depressive symptoms and mood-related measures. The most consistent finding suggests that walks in natural environments may decrease depressive symptoms in patients with clinical depression. Less researched interventions, such as psychotherapy delivered in a forest or access to natural environments via virtual reality, may also be effective. In contrast, fewer observational studies and no experimental research on screen time have been conducted in patients with clinical depression. Thus, recommendations for practice and research are also discussed. Scarce research, diverse interventions, and several methodological shortcomings prevent us from drawing conclusions in this area. More high-quality experimental research is needed to establish interventions with proven efficacy in clinical depression. At this stage, it is too early to formulate practice guidelines and advise the prescription of these lifestyles to individuals with depression. The present findings may serve as a basis to develop strategies based on nature exposure and screen time targeting clinical depression.

Effects of Altitude, Plant Communities, and Canopies on the Thermal Comfort, Negative Air Ions, and Airborne Particles of Mountain Forests in Summer

Forest bathing is considered an economical, feasible, and sustainable way to solve human sub-health problems caused by urban environmental degradation and to promote physical and mental health. Mountain forests are ideal for providing forest baths because of their large area and ecological environment. The regulatory mechanism of a mountain forest plant community in a microenvironment conducive to forest bathing is the theoretical basis for promoting physical and mental health through forest bathing in mountain forests. Based on field investigations and measurements, differences in the daily universal thermal climate index (UTCI), negative air ion (NAI), and airborne particulate matter (PM2.5 and PM10) levels in nine elevation gradients, six plant community types, and six plant community canopy parameter gradients were quantitatively analyzed. In addition, the correlations between these variables and various canopy parameters were further established. The results showed the following: (1) Altitude had a significant influence on the daily UTCI, NAI, PM2.5, and PM10 levels in the summer. The daily UTCI, NAI, PM2.5, and PM10 levels gradually decreased with the increase in altitude. For every 100 m increase in altitude, the daily UTCI decreased by 0.62 °C, the daily NAI concentration decreased by 108 ions/cm3, and the daily PM2.5 and PM10 concentrations decreased by 0.60 and 3.45 µg/m3, respectively. (2) There were significant differences in the daily UTCI, NAI, PM2.5, and PM10 levels among different plant communities in the summer. Among the six plant communities, the Quercus variabilis forest (QVF) had the lowest daily UTCI and the best thermal comfort evaluation. The QVF and Pinus tabuliformis forest (PTF) had a higher daily NAI concentration and lower daily PM2.5 and PM10 concentrations. (3) The characteristics of the plant community canopy, canopy density (CD), canopy porosity (CP), leaf area index (LAI), and sky view factor (SVF), had significant effects on the daily UTCI and NAI concentration, but had no significant effects on the daily PM2.5 and PM10 concentrations in the summer. The plant community with higher CD and LAI, but lower CP and SVF, showed a higher daily UTCI and a higher daily NAI concentration. In conclusion, the QVF and PTF plant communities with higher CD and LAI but lower CP and SVF at lower elevations are more suitable for forest bathing in the summer in mountainous forests at lower altitudes. The results of this study provide an economical, feasible, and sustainable guide for the location of forest bathing activities and urban greening planning to promote people’s physical and mental health.

Flow With Nature Treatment for Depression: Participants' Experiences

This study examined Flow with Nature (FWN) treatment, which is an integrative intervention (rehabilitation) based on eco and environmental psychology, psychotherapeutic theories and professional psychological practice. FWN is intended for depression rehabilitation with the help of social support, nature environments and FWN exercises. Exercises encourage sensing the environment, mindful awareness, psychological processing and focusing on the future. The FWN treatment proceeds in separate stages (horizon, growth and path), which emphasise nature, group (social support) and FWN exercises differently. This study focused on the experiences of the participants in the FWN treatment. Finnish adults who had been diagnosed with clinical depression took part in the FWN treatment (N = 82) and answered feedback questions (by paper, electronic questionnaire or phone discussion). Answers were analysed using theory-based content analysis. Data were collected between spring 2019 and spring 2020. The majority of the participants were women (82%) and on average 44 years old. Content analysis revealed that the participant feedback answers were in agreement with the central theoretical themes of FWN. The participants emphasised the significance of nature, social support and exercises differently. Moreover, the significance of these ingredients differed according to the stages of treatment: in the horizon stage restorative (e.g., fascination) and comprehensive nature experiences (e.g., connectedness with nature), in the growth stage social support (e.g., peer support) and in the path stage environmental self-regulation (e.g., nature as a part of life) were emphasised. These results are in accordance with the objectives of the stages and seem to support the phase-based rationale. The participants’ experiences of the key elements of the intervention, social support and nature environment were experienced mainly positively, which supports their inclusion in future intervention versions. In the future, FWN exercises should be developed to better enable participants’ possibilities for concentration and being present in the moment (mindfulness). Exercises should also be simplified to match the target group’s cognitive abilities.

Exploring the Physiological and Psychological Effects of Digital Shinrin-Yoku and Its Characteristics as a Restorative Environment

This study investigated the physiological and psychological therapeutic effects of a digital Shinrin-yoku environment constructed indoors in an urban facility as well as the characteristics of the environment that contribute to restorativeness (restorative traits). We measured the fluctuations in the physical and mental states of 25 subjects by obtaining both before–after measurements and continuous measurements while exposed to a digital Shinrin-yoku environment that reproduced visual, auditory, and olfactory elements. The results demonstrated that the parasympathetic nerve activity was significantly increased and that the heart rate was significantly decreased during the exposure compared with that during the resting state. As for mood, five of the six Profile of Mood States (POMS) scales (“Tension–Anxiety,” “Depression,” “Anger–Hostility,” “Fatigue,” and “Confusion”) were significantly decreased after the experience. In addition, psychological restorative effects were also confirmed, with a significant decrease in “negative affect” (measured using the Positive and Negative Affect Schedule (PANAS)) and a significant increase in the sense of restorativeness (Restorative Outcome Scale (ROS)) after the experience. In contrast, comparing the digital Shinrin-yoku environment with the actual forest environment and the urban environment using POMS, PANAS, ROS, and Perceived Restorativeness Scale (PRS), the psychological effects and environmental traits of the digital Shinrin-yoku were found to be considerably similar to those of the actual forest environment.

Factors Influencing the Visit to the Courtyard Gardens in Public Hospitals in Malaysia

Individuals mental health and well-being are significantly influenced by being in a natural setting and viewing nature. Hospital courtyard gardens (HCG) is a common feature found in public hospitals in Malaysia. Nevertheless, the factors influencing the visitation and non-visitation to the HCG are less understood. This study attempts to investigate factors influencing the visit and non-visitation of patients, staff and visitors to the HCGs in three Malaysian public hospitals. The research findings are instrumental to the architects and landscape architects to make necessary improvements for future HCG design and the hospital managers to enhance and retrofit the existing HCG.

The Value of Nature During Psychotherapy: A Qualitative Study of Client Experiences

Nature is considered to have restorative qualities that can potentially improve psychotherapy success. However, little is known about how clients experience nature during psychotherapy. The research aim of this phenomenological qualitative study was to study how clients experience nature during individual outpatient psychotherapy that took place while walking in nature. More specifically we were interested in clients’ inner world experiences. All participants (N = 12) received treatment through licensed therapists for a DSM-5 classified disorder. Semi-structured interviews were conducted. To uncover true lived experiences during these interviews, participants were asked to close their eyes and envision themselves during a psychotherapy session in nature. The verbatim transcripts were coded by means of inductive thematic analysis and the results were member checked. Results showed that nature brings clients closer to their inner worlds. How nature brings this about is unfolded in a conceptual model of lived experience. We argue that psychotherapy can be enriched by considering nature as a supportive environment because bringing clients closer to their inner worlds is of essential value in facilitating successful treatment interventions.

A Qualitative Study Comparing Mindfulness and Shinrin-Yoku (Forest Bathing): Practitioners’ Perspectives

The boundary between mindfulness and forest bathing, two conceptually related therapies, is unclear. Accordingly, this study reports the strengths and challenges, similarities and differences, and barriers and facilitators for both. Semi-structured interviews were conducted with seven trained and experienced practitioners of both mindfulness and forest bathing. Reflexive thematic analysis revealed four main themes: (i) differences between the approaches; (ii) the benefits of forest bathing; (iii) biophilia through forest bathing; and (iv) inward versus outward attentional focus as a distinction between the approaches. Both practices were found to benefit well-being, but practitioners revealed key barriers to mindfulness. For vulnerable groups experiencing mental health challenges or difficulties achieving a meditative state, mindfulness may introduce well-being risks. By offering a gentler, more intuitive approach that encourages outward attentional focus, forest bathing was found to overcome this barrier. Forest bathing is suitable for all groups, but adaptations are recommended for those expressing fear or discomfort in forested environments. The findings inform how to position both approaches in practice, as a first step towards social prescribing recommendations. Wider implications concern forest bathing’s potential to impact environmental well-being. Future research must garner comparative data, involve young people, and explore the feasibility of a forest bathing social prescription.

Reduction of depressive symptoms during inpatient treatment is not associated with changes in heart rate variability

Vagally mediated heart rate variability (HRV) is a psychophysiological indicator of mental and physical health. Limited research suggests there is reduced vagal activity and resulting lower HRV in patients with Major Depressive Disorder (MDD); however little is actually known about the association between HRV and symptoms of depression and whether the association mirrors symptom improvement following psychotherapy. The aim of this study was to investigate the association between antidepressant therapy, symptom change and HRV in 50 inpatients (68% females; 17–68 years) with a diagnosis of MDD. Severity of depressive symptoms was assessed by self-report (Beck Depression Inventory II) and the Hamilton Rating Scale of Depression. Measures of vagally mediated HRV (root mean square of successive differences and high-frequency) were assessed at multiple measurement points before and after inpatient psychotherapeutic and psychiatric treatment. Results showed an expected negative correlation between HRV and depressive symptoms at intake. Depressive symptoms improved (d = 0.84) without corresponding change in HRV, demonstrating a de-coupling between this psychophysiological indicator and symptom severity. To our knowledge, this study is the first to examine an association between HRV and depressive symptoms before and after psychotherapy. The observed de-coupling of depression and HRV, and its methodological implications for future research are discussed.

Waterfall Forest Environment Regulates Chronic Stress via the NOX4/ROS/NF-κB Signaling Pathway

Background: Forest therapy has been proven to have beneficial effects on people with depression and anxiety. However, it remains unknown whether the waterfall forest environment (WF) affects the physical and psychological health of patients with chronic fatigue and how the WF regulates chronic stress. Methods: Twenty-four patients with chronic fatigue were randomly divided into two groups: the WF group and the urban (U) group. Scores on the Hamilton Anxiety Scale (HAMA), Hamilton Depression Scale (HAMD), and Fatigue Scale-14 (FS-14) were evaluated before and after environmental intervention. Detection of physiological indexes and inflammatory factor levels and immunological analysis were also performed. In addition, the chronic stress rat model was constructed, and the effects of the WF on hopelessness and liver damage of rats were investigated. Results: Patients with chronic fatigue in the WF group showed a significant decrease in FS-14, HAMA, and HAMD scores compared with the U group. The expression levels of glutathione peroxidase and superoxide dismutase were remarkably higher in the WF group than in the U group. However, the expression levels of malondialdehyde and inflammatory factors (IL-1β, TNF-α, IL-6, and IL-10) were remarkably decreased after the intervention of the WF. In addition, animal experiments confirmed that the WF improved hopelessness, liver damage, and excitability of neurons of chronic stress rats. Mechanistically, the WF reduced the liver damage caused by chronic stress in rats by inhibiting the NOX4/ROS/NF-κB signaling pathway. Conclusions: Collectively, the WF had a positive effect on immune enhancement and physical and psychological health in patients with chronic fatigue and might inhibit chronic stress by regulating the NOX4/ROS/NF-κB signaling pathway.

The potential synergistic effects between psychedelic administration and nature contact for the improvement of mental health

Therapeutic psychedelic administration and contact with nature have been associated with the same psychological mechanisms: decreased rumination and negative affect, enhanced psychological connectedness and mindfulness-related capacities, and heightened states of awe and transcendent experiences, all processes linked to improvements in mental health amongst clinical and healthy populations. Nature-based settings can have inherently psychologically soothing properties which may complement all stages of psychedelic therapy (mainly preparation and integration) whilst potentiating increases in nature relatedness, with associated psychological benefits. Maximising enhancement of nature relatedness through therapeutic psychedelic administration may constitute an independent and complementary pathway towards improvements in mental health that can be elicited by psychedelics.

Effects of Shinrin-Yoku (Forest Bathing) and Nature Therapy on Mental Health: a Systematic Review and Meta-analysis

Shinrin-yoku, immersing oneself in nature using one’s senses, has been receiving increased attention internationally. While most of the existing studies have focused on physical health, this systematic review and meta-analysis examined the mental health impacts of shinrin-yoku, using the PRISMA guidelines (PROSPERO registry: BLINDED). Of 497 articles retrieved on databases including PubMed/MEDLINE, PsycINFO, Science Direct and Google Scholar, twenty met the inclusion criteria. All studies were conducted in Asia and Europe, and used a variety of different bathing approaches (e.g. breathing, walking, yoga). While noting a need for more rigorous research and extensive follow-up assessments, the findings indicate that shinrin-yoku can be effective in reducing mental health symptoms in the short term, particularly anxiety. More careful examination of shinrin-yoku practices is needed; longer follow-up with participants from a range of countries along with greater examination of potential mechanisms is needed for shinrin-yoku to be accepted into mainstream interventions.

Implementing Mobile HRV Biofeedback as Adjunctive Therapy During Inpatient Psychiatric Rehabilitation Facilitates Recovery of Depressive Symptoms and Enhances Autonomic Functioning Short-Term: A 1-Year Pre-Post-intervention Follow-Up Pilot Study

OBJECTIVE

New treatment options for depression are warranted, due to high recurrence rates. Recent research indicates benefits of heart rate variability biofeedback (HRVBF) on symptom recovery and autonomic functioning in depressed individuals. Slow-paced breathing-induced amplification of vagus nerve activity is the main element of HRVBF. Thus, the latter represents a safe and non-invasive complementary depression treatment. However, its efficacy in patients undergoing inpatient psychiatric rehabilitation receiving highly comprehensive treatments has not been evaluated.

METHODS

Ninety-two inpatients were randomly assigned to an intervention group (IG) or control group (CG). While the latter received the standard treatment only, adjunctive HRVBF was provided to the IG over 5 weeks. Depression severity and heart rate variability (HRV) were assessed before (pre) and after 5 weeks (post). Moreover, 1-year follow-up depression scores were available for 30 participants.

RESULTS

Although depression improved in both groups, the IG exhibited significantly larger improvements at post-assessment ( η p 2 = 0.065) and significant increases in resting LF-HRV (d = 0.45) and cardiorespiratory coherence (d = 0.61). No significant effects for RMSSD, SDNN, HF-HRV, or HR were found (ps > 0.05). Additionally, the IG showed a medium- to large-sized reduction in resting respiratory rate from 13.2 to 9.8 breaths per minute (p < 0.001, d = 0.86), with the CG exhibiting only a small decrease from 13.5 to 12.4 (p = 0.49; d = 0.35). While the IG exhibited significantly lower depression scores at post-assessment (p = 0.042, d = 0.79), this effect decreased during follow-up (p = 0.195, d = 0.48).

CONCLUSION

HRVBF as adjuvant therapy during inpatient psychiatric rehabilitation facilitated depression recovery. Additionally, amplified LF-HRV as well as cardiorespiratory coherence at rest and a decrease in resting breathing frequency was observed in the HRVBF group. These findings emphasize HRVBF's value as complementary therapy regardless of concurrent treatments. Moreover, these incremental benefits could serve as resource even after the actual training period. However, the additional antidepressant gains vanish during the long-term follow-up, indicating the need for more intense training or regular practice afterward, respectively. Thus, future studies are warranted to examine how the initial benefits of HRVBF during inpatient psychiatric rehabilitation can be preserved post discharge.

Effect of Viewing Video Representation of the Urban Environment and Forest Environment on Mood and Level of Procrastination

A common problem among students is the problem of delaying important work activities, which is conceptualized as procrastination. Since procrastination can cause considerable costs for society, we would like to find a method to effectively alleviate the symptoms of this conditioning. It has been proven in an earlier study that staying in the forest environment increases vitality and reduces anxiety, and the negative state of these features can be associated with the intensification of procrastination symptoms. Therefore, it is likely that watching a forest video may decrease the probability or intensity of procrastination. To measure the impact of the forest environment on the level of procrastination of the subjects, a randomized experiment was carried out, in which the subjects watched in random order (on different days) one of two 15-min videos: one showing a walk in the forest area and one showing a walk in an urban environment (control). We measured the level of so-called 'fluid procrastination' including three aspects: 'lack of energy to do the work', 'inability to get to work' and 'pessimistic attitude to do the work' with a set of questions the respondents completed before and after the experiment. The results showed that one aspect of fluid procrastination ('pessimistic attitude to do the work') can be effectively lowered by watching a video showing the forest environment. In contrast, watching a video of an urban environment increased the procrastination levels for two other aspects of procrastination ('lack of energy to do the work', 'inability to get to work'). We also measured three other parameters before and after the experiment: mood state, restoration and vitality. Watching the video from forest area raised mood and restoration and watching the video from urban area, decreased mood, vitality and restoration. The study suggests that watching a video showing forest landscapes could be used as an effective remedy for problems related to procrastination among students.

Urban Trees and Human Health: A Scoping Review

The urban forest is a green infrastructure system that delivers multiple environmental, economic, social and health services, and functions in cities. Environmental benefits of urban trees are well understood, but no review to date has examined how urban trees affect human health. This review provides a comprehensive summary of existing literature on the health impacts of urban trees that can inform future research, policy, and nature-based public health interventions. A systematic search used keywords representing human health, environmental health, and urban forestry. Following screening and appraisal of several thousand articles, 201 studies were conceptually sorted into a three-part framework. Reducing Harm, representing 41% of studies, includes topics such as air pollution, ultraviolet radiation, heat exposure, and pollen. Restoring Capacities, at 31%, includes attention restoration, mental health, stress reduction, and clinical outcomes. Building Capacities, at 28%, includes topics such as birth outcomes, active living, and weight status. The studies that were reviewed show substantial heterogeneity in purpose and method yet indicate important health outcomes associated with people’s exposure to trees. This review will help inform future research and practice, and demonstrates why urban forest planning and management should strategically promote trees as a social determinant of public health.

Benefits of a Three-Day Bamboo Forest Therapy Session on the Physiological Responses of University Students

Studies have indicated that natural environments have the potential to improve the relationship between a stressful life and psychological well-being and physical health. Forest therapy has recently received widespread attention as a novel solution for stress recovery and health promotion. Bamboo is an important forest type in many countries, especially in East and Southeast Asia and in African countries. Bamboo is widespread throughout southwestern China. Empirical field research on the physiological effects of bamboo forest therapy is currently lacking. To explore the benefits of bamboo forest therapy on the physiological responses of university students, 120 university volunteers between the ages of 19 and 24 participated in this study (60 males and 60 females) and were randomly divided into four groups of equal size (15 males and 15 females in each). Four sites were selected for the experiment, including two natural bamboo forests (YA and YB), a bamboo forest park (DJY), and an urban environment (CS). During the testing period, all participants were asked to view the landscape for 15 min in the morning and then walk in the testing area for 15 min in the afternoon. Blood pressure (BP), heart rate (HR), and peripheral oxygen saturation (SpO2) were measured as the physiological indexes, and the semantic differential method (SDM) questionnaire was completed for the environmental satisfaction evaluation. The SDM for the subjective environmental evaluation differed significantly among the university students; they obtained a better environmental experience, in terms of sensory perception, atmosphere, climate, place, and space, in the bamboo forest sites. The three-day bamboo forest therapy session improved the physiological well-being of university students. First, the blood pressure and heart rate of the university students decreased, and the SpO2 increased, after the three-day viewing and walking activities of the three-day bamboo forest therapy session. The viewing activities had a more pronounced effect on decreased heart rate in university students. Additionally, three-day bamboo forest therapy had a positive impact on decreased systolic blood pressure and heart rate in the university students, and it was significantly decreased in females, while peripheral oxygen saturation (SpO2) remained relatively low. Finally, compared with the urban site (CS), the bamboo forest sites effectively improved the university students’ physiological state of health, decreased their physical pressure, and stabilized their physiological indicators. These findings provide scientific evidence that a three-day bamboo forest therapy session can increase positive physiological responses. The potential for a longer-term effect on human physiological health requires further investigation.

Benefits of A Three-Day Bamboo Forest Therapy Session on the Psychophysiology and Immune System Responses of Male College Students

Forest therapy is a fast-growing treatment approach, as it has the potential to alleviate stressful life events and to improve psychological well-being and physical health. Bamboo forests are widespread in southwestern China. Nevertheless, a knowledge gap on the specific health benefits of bamboo forest (BF) therapy still exists. To explore the psycho-physiologic responses of participants to the effects of BF therapy, 60 male adults aged between 19 and 24, with similar healthy conditions, were selected to participate in this study. A one-group pretest–posttest design was used for the BF sites and the city site (CS) to compare the difference in the psycho-physiologic responses of participants before and after the test. Participants at the BF sites participated in a three-day bamboo forest therapy session, and those at the CS participated in a three-day urban program. Blood pressure, heart rate, and peripheral oxygen saturation were measured as the physical signs, and the profile of mood state (POMS) questionnaire was completed by the participants for the psychological evaluation. Blood was sampled, and natural killer (NK) activity, the number of NK cells, and the levels of corticosterone, granulysin, perforin, and granzyme A/B in peripheral blood lymphocytes (PBLs) were measured. All the measurements mentioned above were performed at 08:00 on the first and fourth days within the test. Results indicated that the three-day BF therapy was capable of enhancing positive mood states and also reducing negative mood states in the male participants. The blood pressure and heart rates of the male participants decreased, while the peripheral oxygen saturation increased after the three-day BF therapy session. Furthermore, BF therapy significantly increased NK activity and the number of NK cells and perforin-, granulysin-, and granzyme A/B-expressing cells and significantly decreased the corticosterone level in PBLs in the male participants. The three-day BF therapy session improved the psychological and physiological well-being and enhanced the immune functions of the male college students.

Facial Expressions of Visitors in Forests along the Urbanization Gradient: What Can We Learn from Selfies on Social Networking Services?

People’s satisfaction towards the experience in forests is one of most important feedbacks that forest park managers need to meet positive visitors’ experiences. Although the drawbacks of questionnaire methodology are obvious for data collection from self-reported scores at the landscape scale, few alternative methods have been proposed. In this study, nine urban forest parks along the urbanization gradients in three capital cities of Northeast China were targeted to investigate their visitors’ selfies from social networking services (SNS) by assessing facial expressions. A total of 935 photos with location records were obtained from the SNS platform of Sina Micro-Blog in a social hot-event of ‘Golden Week Holidays of National Day of China’ of 2017. Images were recognized by FireFace software to assess scores of neutral, happy, sad, angry, surprised, scared, disgusted, and contempt expressions. Data were ranked in descending order and analyzed by Friedman’s test, correlation analysis, and Poisson regression. Visitors in downtown-forests showed fewer negative expressions at the most northern city than at the southern most one. The negative expressions tended to be alleviated with the increasing distance of forest parks from downtown. However, when the distance reached over 10 km no geographical effect was found. Female visitors showed positive emotional expressions to urban forests while male visitors showed no response. In conclusion, using data from SNS, this study found an experience in forest park less than 10 km from the downtown of a northern city resulted in female visitors showing the most positive expressions.

A Systematic Review and Meta-Analysis of Nature-Based Mindfulness: Effects of Moving Mindfulness Training into an Outdoor Natural Setting

Research has proven that both mindfulness training and exposure to nature have positive health effects. The purpose of this study was to systematically review quantitative studies of mindfulness interventions conducted in nature (nature-based mindfulness), and to analyze the effects through meta-analyses. Electronic searches revealed a total of 25 studies to be included, examining 2990 participants. Three analyses were conducted: Nature-based mindfulness interventions evaluated as open trials (k = 13), nature-based mindfulness compared with groups in non-active control conditions (k = 5), and nature-based mindfulness compared with similar interventions but without contact with nature (k = 7). The overall combined psychological, physiological, and interpersonal effects from pre- to post-intervention were statistically significant and of medium size (g = 0.54, p < 0.001). Moderation analyses showed that natural environments characterized as forests/wild nature obtained larger numerical effects than environments characterized as gardens/parks, as did informal mindfulness compared with formal mindfulness. The small number of studies included, as well as the heterogeneity and generally low quality of the studies, must be taken into consideration when the results are interpreted. PROSPERO registration number: CRD42017065639.

Effects of forest bathing (shinrin-yoku) on levels of cortisol as a stress biomarker: a systematic review and meta-analysis

Forest bathing is a traditional practice characterized by visiting a forest and breathing its air. This review aims to investigate the effects of forest bathing on levels of salivary or serum cortisol as a stress biomarker in order to understand whether forest bathing can reduce stress. Medline/PubMed, Embase, Scopus, Web of Science, Cochrane Library, and Google Scholar were systematically searched for relevant articles. The quality of included trials was assessed following the criteria of the NIH dedicated tools. Afterwards, a qualitative and quantitative synthesis of retrieved evidence was performed. A total of 971 articles were screened; 22 of them were included in the systematic review and 8 in the meta-analysis. In all but two included studies, cortisol levels were significantly lower after intervention in forest groups if compared with control/comparison groups, or a significant pre-post reduction of cortisol levels was reported in the forest groups. The main results of the meta-analysis showed that salivary cortisol levels were significantly lower in the forest groups compared with the urban groups both before (MD = - 0.08 μg/dl [95% CI - 0.11 to - 0.05 μg/dl]; p < 0.01; I² = 46%) and after intervention (MD = - 0.05 μg/dl [95% CI - 0.06 to - 0.04 μg/dl]; p < 0.01; I² = 88%). Overall, forest bathing can significantly influence cortisol levels on a short term in such a way as to reduce stress, and anticipated placebo effects can play an important role in it. Further research is advised because of the limited available data.

[Mental health and wellbeing: The contribution of trees and forests to diverse populations in Britain]

This paper explores the potential contribution of trees and forest to the mental wellbeing of diverse populations in Britain. We use a conceptual framework that makes a distinction between three different levels of engagement: everyday life; green health promotion; and green therapeutic care. We then use researched and evaluated case studies in Britain to provide examples associated with these three levels of engagement. The case studies illustrate that practical approaches and interventions are developing rapidly in the Britain. Finally we discuss the main pathways and mechanisms that link mental health and wellbeing and trees and forests. We outline that there are limitations to the current international evidence base and call for consistent approaches within and between countries using a range of methodologies to capture the nuances of the complex relationships between trees, forests and mental health and wellbeing.

[Reviewing the psychological and physical health effects of forests]

Civilization illnesses today impact, and will impact in the future, everyday life of people, particularly in high-income countries. Consequences are loss in life expectancy, reduction of quality of life as well as rising economic loads. The positive effects of stays and visits in natural environments on human well-being are known for a long time. Particularly, there are many indications that forest stays have health-promoting effects. This narrative review of the literature presents the current state of the research on health-promoting effects of forest exposure. Forest exposure has positive health effects on the cardiovascular system, the immune system and on mood. Especially in the context of stress reduction, forest exposure seems to have positive influences. However, little can be concluded about the extent of these positive effects, as most studies work without control environment or control groups. Moreover forest exposure is often associated with physical activity which is also known to have health benefits. Against the background of the positive health promoting trend further research should be carried out.

A comparative study of the physiological and psychological effects of forest bathing (Shinrin-yoku) on working age people with and without depressive tendencies

BACKGROUND

In recent years, many of Japanese workers have complained of fatigue and stress, considering them as risk factors for depression. Studies have found that "forest bathing" (Shinrin-yoku) has positive physiological effects, such as blood pressure reduction, improvement of autonomic and immune functions, as well as psychological effects of alleviating depression and improving mental health. In this study, we investigate the physiological and psychological effects of "forest bathing" on people of a working age with and without depressive tendencies.

METHODS

We conducted physiological measurements and psychological surveys before and after forest bathing with subjects who participated in day-long sessions of forest bathing, at a forest therapy base located in Hiroshima Prefecture. After excluding severely depressed individuals, the participants were classified into two groups: those with depressive tendencies (5 ≤ K6 ≤ 12) and those without depressive tendencies (K6 < 5) for comparative study. The evaluation indices measured were systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse rate (PR), autonomic functions, and profile of mood states (POMS).

RESULTS

Of the 155 participants, 37% had depressive tendencies, without any differences observed between males and females. All participants showed significant decrease in SBP, DBP, and in negative POMS items after a forest bathing session. Before the session, those with depressive tendencies scored significantly higher on the POMS negative items than those without depressive tendencies. After forest bathing, those with depressive tendencies demonstrated significantly greater improvement in many of POMS items than those without depressive tendencies, and many of them no longer differed between those with and without depressive tendencies.

CONCLUSIONS

Examining the physiological and psychological effects of a day-long session of forest bathing on a working age group demonstrated significant positive effects on mental health, especially in those with depressive tendencies. Not applicable; this is not a report of intervention trial.

Immersive Nature-Experiences as Health Promotion Interventions for Healthy, Vulnerable, and Sick Populations? A Systematic Review and Appraisal of Controlled Studies

In this systematic review, we summarized and evaluated the evidence for effects of, and associations between, immersive nature-experience on mental, physical, and social health promotion outcomes. Immersive nature-experience was operationalized as non-competitive activities, both sedentary and active, occurring in natural environments removed from everyday environments. We defined health according to the World Health Organization's holistic and positive definition of health and included steady-state, intermediate, and health promotion outcomes. An electronic search was performed for Danish, English, German, Norwegian, and Swedish articles published between January 2004 and May 2017. Manual approaches, e.g., bibliographies from experts, supplemented the literature search. Data were extracted from 461 publications that met the inclusion criteria. To assess the status and quality of the evidence for health promotion effects of immersive nature-experience, we focused on the subset of studies based on controlled designs (n = 133). Outcome level quality of the evidence was assessed narratively. Interventions most often involved adventure-based activities, short-termed walking, and seated relaxation in natural environments. We found positive effects on a range of health promotion outcomes grouped under psychological wellbeing (n = 97; ≈55% positive; ≈13% mixed; ≈29% non-significant; 2% negative); psychosocial function (n = 67; ≈61% positive; ≈9% mixed; ≈30% non-significant); psychophysiological stress response (n = 50; ≈58% positive; ≈18% mixed; ≈24% non-significant), and cognitive performance (n = 36; ≈58% positive; ≈6% mixed; ≈33% non-significant; 3% negative); and social skills and relationships (n = 34; ≈70% positive; ≈7% mixed; ≈22% non-significant). Findings related to outcomes categorized under physical health, e.g., risk of cardiovascular disease, were less consistent (n = 51; ≈37% positive; ≈28% mixed; ≈35% non-significant). Across the types of interventions and outcomes, the quality of the evidence was deemed low and occasionally moderate. In the review, we identify, discuss, and present possible solutions to four core methodological challenges associated with investigating immersive nature-experience and health outcomes: (1) intervention and program complexity; (2) feasibility and desirability of randomization; (3) blinding of participants and researchers; and (4) transferability and generalizability. The results of the review have been published as a popular-scientific report and a scientific research overview, both in Danish language.

Profiles of Nature Exposure and Outdoor Activities Associated With Occupational Well-Being Among Employees

This research addresses the profiles of nature exposure and outdoor activities in nature among Finnish employees (N = 783). The profiles were formed on the bases of nature exposure at work and the frequency and type of outdoor activities in nature engaged in during leisure time. The profiles were investigated in relation to work engagement and burnout. The latent profile analysis identified a five-class solution as the best model: High exposure (8%), Versatile exposure (22%), Unilateral exposure (38%), Average exposure (13%), and Low exposure (19%). An Analysis of Covariance (ANCOVA) was conducted for each well-being outcome in order to evaluate how the identified profiles related to occupational well-being. Participants with a High, Versatile, or Unilateral exposure profile reported significantly higher work engagement in the dimensions of vigor and dedication than did the participants with a Low exposure profile. The participants with the High exposure profile also reported lower burnout in the dimensions of cynicism and professional inadequacy than the participants with the Low exposure profile. Nature exposure during the workday and leisure time is an under researched but important aspect in promoting occupational well-being.

Internal Consistency of the SF-6D as a Health Status Index in the Brazilian Urban Population

OBJECTIVES

To investigate the internal consistency of the SF-6D as a health status index in the Brazilian urban population.

STUDY DESIGN

Cross-sectional population based study.

METHODS

Five thousand individuals, older than the age of 15, were assessed in the five regions of the country. Two different methods of scoring the SF-6D where compared: "weighting the items" of the questionnaire through the Brazilian official weight coefficients, and "unweighting the items" through a parallel non preference scoring rule solely based on patients' answers to SF-6D health classification system (SF-6D_HSI). Principal component factor analysis was used for the development of the SF-6D_HSI. Pearson's, Spearman's, and intraclass correlation coefficients were used to assess the psychometric properties.

RESULTS

The SF-6D_HSI scoring formula summarized the pattern of factor loadings and the item-internal consistency (Cronbach's α = 0.858). The scale showed good item-internal consistency, exceeding the 0.70 standard. The association between weighted and unweighted (SF-6D_HSI) scores was extremely high (Spearman's ρ = 0.971). The correlations of the SF-6D_HSI with the Physical Component of the 12-Item Short-Form Health Survey (SF-12) and the Health Assessment Questionnaire was moderate to strong. The intraclass correlation coefficient obtained (0.917) also suggested that the concordance between the weighted and unweighted score distributions was prominent.

CONCLUSIONS

A nonweighted approach to score the SF-6D provides a reliable global measure of health status. The SF-6D health classification system is useful for assessing quality of life in a large and representative sample of the Brazilian population.

Adding HRV biofeedback to psychotherapy increases heart rate variability and improves the treatment of major depressive disorder

Heart rate variability (HRV) is a significant marker of health outcomes with decreased HRV predicting increased disease risk. HRV is decreased in major depressive disorder (MDD) but existing treatments for depression do not return heart rate variability to normal levels even with successful treatment of depression. Heart rate variability biofeedback (HRVB) increases heart rate variability but no studies to date have examined whether combining HRVB with psychotherapy improves outcome in MDD treatment. The present study used a randomized controlled design to compare the effects of HRVB combined with psychotherapy on MDD relative to a psychotherapy treatment as usual group and to a non-depressed control group. The HRVB+psychotherapy group showed a larger increase in HRV and a larger decrease in depressive symptoms relative to the other groups over a six-week period, whereas the psychotherapy group only did not improve HRV. Results support the supplementation of psychotherapy with HRVB in the treatment of MDD.

Beyond the Normalized Difference Vegetation Index (NDVI): Developing a Natural Space Index for population-level health research

BACKGROUND

Natural spaces can provide psychological benefits to individuals, but population-level epidemiologic studies have produced conflicting results. Refining current exposure-assessment methods is necessary to advance our understanding of population health and to guide the design of health-promoting urban forms.

OBJECTIVES

The aim of this study was to develop a comprehensive Natural Space Index that robustly models potential exposure based on the presence, form, accessibility, and quality of multiple forms of greenspace (e.g., parks and street trees) and bluespace (e.g., oceans and lakes).

MATERIAL AND METHODS

The index was developed for greater Vancouver, Canada. Greenness presence was derived from remote sensing (NDVI/EVI); forms were extracted from municipal and private databases; and accessibility was based on restrictions such as private ownership. Quality appraisals were conducted for 200 randomly sampled parks using the Public Open Space Desktop Appraisal Tool (POSDAT). Integrating these measures in GIS, exposure was assessed for 60,242 postal codes using 100- to 1,600-m buffers based on hypothesized pathways to mental health. A single index was then derived using principal component analysis (PCA).

RESULTS

Comparing NDVI with alternate approaches for assessing natural space resulted in widely divergent results, with quintile rankings shifting for 22-88% of postal codes, depending on the measure. Overall park quality was fairly low (mean of 15 on a scale of 0-45), with no significant difference seen by neighborhood-level household income. The final PCA identified three main sets of variables, with the first two components explaining 68% of the total variance. The first component was dominated by the percentages of public and private greenspace and bluespace and public greenspace within 250m, while the second component was driven by lack of access to bluespace within 1 km.

CONCLUSIONS

Many current approaches to modeling natural space may misclassify exposures and have limited specificity. The Natural Space Index represents a novel approach at a regional scale with application to urban planning and policy-making.

Nature Contact and Human Health: A Research Agenda

BACKGROUND

At a time of increasing disconnectedness from nature, scientific interest in the potential health benefits of nature contact has grown. Research in recent decades has yielded substantial evidence, but large gaps remain in our understanding.

OBJECTIVES

We propose a research agenda on nature contact and health, identifying principal domains of research and key questions that, if answered, would provide the basis for evidence-based public health interventions.

DISCUSSION

We identify research questions in seven domains: a) mechanistic biomedical studies; b) exposure science; c) epidemiology of health benefits; d) diversity and equity considerations; e) technological nature; f) economic and policy studies; and g) implementation science.

CONCLUSIONS

Nature contact may offer a range of human health benefits. Although much evidence is already available, much remains unknown. A robust research effort, guided by a focus on key unanswered questions, has the potential to yield high-impact, consequential public health insights. https://doi.org/10.1289/EHP1663.

Shinrin-Yoku (Forest Bathing) and Nature Therapy: A State-of-the-Art Review

Background: Current literature supports the comprehensive health benefits of exposure to nature and green environments on human systems. The aim of this state-of-the-art review is to elucidate empirical research conducted on the physiological and psychological effects of Shinrin-Yoku (or Forest Bathing) in transcontinental Japan and China. Furthermore, we aim to encourage healthcare professionals to conduct longitudinal research in Western cultures regarding the clinically therapeutic effects of Shinrin-Yoku and, for healthcare providers/students to consider practicing Shinrin-Yoku to decrease undue stress and potential burnout. Methods: A thorough review was conducted to identify research published with an initial open date range and then narrowing the collection to include papers published from 2007 to 2017. Electronic databases (PubMed, PubMed Central, CINAHL, PsycINFO and Scopus) and snowball references were used to cull papers that evaluated the use of Shinrin-Yoku for various populations in diverse settings. Results: From the 127 papers initially culled using the Boolean phrases: “Shinrin-yoku” AND/OR “forest bathing” AND/OR “nature therapy”, 64 studies met the inclusion criteria and were included in this summary review and then divided into “physiological,” “psychological,” “sensory metrics” and “frameworks” sub-groups. Conclusions: Human health benefits associated with the immersion in nature continue to be currently researched. Longitudinal research, conducted worldwide, is needed to produce new evidence of the relationships associated with Shinrin-Yoku and clinical therapeutic effects. Nature therapy as a health-promotion method and potential universal health model is implicated for the reduction of reported modern-day “stress-state” and “technostress.”.

The Effects of a Campus Forest-Walking Program on Undergraduate and Graduate Students' Physical and Psychological Health

We conducted a campus forest-walking program targeting university and graduate students during their lunchtime and examined the physical and psychological effects of the program. We utilized a quasi-experimental design with a control group and a pretest–posttest design. Forty-seven men (M = 25.5 ± 3.8 years) and 52 women (M = 23.3 ± 4.3 years) volunteered to participate (experimental group n = 51, control group n = 48). The intervention group participated in campus forest-walking program once a week for six weeks; they were also asked to walk once a week additionally on an individual basis. Additionally, participants received one lecture on stress management. Post-tests were conducted both just after the program ended and three months after. A chi-square test, t-test, and repeated measures analysis of variance were used to evaluate the effects of the program. Health promoting behaviors (F = 7.27, p = 0.001, ES = 0.27) and parasympathetic nerve activity (F = 3.69, p = 0.027, ES = 0.20) significantly increased and depression (F = 3.15, p = 0.045, ES = 0.18) significantly decreased in the experimental group after the intervention compared to the control group. In conclusion, using the campus walking program to target students during their lunchtime is an efficient strategy to promote their physical and psychological health.

The Salutary Influence of Forest Bathing on Elderly Patients with Chronic Heart Failure

<b/> The aim of the current study was to test the hypothesis that forest bathing would be beneficial for elderly patients with chronic heart failure (CHF) as an adjunctive therapy. Two groups of participants with CHF were simultaneously sent to the forest or an urban control area for a four-day trip, respectively. Subjects exposed to the forest site showed a significant reduction of brain natriuretic peptide (BNP) in comparison to that of the city group and their own baseline levels. The values for the cardiovascular disease related pathological factors, including endothelin-1 (ET-1), and constituents of the renin-angiotensin system (RAS), including renin, angiotensinogen (AGT), angiotensin II (ANGII), and ANGII receptor type 1 or 2 (AT1 or AT2) in subjects exposed to the forest environment were lower than those in the urban control group. Obviously, a decreased level of inflammatory cytokines and improved antioxidant function was observed in the forest group rather than in the city group. The assessment of the profile of mood states (POMS) indicated that the negative emotional mood state was alleviated after forest bathing. As anticipated, a better air quality in the forest site was observed according to the detection of PM_2.5 (particulate matter <2.5 μm) and negative ions. These results provided direct evidence that forest bathing has a beneficial effect on CHF patients, and thus may pave the way for potential development of forest bathing as an effective adjunctive therapy on cardiovascular disorders.