Implementing nature walking groups in mental health services as a transdiagnostic approach to promote recovery: a study ​protocol for a non-randomised trial

Abstract

Background

Australia is currently facing substantial challenges due to the increasing prevalence of mental health disorders, which pose significant burden on the healthcare system. Nature-based interventions such as Nature Walking Groups (NWGs) have been identified as effective interventions for improving mental health outcomes. However, they are rarely provided in Australian mental health services. Therefore, the implementation and evaluation of NWGs within mental health services in Australia is required.

Method

This research will employ a mixed-method design based on the RE-AIM framework to assess the impact of NWGs on mental health. The study will be conducted in two Australian mental health services: in Orange and Wollongong, both located in New South Wales. Three groups of participants will be recruited: (1) walking group, or intervention (n = 40), (2) non-walking group, or control (n = 40), and (3) NWG facilitators (n = 10). A total of four NWGs over 12 months will be conducted in the two sites by the trained NWG facilitators. Intervention participants will participate in one NWG, receiving 1 h per week in nature for a continuous period of 12 weeks (twelve walks per participant), while still also receiving treatment as usual (TAU). On each walk, facilitators will draw participant attention to one of the natural features and guide participants through stress reduction and mindfulness activities, lasting 3 to 10 min in duration. The control group will continue to receive TAU. Data will be collected at baseline, post-intervention, and at a 3-month follow-up, including salivary cortisol and Dehydroepiandrosterone (DHEA) tests. Ethnographic observations, semi-structured interviews, and member-checking post analysis will be employed.

Discussion

NWGs could open a new horizon in improving mental health outcomes, however, the impact and the benefits of a NWG specific to the community mental health setting is limited in Australian context. This trial will investigate the implementation and impact of walking and engaging with nature for participating consumers in two Australian community mental health services which will inform healthcare delivery.

Trial registration

Australia and New Zealand Clinical Trial Registry (ANZCTR) registration number: ACTRN12624000733572, 14 June, 2024 with protocol V.2. The ANZCTR adheres to all items from the World Health Organization Trial Registration Data Set.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-025-13135-4.

Background

Mental health conditions are a major public health problem, contributing to at least 18% of the global disease burden, with projected annual global costs expected to reach $6 trillion by 2030 [1]. In Australia, 8.7 million people between the ages of 16 and 85 (45% of the population are in this age range) will experience mental illness at some stage in their lives [2]. Mental illness and substance misuse are the second largest contributor (23%) of the non-fatal burden of disease in Australia [3] with $12,174 M being spent on mental health in 2021–2022 [4]. Given the prevalence and significant societal and financial burdens of mental illness, it is imperative to prioritize the availability and efficacy of mental health interventions.

There has been a growing interest in nature-based interventions, such as Nature Walking Groups (NWG), to prevent and address mental health symptoms [5]. Nature-based interventions have been shown to reduce negative mental health symptoms such as stress, anxiety and depression [5–7]. Contact with nature is associated with improvements in memory, cognition, and attention [8, 9], reduction in symptoms of depression and anxiety [6, 10], lower stress levels [11, 12] and healthy sleep patterns [13]. Studies have also found that nature-based interventions such as forest bathing [14], and community gardening [15] result in greater levels of confidence, improved self-worth, happiness, feelings of safety, and sense of purpose and empowerment [13, 16–18]. Nature exposure has also been linked with a lower incidence of loneliness [19]. Furthermore, when implemented in group settings, nature-based therapies can foster social connections and mitigate feelings of loneliness [6], a significant factor affecting mental and social wellbeing [20]. In terms of financial impact and efficiency, NWG’s have the potential to provide economic relief in several health-related areas. It is a cost-effective healthcare approach that can be used as a treatment alongside pharmacological and other non-pharmacological approaches [5, 21].

People who regularly use green space (parks, gardens, bushland) and blue space (rivers, lakes, beaches) are more likely to have better mental, physical and social health than those who do not access these environments [8, 11]. However, little is known about the impact of nature contact for people with moderate and severe mental health conditions [22]. Despite the clear benefits of engaging in nature, individuals experiencing enduring mental illness and socio-economic disadvantage face multiple barriers to accessing these spaces, when compared to healthier, socio-economically advantaged individuals [23, 24]. While community-based mental health services could potentially address these barriers, there has been limited research on implementing nature-based interventions for moderate to severe mental health concerns in this context [22].

Study description

This study aims to explore the impact and the benefits of a NWG specific to the community mental health treatment setting. The study will investigate the implementation and impact of walking and engaging with nature for participating consumers in two Australian community mental health services, one rural non-government mental health service and one urban Government service. It is hypothesised that participation in the NWG is expected to lead to improvements in overall life satisfaction as well as reductions in self-reported levels of stress, anxiety, and depression. Specifically, the study aims to: (1) evaluate the implementation of structured NWGs in mental health services, (2) identify the impact of facilitated nature contact for people living with severe and persistent mental health conditions, (3) develop evidence-based guidelines for service providers to implement and evaluate NWGs supporting future implementation and research.

Methods

Study design

This study will employ a non-randomised, mixed methods design based on the RE-AIM framework to include the priorities, views and experiences of people with enduring mental illness and mental health care providers. Multiple methods of data collection and analysis will be used; including wellbeing outcome measures (pre-, post-, and 3-month follow-up measures), salivary cortisol and dehydroepiandrosterone (DHEA) testing pre-and post-intervention, ethnographic observation by a research assistant for each walking group, semi-structured interviews post-intervention, and member-checking workshops post analysis. These will be employed to determine the impact of the nature walking group intervention and identify contextual factors critical to its implementation in rural government and non-government health services.

Participating sites

The study will be conducted in two locations– Orange and Wollongong in New South Wales, Australia. Orange is classified as MMM3– rural town, and Wollongong classified as MMM1– major city (modified Monash model [25]). This will give us the opportunity to compare implementation in Non-Government Organisations and Government services and rural and urban sites. Both sites support people with enduring and severe mental illness, such as major depressive disorder, bipolar disorder, and schizophrenia with an average age of 45 years (range 18–65). Both services are near a variety of national parks and/or other green spaces.

Training workshop

Site study co-ordinators will identify and invite mental health clinicians to attend NWG facilitator training and implementation workshops. Training workshops will ensure practitioners have adequate nature-connection knowledge and skills, practical guidance on nature routine implementation processes, participant recruitment and data collection tools.

Sample

The study will have three groups of participants: (1) an intervention group, (2) a non-walking control group and (3) NWG facilitators. Participants in walking groups who are part of the intervention group are those who use the partner organizations’ mental health services at the study sites (n = 40). Non-walking group participants (n = 40) are individuals utilizing the partner organizations’ mental health service who opt out of walking groups but agree to participate in the research, and NWG facilitators (n = 10) are staff members of the partner organizations in charge of providing services and implementing the NWGs at the study sites. Forty participants will be recruited at each site (n = 80) from the mental health consumers receiving services. Approximately 100 consumers receive services at these agencies at any given time. As the control group are self-selecting, the study is non-randomised and group allocation is not blinded.

Eligibility criteria

The eligible participants will be (1) 18 years or older, (2) currently receiving mental health services at one of the study sites, and (3) showing interest and commitment to be part of a 12-week program of weekly nature walking groups. Participants in the walking groups (intervention group) have to pass the health moves assessment (see supplementary material 1). Participants must be able to walk unassisted for up to 60 min at low intensity and attend 80% of the scheduled walks. Those who currently have acute mental illness such as psychosis or suicidal ideation, will also be excluded from participation, but will be eligible for future groups. For the non-walking group (control group), participants must currently be receiving mental health services from sites in order to be eligible. They have to be either not interested in joining the nature walking groups or unable to participate because of physical health problems identified in the health moves assessment.

Recruitment

Recruitment flyers will be distributed at each of the study sites (See Supplementary Material 1). Each location will have a study co-ordinator who holds a managerial position and will provide clinicians with an overview of the study and NWGs. Clinicians can then discuss participation with existing clients on their caseload and provide them with information on the study and the contact details of the research team. Some treating clinicians will also be trained NWG facilitators, however, they will not enrol potential participants into the study or gain consent. Once all potential participants have been connected with the research team to express their interest, they will be invited to an information day conducted by research team members at each site. People who cannot attend the information session will be followed up by the research team. Potential participants will receive a Participant Information Sheet where they can learn more about the research project. Specifically, that participation in the NWG will involve: (1) completing an online or pen and paper survey at the commencement and conclusion of the 12-week session, (2) completing a brief mood question, pre- and post- each walk, (3) participating in a walk once a week for 12 weeks at a location they will be transported to, (4) participating in a 2-hour closing focus group at the 12th walk, (5) completing one phone interview with a member of the research team, and (6) providing 3 saliva samples for cortisol and DHEA testing one week before commencement, at the end of the first walk and conclusion of the last walk. Participation in saliva testing will be optional.

Intervention (walking group)

A total of two NWGs per site over 12 months will be delivered. Intervention participants (n = 40) will receive 1 h of NWG for a continuous period of 12 weeks. Participants will be transported to and from each NWG location by the NWG facilitators. There will be no expectation to socialise with other group members, but participants will be required to remain in the group. Where available, an educator such as a National Park ranger can join and refer to points of interest and answer any questions. The project funds will cover all costs of the intervention including backfill for clinicians, if required.

Nature connection routines

Each NWG will take place in a natural environment, e.g., bush, countryside, National Parks, and botanical gardens. Each walk will include two activities led by trained facilitator that draw participants’ attention to one of the natural features of the site (e.g. water, birds, plants) and provide time to reflect on those features. The activities relate to psychological theories that link connection with nature as a pathway to health and wellbeing including Attention Restoration Theory [26], and Stress Reduction Theory [27]. Each activity is 3–10 min long and is matched with the optimal kind of nature known to facilitate a particular outcome [28, 29]. The study site coordinators have chosen NatureFix routines and NWG sites for each location. Each routine will include a script for facilitators to read, or play and audio version (for example https://www.naturefix.life/feel-the-flow). Walk locations, core theme of walks, and flexible routines, routine requirements and a summary of routines are given below in Tables 1 and 2.

Table 1.

Walk locations, core theme of walks, and flexible routines, and routine requirements

			Routine requirements					Mobility needs
Walk locations	Core theme of walks	Routines	N/A	Quieter location	Sensory diversity	Natural lighting	Natural sounds	Diverse view	Sitting	Standing	Walking
e.g. Botanic gardens	Breathing routines Walks 1 & 7	Conscious breathing		x					x
		Five finger breathing		x					x
	Listening routines Walks 2 & 8	Kangaroo ears					x			x	x
		Listen up					x		x	x
	Sight routines Walks 3 & 9	Eye of an artist				x			x	x
		Focus on fractals			x			x	x	x
	Gratitude routines Walks 4 & 10	Introduce yourself to Country	x						x	x
		Thank you nature		x				x	x	x
	Immersion routines Walks 5, 6, 11 & 12	Willing smile & open hand		x					x
		Connection on the move	x								x
		Mindful moments			x				x	x

The theme of the walk and their timing of their delivery is to remain consistent. Walk locations, and which routines are used is flexible (at least x2 routines per walk is suggested). Walk locations may be repeated, changed, or kept the same

Table 2.

Summary of routines

Routine type	Routine name	Summary
Breathing Walks 1 & 7	Conscious breathing	2-4 min mindful breathing activity to become more aware of breath.
	Five finger breathing	2-4 min breathing technique that uses your fingers to take five deep breaths.
Listening Walks 2 & 8	Kangaroo ears	3-5 min activity that amplify sounds using ‘kangaroo ears’ that made by cuffed hands.
	Listen up	3-7 min activity to tune into nature sounds to decrease stress and restore focus.
Sight Walks 3 & 9	Eye of an artist	2-4 min activity that uses light and shade to appreciate the patterns and colour of nature.
	Focus on fractals	5 min activity that views the repeated patterns in nature to increase relaxation.
Gratitude Walks 4 & 10	Introduce yourself to country	3-5 min activity that introduces the benefit of acknowledging Country.
	Thank you nature	3-10 min walking activity that asks individuals to use be grateful for nature.
Immersion Walks 5, 6, 11 & 12	Willing smile & open hands	2-4 min a body posture technique to increase relaxation and decrease stress.
	Connection on the move	Access the benefits of nature whilst part of a 10 min walk.
	Mindful moments	5-10 min 5,4,3,2,1 sensory stress reduction activity.

The NSW National Parks and Wildlife Services grade publicly available walking tracks according to their difficulty (1 to 5, with 5 being the most difficult; please see supplementary materials 1 for further details on this grading). Each selected walk location will be graded between 1 and 3 (see Supplementary Materials 1).

Treatment as usual (intervention and control groups)

Participants in the intervention group will also continue to receive one-on-one support from a clinician of the multidisciplinary team at the multidisciplinary services. Similarly, those in the non-walking group will continue their TAU. The teams at each location consist of psychologists, occupational therapists, nurses, social workers and peer workers. The services work with adults (18–65 years old) experiencing varying mental illnesses to support their mental health recovery goals. These goals might revolve around social inclusion, emotional development and support, and vocational support. The sessions are tailored individually, can be held weekly or fortnightly, and can either be brief or long-term support. Clinician support generally involves the use of motivational interviewing, goal setting, problem-solving, case management and some brief cognitive behavioural therapy (CBT). The services assist consumers to develop greater clarity and understanding of their goals and how to achieve them, increase insight into the impacts of mental illness and have greater awareness of resilience factors and community resources.

Data collection tools and procedures

A variety of quantitative and qualitative data will be collected to explore the experiences and impact of NWGs for the participants.

Organisational Readiness for Implementing Change (ORIC) survey (NWG facilitators)

Prior to commencement of the first NWG, employees at each site will be invited to complete an anonymous online survey on the organisational readiness to implement the NWG. The Organizational Readiness for Implementing Change (ORIC) [30] is a valid, reliable 12-item questionnaire that assesses the extent to which organisational members are psychologically and behaviourally prepared to implement organisational change.

Ethnographic observations (intervention group)

A research assistant will participate in the walking groups and take field notes during each group. These observations are crucial because they can contribute knowledge of the setting of each group, participants’ behaviour during each walk, and reflections on the group content and/or process. In this way, the researcher is a participant observer of the walking groups [31]. The fieldnotes will include detailed descriptions and reflections for each entry and may also include theoretical and methodological observations [32]. The Ethnographic Observations Guide is attached (see Supplementary Materials 1).

Group closing reflective focus groups (intervention group)

After the last group, participants will be invited to take part in a focus group (2 h) asking participants questions such as what did you like most about NWGs? Did you experience any problems participating?. Additionally, field-notes and audio-recording will be taken during the focus group to document participants’ reflection on their journey through the program.

Facilitator interviews (NWG facilitators)

After the Nature Walking Groups have finished, NWG facilitators will be invited to participate in an individual interview about their facilitation experiences. The interviews will be conducted online on Microsoft Teams. The discussion will be audio recorded, and recordings will be professionally transcribed into word documents for analysis. Please see Supplementary Materials 1 for the interview guide.

De-identified site-wide client data

To establish the profile of the site’s client population and compare it to those participating in the intervention, the evaluation team will utilise a range of de-identified routinely collected health data. The sites will provide de-identified data to the evaluation team. Data to be extracted: (1) Number of clients serviced and their demographics (including diagnosis), (2) Referral source, (3) Intervention activities– type of intervention (e.g. case management, psychiatry), length of time engaged with service, (4) Aggregated outcome measure results.

Pre, post and 3-month follow-up surveys (intervention and control groups)

An online or pen and paper survey will be completed by participants in the intervention and control groups, prior to the groups, immediately after the last group and at 3-months post-intervention. Intervention Group participants who do not continue with the walks will be contacted by phone to arrange follow-up data collection. Three attempts to contact them will be made over a one week period before considering them lost to follow-up. The following scales (Table 3) will be included, the details of the survey scales are attached to the Supplementary Materials 1.

Table 3.

Pre, post and 3-month follow-up survey scales

Primary Outcome Measure	The Patient Health Questionnaire for Anxiety and Depression (PHQ-AD) (16 items) [33]
Secondary Outcome Measures	Personal Wellbeing Index (7 items) [34]
	Pittsburg Sleep Quality Index (2 items) [35]
	DeJong Gierveld Loneliness Scale (6 items) [20]
	Nature Relatedness Scale– short form (6 items) [36]
	The Warwick Edinburgh Mental Well Being Scale (7 items) [37]
	Major life event, positive or negative (2 items)
	Connor-Davidson Resilience Scale (2 items) [38]

Pre-post salivary cortisol and DHEA testing (intervention and control groups)

Cortisol is a widely studied biomarker frequently used as a measure of human stress levels [39, 40]. It is a steroid hormone essential for many vital processes, helping to control metabolism, fight infection, regulate blood glucose, maintain blood pressure, and plays an important role in priming the body to respond to stress. Cortisol is produced by the adrenal glands that sit on top of the kidneys and the amount of cortisol released can be influence by a variety of elements including exercise. Levels follow a daily pattern (the diurnal rhythm), rising in the early morning, peaking about 8:30 a.m. before falling in the evening [41].

Dehydroepiandrosterone (DHEA) is an adrenal androgen, a human steroid and precursor to several anabolic steroids, which is co-released with cortisol. The cortisol-DHEA ratio hypothesis maintains that DHEA has a protective function in which it counters elevated cortisol to achieve homeostasis, and hence protects the hippocampus and hypothalamic-pituitary-adrenal axis against the effects of chronic exposure to cortisol. It is considered therefore that high levels of DHEA are a good measure of resilience. A comprehensive review of the literature on cortisol and DHEA levels in mental health monitoring found that quantifying the cortisol- DHEA ratio was important for objectively measuring stress variance between mental health service consumers and healthy individuals [40].

Saliva samples will be collected from all participants by the site study co-ordinator as per the instructions of the test used (see Supplementary Material 2). To reduce the possibility of diurnal changes and other confounding variables it is envisaged that the samples will be collected between 11am and 1pm on three assigned collection days, as follows: (1) one week prior to the first walk, (2) at the conclusion of the first walk, (3) at the conclusion of the final walk (12th walk). The samples will be identified with the participant’s unique code to protect their identity before being securely stored until transported for analysis. Samples must be kept frozen at −20 C until testing as thawing and re-freezing degrades the sample (please see Supplementary Materials 2 for saliva collection procedure and handling).

Before and after walk mood scale (intervention group)

Visual single item mood scales have been shown to be both simple and quick to administer and have validity equal to other more complex and time-consuming self-rated or observe-rated scales making them a reliable measure for monitoring mood changes during research projects [42]. A visual single item mood scale typically consists of two dichotomous endpoints with a single straight line about 100 mm long. The moods at the endpoints are labelled with a numbered scale, each point represented by an emoji. Prior to each walk, the research assistant accompanying the group, will ask each participant to complete their scale before the walk, and then again after (see Supplementary Materials 1).

Phone interviews (intervention group)

Individual phone interviews will be conducted with the participants in the intervention group 3 months after the intervention ends. A semi-structured interview guide will be used (see Supplementary Materials 1); interviews will be audiotaped and transcribed. The brief interview (15–30 min) will explore any longer-term benefits for the intervention group including if they continued to walk in nature. Intervention group participants who completed three or more walks will be contacted for interviews. The interviews will be conducted by the project investigators and/or research assistants.

Data analysis

A frequentist statistical approach will be adopted for quantitative data analysis, using SPSS or R software. Specifically, analysis of variance will provide objective evidence of the efficacy of the NWG intervention.

Sample size and power calculation

While sample size calculation is crucial for any study, achieving adequate power through formal calculations can be challenging [43]. Nonetheless, we have derived the sample size for this study by considering the estimated effect size observed in the literature for various mental health indicators. According to the conceptual framework of the proposed feasibility trial study, the primary outcome measure was the level of distress measured by Patient Health Questionnaire Anxiety and Depression Scale (PHQ-ADS). In a recent randomized controlled trial study in the UK [44], it was found that the mean level of distress among the study participants was 22.76 (SD, 9.46), which decreased by 30% immediately after the cognitive behavioural therapy intervention. We utilized these study findings to inform the parameters for the sample size calculations in our study. We assumed the mean level of distress will be about 22.76 (with SD, 9.46) among the study participates at baseline in both control and interventions group [44]. After the program implementation, the mean level of distress will be reduced to 16.08 (SD, 10.41) among the participants in interventions group (assuming about 30% reduction by the intervention [44]). To ensure a minimum detectable difference in the mean distress level between the intervention and control groups at follow-up, with a power of 80% and a 5% level of significance, a minimum sample size of 72 participants is required (36 participants in each group). Anticipating 10% loss to follow-up, we plan to include 80 participants in total. Therefore, data will be collected from at least 40 participants in both the control and intervention groups, enabling to assess the program’s effectiveness in improving mental health outcomes. Our planned sample size falls within the range of suggested sample sizes for feasibility studies as per the guidelines, which recommend 30–59 participants [43, 45]. The outcomes will be analysed using a Wilcoxon signed ranks test to calculate change between scores because measures contain ordinal data and a test that does not assume a normal distribution is required. A W-statistic is appropriate for a small number of linked observations. An intention-to-treat analysis will not be conducted.

Qualitative data analysis

Qualitative data will be analysed using an inductive thematic approach [46] and managed through QSR NVivo 12 software. Thematic analysis is theoretically flexible, interpretive, and data driven, which will allow for uncovering the thoughts, perceptions, and feelings of the study participants [47]. The data analysis will focus on participant satisfaction (e.g. What did you like the most about the walking group?) as well as perceived outcomes of their involvement in the nature walking group (e.g. What do you think might be the impacts of the walking group for your mental health and wellbeing?). The team will collaboratively develop a codebook, and two researchers will code all the data sources independently and compare their results. Additional strategies such as audit trail and member checking via the final data analysis workshop will be used to ensure rigor in our analysis [48].

Member-checking workshop

A group workshop will be conducted by investigators to invite intervention, control and NWG facilitator participants to engage with the data analysis process and clarify the findings thus far. Participants who attend will receive a $50 payment for their time. During this workshop, the investigators will engage with the participants in a process called member-checking whereby the participants are invited to provide feedback on the accuracy of the data analysis [49] Specifically, participants will be asked questions along the lines of ‘After hearing about the findings, what are your general thoughts?’; ‘How accurately do you feel the findings captured your thoughts/experiences?’; ‘What could be added to the findings to more accurately capture your experiences?’; ‘Is there anything you would like removed from the data, what would that be and why?’.

Data storage and record retention

The interviews will be audio-recorded and transcribed by professional transcribing services. We will keep the outcome measures, interview audios, interview transcripts and field notes in a Charles Sturt University password-protected one drive for business folder. The interview audio records will be destroyed after 5 years, which is the minimum storage period for university research. Only the researchers and trained and approved research assistants will have access to the data. Only the persons conducting the study or the person typing the information will hear the tape. All data collected from this study will be compiled so that no individual’s statements are identifiable. The data will be owned by the Rural Health Research Institute of Charles Sturt University (see Supplementary material 3 for data management plan).

Ethics and safety

A human research ethics committee approval (H24047) has been obtained from Charles Sturt University and the Greater Western Human Research Ethics Committee (2024/ETH00561). Approval will be sought from these bodies prior to implementing any amendments to study procedures. Protocol amendments will be submitted to ANZCTR. There is a potential for participants to become mentally and/or physically unwell during the research. Firstly, the potential for mental health consumers to become acutely mentally unwell is an ever-present issue, however, it is mediated through a complex network of the person’s individual coping strategies, their daily routine, social network, and professional medical care. The risk of exacerbation of an acute episode as a direct cause of the research would be considered low, as current research suggests that both physical exertion and experiencing natural environments are stress-relieving rather than inducing. The stress-relieving benefits of engaging with the natural environment have already been discussed and outlined. As the research requires participants to be physically active, there is a small risk of physical injury. Specific walking routes will be chosen to lessen the likelihood of trips and falls to occur. As risks to participants are low and group allocation is self-selected, there are no procedures for stopping the trial or interim data monitoring. Participants dissatisfied with the intervention can stop attending at any time and this will not affect their engagement with or treatment by mental health services.

Discussion

The number of Disability-Adjusted Life Years (DALYs) worldwide attributable to mental disorders climbed from 80.8 million to 125.3 million between 1990 and 2019, while the percentage of DALYs worldwide attributable to mental disorders increased from 3.1 to 4.9% [50]. Global rapid urbanization is resulting in the emergence of novel mental health challenges [51]. Intergenerational disparity, unrestrained social media, wage theft, insecure employment, and the climate crisis are the significant contributors of mental health problems [52]. It is therefore necessary to explore alternative interventions that might complement conventional mental health treatments. Nature could serve as a promising novel alternative, with NWG’s a relatively inexpensive and environmentally sustainable mental health intervention. It is evident that walking in natural environments could be an effective strategy for preventing mental illness and promoting health. A recent systematic review revealed that nature-based interventions can reduce anxiety, stress and negative mood in clinical practice [53]. As detailed above, this study will evaluate the implementation of structured NWG in mental health services, identify the impact of facilitated nature contact on individuals with severe and persistent mental health conditions, and provide evidence-based guidelines for service providers to support future implementation and research of NWGs. To our best knowledge, this is one of the first trials in rural and regional Australia that investigates the impact of facilitated nature contact on individuals with severe and persistent mental health conditions.

This current study is robust in design because it employs a mixed-method approach, integrating physiological measures (salivary cortisol and DHEA) with qualitative data (ethnographic observations and interviews). Employing the RE-AIM framework ensures comprehensive evaluation across reach, effectiveness, and sustainability. The findings of this trial will have substantial effects on future funding and support for Nature Walking Groups that include mental health services. In addition, NWGs will be conducted at two locations in New South Wales: a rural non-governmental organization, and a regional government-operated mental health program. The dual-site approach is significant as it facilitates a comparison of outcomes across various service models, hence augmenting the generalizability and application of the findings.

Authors’ contributions

NS and JA wrote the study protocol, KO and PD planned the data collection, ZR prepared manuscript draft. All authors reviewed multiple versions and revised manuscript drafts.

Funding

Commonwealth Department of Health and Aging grant– Grant ID 4-DGEJZ1O/4-CW7UT14. The funding body has no role in study design; collection, management, analysis, and interpretation of data; writing of the report; and the decision to submit the report for publication, including no ultimate authority over any of these activities.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

A human research ethics committee approval (H24047) has been obtained from Charles Sturt University and the Greater Western Human Research Ethics Committee (2024/ETH00561). All participants will provide written consent to participate. Participation is voluntary.

Consent for publication

Not required.

Competing interests

The authors declare no competing interests.