Numerous secondary reviews exploring the link between nature and MH currently exist. We identified several reviews that have explored this link, but none have specially asked how nature impacts engagement in care, except for Masterton et al. (2020) who conducted a realist review into how and what green-care interventions offer and the benefits they provide in MH care. This does appear to focus on more regimented courses in nature though, rather than the MH catchups this review was seeking to evaluate. Cooley et al. (2020) explored talkg therapy and nature, with a focus on how this could work for psychologists. WT remains a focus for research, as seen by the included articles in this review. We read two other secondary reviews focused on WT, both only for youth participants, and courses immersing participants in nature for weeks at a time (Bettmann et al., 2016; Kraft and Cornelius-White, 2020). Other reviews located included one solely focused on blue-care interventions and the need for active engagement in this type of nature (Britton et al., 2020), one focused on how nature-based activities impact wellbeing for older adults (Gagliardi and Piccinini, 2019), and how nature-based interventions impact mental and physical health (Coventry et al., 2021). These reviews all add valuable insight to the available literature on MH care in nature but have not been able to answer the question of how care in nature enhances engagement of SUs. So, the current review extends the current evidence by reporting on which specific elements of care in nature impact engagement, and how they could enhance care.
Four studies provide evidence of notable differences between adults and youth in how nature creates a safe therapeutic space and enhances engagement. For youth, the informal and spacious nature of outdoor therapy settings consistently enhances comfort and engagement by reducing power imbalances with therapists and providing opportunities for experiential learning, autonomy, and self-regulation (Harper, 2017; James et al., 2021). These factors appear well-suited to the developmental needs and preferences of adolescents, who may be more open to novel environments and experiential learning. In contrast, the benefits of nature therapy for adults seem more variable and context dependent. While some adults may find nature therapy beneficial for wellbeing and work engagement (van den Berg & Beute, 2021), others may require specific types of outdoor spaces to engage effectively, such as the marginal, transgressive spaces preferred by adult psychiatric survivors (Laws, 2009). Adults' established attachment patterns, need for structure, and clinical presentation are likely key factors influencing the impact of nature therapy. These findings suggest that the developmental stage and clinical needs of the client are important considerations in understanding how nature creates a therapeutic space, with the impact being more consistently pronounced for youth than for adults. Future research directly comparing age groups and investigating the interaction between client characteristics and outdoor settings could enhance our understanding of the developmental factors shaping client engagement with nature-based therapies
Findings from this review suggest that nature offers therapeutic benefits as both a passive and active resource for stress management. Passive interaction involves exposure to natural scenes, sounds, and smells (Berto, 2014). It reduces physiological stress responses while enhancing mood and cognitive performance. There is evidence that watching natural environments directly or indirectly (through digital media) takes individuals’ attention from stressful situations to a more calming alternative (Berto, 2014; Björling et al., 2022; Johansson et al., 2022). For youth, this mode of therapy primarily serves as a momentary respite, who view immersive virtual nature experiences as an escape from daily stressors (Drake et al., 2021). Conversely, active engagement with nature through activities like gardening, hiking, or forest bathing delivers more profound health benefits. This interaction supports physical exercise, personal development and improved social ties (Björling et al., 2022; Bonham-Corcoran et al., 2022). Adults appear to derive greater value from the opportunity to exert control, build social connections, and engage in physical activity within natural settings (Björling et al., 2022; Bonham-Corcoran et al., 2022). Many adults attain immediate stress relief, personal growth and the development of resilient coping mechanisms (Björling et al., 2022; Bonham-Corcoran et al., 2022). This observation means that active use of nature as a therapeutic tool may be more impactful for adults compared to youth. Active nature-based interventions may play a critical role in long-term mental health and well-being, compared to the temporary relief found in passive approaches. Further research exploring this difference is needed.
Overall, the findings confirm that nature and care in nature have a positive impact on therapeutic relationships, particularly for youth participants in WT groups. These studies highlighted the power that knowing a MH care provider believes in you, when participating in nature care, has for the therapeutic relationship. This impact of nature on the therapeutic relationship enhanced engagement, and the SUs desire to connect with their MH care provider (Drake et al., 2021; Harper, 2017; Kyriakopoulos, 2011; Revell et al., 2014; Russell and Phillips-Miller, 2002). In the New Zealand-based thesis from Horn (2021) it was determined that nature had a positive impact on the therapeutic relationship, from the MH care provider point of view. Supporting this idea that nature can influence the therapeutic relationship is the work from Cooley et al. (2022) exploring barriers for care occurring in nature. They highlight the importance of both the SU and MH care provider collaborating regarding their choice of place of care, to ensure safety, which would also support the therapeutic relationship. So, therapeutic relationships and the therapeutic use of self are key components to enhanced levels of care, especially in MH, and if nature can foster them, then MH care providers should have an obligation to explore these as an option for their SU (Cooley et al., 2022; Hartley et al., 2020; Horn, 2021).
4.1 Limitations
Five of the studies were focused on youth and young adults below the age of 25. None of the studies focused on older adults. Ethnicity of participants was not available for most of the studies, and most of them were focused on developed countries (UK, USA, Canada, Australia, the Netherlands), except for one study, which considered global participants. The homogeneity of the participants could be both a strength and limitation of this review. The findings from this review would indicate that nature is beneficial for some SUs. However, if transferring findings to SUs who were not demographically included in the studies, special consideration would need to be taken to ensure the findings apply to them. Most of the studies were qualitative, with only two being mixed methods. Another bias to consider is the selection bias from some of the studies, where participants volunteered themselves to be involved, potentially skewing the results were more positively inclined toward nature. Compounding this is the point from Revell (2014) that terminology may differ globally, so the search terms used in this review may not have captured all relevant studies. Finally, the time constraints around this project due to it being a piece of academic work completed in a short time frame. Whilst a research supervisor was involved in overseeing the work, they were not directly involved in the search strategy or study selection processes, leading to potential bias from the researcher.
4.2 Implications for Mental Health Practice
The findings have several implications for mental health practice. Nature-based interventions can potentially improve engagement in care for MH service users (SUs). MH practitioners should consider incorporating nature-based interventions as an alternative or complementary approach to traditional care settings to enhance the therapeutic experience and outcomes for SUs. While the studies included in this review primarily focused on psychologists and mentors for wilderness programmes, the findings can be applied to MH practice more broadly. As Hartley et al. (2020) emphasise, SUs value the therapeutic relationships they have with MH practitioners, as these relationships are key to their progress in improving mental well-being. MH practitioners should consider incorporating nature-based interventions as an alternative setting for care, particularly for regular meetings with SUs that would traditionally occur in a clinic room. However, it is important to note that nature-based interventions may not be suitable for all types of MH care, especially when privacy and specific medical procedures are required. Practitioners should collaborate with SUs to determine the appropriateness and feasibility of nature-based interventions on a case-by-case basis, taking into account individual needs, preferences, and treatment goals.
4.3 Recommendations for Future Research
To further advance the understanding and application of nature-based interventions in MH care, several recommendations for future research can be made based on the findings of this review. First, as the review did not explicitly examine the role of MH nurses in nature-based interventions, future studies should explore how MH nurses can effectively utilise nature in their care to promote engagement. This research could provide valuable insights into the specific strategies and considerations for incorporating nature-based approaches into nursing practice. Second, while this review primarily focused on qualitative studies, with only two mixed-methods reviews, future research should employ more quantitative methodologies to measure and evaluate the impact of nature on MH engagement. Although several systematic reviews have explored blue care and green care (Britton et al., 2020; Cooley et al., 2020; Masterton et al., 2020), there is a need for more quantitative studies to provide empirical evidence for the effectiveness of nature-based interventions in enhancing SU engagement and improving MH outcomes. Third, future research should investigate the impact of nature-based interventions on specific populations, such as indigenous communities and older adults. By examining the cultural, social, and developmental factors that may influence the effectiveness and acceptability of nature-based approaches, researchers can contribute to the development of more culturally responsive and age-appropriate interventions. Finally, to strengthen the evidence base for nature-based interventions in MH care, future studies should employ more rigorous research designs, such as randomised controlled trials, to establish causal relationships between nature exposure and MH outcomes. Additionally, researchers should explore the long-term effects of nature-based interventions on SU engagement and well-being, as well as the potential mediating and moderating factors that may influence the effectiveness of these approaches.