The study was carried out by Harpa Lind Kristjánsdóttir of the Vocational Rehabilitation Center of the Westfjords, Sigrún Siguröardóttir of the University of Akureyri, and Anna María Pálsdóttir of the Swedish University of Agricultural Sciences in Alnarp. Their goal was practical: to find out which nature-assisted activities participants actually experienced as meaningful and psychologically rewarding, so that the rehabilitation centre could extend and improve the program it offers to clients working toward a return to work or education.

The scientific rationale rests on a substantial body of research showing that nature acts as a salutogenic factor, meaning it actively contributes to health and well-being rather than merely avoiding disease. Both passive exposure to natural environments, such as simply being in a green space, and active engagement, such as gardening or hiking, have been linked to improved mental health. Nature-based interventions have shown particular promise for people with depression, anxiety, and stress-related conditions, and previous Swedish studies have found that longer nature-based rehabilitation may contribute to a faster return to work. Yet, despite this international evidence base, no studies had examined nature-assisted occupations specifically within the Icelandic vocational rehabilitation context, where the landscape, climate, and culture differ markedly from the settings of earlier research.

To fill that gap, the team used a mixed-method convergent longitudinal design over one year. Eleven participants, three men and eight women aged 29 to 53 with an average age of 42, were recruited from the rehabilitation centre and took part in voluntary two-hour nature sessions each week as an add-on to their ongoing rehabilitation. Participation periods ranged from four to eleven months, averaging seven months. The activities fell into five categories: outdoor play, foraging in nature, adventure activities, outdoor gardening, and indoor gardening. Crucially, the sessions were deliberately unstructured. No goals were set for completing work, participants were free to quit mid-task, and they were even encouraged to stop without finishing projects they had started, a design choice intended to relieve the performance pressure that many people with stress-related difficulties find debilitating.

The activity calendar tracked the rhythms of the Icelandic year. In winter, participants built snow sculptures and snowmen, made snow angels, and sledged down mountainsides, carrying their sledges back up repeatedly despite fatigue. In late June they picked herbs that were dried and brewed into tea; in August they gathered bilberries eaten with cream; in October they harvested Icelandic moss, later boiled in milk as a nourishing drink; and in November, timed carefully around low tide, they collected dulse seaweed that was rinsed, baked, and eaten as a snack. Cones, birch branches, heather, and moss gathered in early November became Christmas decorations in December. Spring brought a guided kayak trip from the local sailing club, and autumn a mountain hike along a gentle marked path to a viewpoint. Outdoor gardening ran from May to September in a 300-square-metre garden beside the centre, while indoor gardening, including sowing, repotting, and propagating plants under vegetation lights, continued year-round.

Quantitatively, the researchers used the Meaningful and Psychologically Rewarding Occupation Rating Scale, a validated instrument in which participants rate how well descriptors such as fun, boring, physically stimulating, mentally stimulating, connecting, and isolating apply to each activity on a scale from one to seven. A calculation method converts these ratings into scores for meaningfulness and psychological reward, each ranging from six to 42, with higher numbers indicating greater meaning or reward. The results were striking: every activity category scored above 30, and the two factors showed a strong positive correlation of 0.92, meaning that activities participants found meaningful were almost invariably the ones they found psychologically rewarding. Adventure activities, outdoor gardening, and outdoor play ranked highest, while foraging and indoor gardening, though still rated positively, came in lower.

The qualitative half of the study, based on a focus group interview with six of the eleven participants supported by photographs, videos, and field notes, explained why. Participants described outdoor play as something they had never considered or dared to do alone, with one remarking that it had not occurred to them to go sledging since childhood. The laughter and joy kept people going despite exhaustion, and for some the physical challenge stirred both sadness over their limitations and a sincere desire to improve. Others initially dismissed play as purposeless, only to conclude that perhaps doing something purely fun was exactly what they needed. Foraging, by contrast, produced a state of absorption and mindfulness, as participants learned to see what had been invisible to them, suddenly noticing cones or moss everywhere once they knew where to look.

The adventure activities generated the most dramatic emotional accounts. None of the participants had ever kayaked before, and one capsized after only fifteen to twenty minutes at sea, later describing the experience as passing through all the emotional realms: the excitement of trying the kayak, an indescribable feeling of freedom alone on the still sea, fear at falling into the water, relief at being rescued by the guide, and pleasure at having achieved it all. On the hike, one participant said he had overcome an invisible hurdle and now knew he could hike in the mountains again by himself. Outdoor gardening gave participants the satisfaction of real tasks that mattered and visible results, while indoor gardening offered the best opportunities for social connection and, for several, sparked a lasting interest in growing plants at home, with one participant reporting that she grew basil on her kitchen windowsill the following summer.

The authors interpret the findings through the lens of occupational science and the theory of occupational values, which distinguishes concrete value tied to results, symbolic value tied to personal and cultural meaning, and self-rewarding value found in the pleasure of performing an activity itself. The three highest-rated categories all took place entirely outdoors in natural settings, which the researchers believe acted as a supportive factor throughout the rehabilitation process, consistent with earlier findings that natural environments support clients across all phases of recovery. Equally important was the absence of performance pressure: participants could stop when they had had enough, and the outdoors even allowed them to step back from the group and work independently. The lower ratings for foraging and indoor gardening may reflect their result-oriented structure, since foraging sessions typically ended with a harvest or product, and indoor activities required cleanup and lacked fresh air, daylight, and the sense of freedom outside walls.

The study’s conclusion is that engagement in enjoyable, flexible, nature-based outdoor occupations supports psychological recovery and well-being in vocational rehabilitation settings, and that personally meaningful, low-pressure nature-assisted occupations deserve a permanent place in such programs. The findings also point to long-term effects: many participants continued nature-based activities on their own after the program ended, echoing earlier research showing that people find ways to incorporate nature into their lives and keep doing so after rehabilitation concludes. The authors caution that this was a feasibility study with a small sample, no specific target group, and a possible selection bias toward people already interested in nature, so the results reflect participants’ experiences of the activities rather than measured health outcomes. Even so, the work provides a concrete foundation for building nature-assisted rehabilitation programs in Iceland and for future studies targeting the needs of different user groups in vocational rehabilitation, suggesting that sometimes the most therapeutic prescription is permission to play, explore, and grow in the open air.

Subject of Research: Participants' experiences of meaningful and psychologically rewarding nature-assisted occupations within vocational rehabilitation in Iceland

Article Title: Meaningful and psychologically rewarding nature-assisted occupations – A feasibility study for improving alternatives in vocational rehabilitation in Iceland

Article References: Kristjánsdóttir, H. L., Siguröardóttir, S., & Pálsdóttir, A. M. (2025). Meaningful and psychologically rewarding nature-assisted occupations – A feasibility study for improving alternatives in vocational rehabilitation in Iceland. Scandinavian Journal of Occupational Therapy, 32(1), 1-14. https://doi.org/10.1080/11038128.2026.2633053

Image Credits: AI Generated

DOI: 10.1080/11038128.2026.2633053

Keywords: nature-assisted activities, vocational rehabilitation, occupational therapy, nature-based interventions, mental health, well-being, Iceland, adventure activities, gardening, stress recovery, meaningful occupation, feasibility study

The study, spearheaded by Saeedy Robat and colleagues, represents an unprecedented endeavor to synthesize extant evidence by evaluating 116 systematic reviews in the overview, and distilling them further through a second-order meta-analysis of 30 reviews selected for methodological rigor. These reviews collectively encompass an astonishing 3,870 primary studies, reflecting data from over ten million estimated participants — an unparalleled scale that endows the conclusions with remarkable statistical power and generalizability. Notably, the scope of evaluation spans both psychological and physiological dimensions of health, thereby recognizing the complex interplay between mind and body in the context of stress, anxiety, and depression.

Central to the study is the observation that nature-based interventions demonstrably reduce overall negative outcomes related to these mental health disorders when compared with control groups. The standardized mean difference (SMD) for overall negative outcomes was found to be -0.69, with a 95% confidence interval (CI) ranging from -1.05 to -0.33, which signals a moderate to strong effect size. Parsing these results further reveals that NBIs significantly diminish symptoms of anxiety, with an SMD of -0.83, as well as depressive symptoms, which show an SMD of -0.72. Physiological markers such as heart rate also exhibited improvements, marked by an SMD of -0.70. The reduction in negative affect further corroborates the therapeutic potential of engagement with nature, which was quantified with an SMD of -0.61.

Crucially, the study not only highlights reductions in negative symptomatology but also underscores the ability of NBIs to foster positive psychological states. The positive outcomes across interventions were even more pronounced, with an overall SMD of 0.90. Within this domain, increases in positive affect (SMD 0.52) and relaxation (SMD 2.85) stand out as particularly compelling evidence of nature’s restorative properties. These findings are significant because they suggest that NBIs do more than simply reduce distress—they actively promote enhanced well-being. By elevating positive affective experiences and inducing pronounced states of relaxation, NBIs appear to facilitate pathways to resilience and improved mental health recovery.

Delineating psychological versus physiological positive outcomes was another noteworthy element of this meta-analysis. The psychological dimensions of well-being featured a large effect size (SMD 1.18), signifying robust improvements in mental states such as mood and perceived relaxation. On the other hand, physiological outcomes exhibited a more modest and statistically nonsignificant improvement (SMD 0.24). This dichotomy suggests that while the psychological benefits of exposure to natural settings are profound and consistent, physiological changes might be influenced by additional variables or require longer durations for measurable impact. This nuanced insight calls for deeper explorations into the mechanisms through which NBIs exert their effects and the temporal dynamics involved.

Despite these encouraging findings, the study authors sound a note of caution about limitations inherent in the primary research landscape. A large proportion of the reviewed studies utilized passive control groups, such as waitlists or no-treatment comparators, rather than active controls engaging participants in alternative interventions. This raises the possibility that some effects might partially reflect placebo or expectancy biases rather than specific properties of nature exposure. Moreover, the inconsistent definitions and operationalizations of what constitutes an NBI across studies complicate the synthesis of results and cloud interpretations regarding which types of interventions are most effective. These methodological shortcomings underscore an urgent need to standardize intervention protocols and deploy active comparator groups in future trials to rigorously assess relative efficacy.

Another salient aspect of this meta-analytic work is the stringent quality assessment implemented through AMSTAR 2, a validated tool for appraising systematic review quality. Such a layered approach to evaluation enhances confidence in the robustness of the conclusions, separating high-quality evidence from lower-quality or potentially biased research. This is essential in a field that is rapidly expanding yet remains vulnerable to publication bias and variable study rigor. Addressing publication bias was another methodological forte of this study, reinforcing that the observed positive effects are unlikely to be artifacts of selective reporting.

From a clinical and public health perspective, these findings herald important implications. NBIs could represent a scalable, low-cost, and accessible complement to traditional pharmacological and psychotherapeutic treatments, particularly relevant in nonclinical populations or as preventive strategies. The magnitude of effect sizes observed—especially for anxiety, depression, and positive affective states—rivals or even surpasses those reported for some established interventions, bolstering the case for integrating natural settings into mental health promotion frameworks.

Furthermore, the physiological benefits, albeit modest, open intriguing possibilities for holistic health interventions that simultaneously engage both body and mind. The observed heart rate reductions align with theories of autonomic nervous system regulation facilitated by nature exposure, suggesting pathways through which psychological distress might be alleviated via somatic mechanisms. Future research utilizing biomarkers and neuroimaging tools could richly deepen understanding of these biopsychological processes.

Importantly, the study acknowledges that NBIs are not one-size-fits-all solutions. Variation in intervention type, intensity, duration, and participant characteristics likely moderates outcomes and warrants personalized approaches. For example, passive viewing of natural scenes might differ in effect from active engagement in gardening or forest bathing, yet current evidence synthesis struggles to disaggregate these nuances. This points toward a future research agenda emphasizing mechanistic studies, intervention standardization, and the identification of moderators and mediators.

In summary, this comprehensive systematic overview and second-order meta-analysis crystallizes a compelling narrative: nature-based interventions hold substantial promise as both preventive and therapeutic tools against the escalating burdens of stress, anxiety, and depression. The convergent evidence gathered from millions of individuals worldwide affirms the salutary power of nature not only to diminish negative emotions and physiological arousal but also to foster profoundly positive psychological states and relaxation. However, real-world translation hinges on bolstering the evidence base through high-quality trials with rigorous controls and standardized methodologies.

As mental health systems grapple with increasing demand and resource constraints, NBIs emerge as an attractive adjunctive strategy grounded in evolutionary affinity with natural environments. These findings revitalise the call for urban planners, healthcare providers, and policymakers to rethink and reintegrate nature access as a fundamental component of public health infrastructure. Further interdisciplinary collaborations involving psychology, environmental science, and clinical medicine will be essential to realizing the full potential of nature for nurturing mental health resilience in an increasingly urbanized and technology-driven world.

Ultimately, this landmark synthesis not only consolidates prior fragmented research but amplifies an urgent message: embedded in nature lies a powerful remedy against the pervasive mental health crises of our time. Leveraging this potential mandates a concerted scientific commitment to refining, standardizing, and scaling nature-based interventions so that their benefits can be reliably harnessed, equitably distributed, and enduringly sustained.

Subject of Research: Nature-based interventions for stress, anxiety, and depression

Article Title: A systematic overview and second-order meta-analysis of nature-based interventions for stress, anxiety and depression

Article References:
Saeedy Robat, E., Bayazi, M.H., Nayyeri, M. et al. A systematic overview and second-order meta-analysis of nature-based interventions for stress, anxiety and depression. Nat Hum Behav (2026). https://doi.org/10.1038/s41562-026-02433-4

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41562-026-02433-4