Research by the Mental Health Foundation (2022) calculated that mental health problems cost the UK economy at least £117.9 billion per year, most of which (72%) is outside the healthcare sector and is due to the lost productivity of people living with mental health conditions, as well as costs incurred by unpaid informal carers. [Mental Health Foundation and London School of Economics and Political Science (2022) The economic case for investing in the prevention of mental health conditions in the UK Available at https://www.mentalhealth.org.uk/explore-mental-health/publications/economic-case-investing-prevention-mental-health-conditions-UK]
Given the vital role that STH has been shown to play in preventing mental ill health and helping people to live well with mental health conditions, as well as its physical health benefits, the economic benefits of STH services are clear.
The small number of studies that have estimated the economic value associated with nature-based interventions for mental health have typically shown them to be cost-effective and to result in savings to society. Whilst not all specifically STH studies, they do include STH or other formally led nature-based activities.
“There is now enough evidence to include gardening and nature in the health care agenda. The key point is that gardening, plants and horticultural activities are excellent tools for creating a healthier society where the costs of health care and human suffering can be substantially reduced. We could see at least a £5 health benefit for every £1 spent. Since about £60 billion is spent on long-term conditions, 80 per cent of which could be prevented by a healthier lifestyle, there is a significant incentive to develop a programme that includes horticulture.” Dr Matilda van den Bosch & Dr William Bird (MBE)
A study published in Pretty et al (2011) suggested that just a 1% shift in the sedentary UK population to a ‘healthy pathway’ could save 1,063 lives and £1.44 billion each year. [Pretty et al 2011, in Human Wellbeing, Chapter 23: Health Values from Ecosystems]
The national evaluation of the British Trust for Conservation Volunteers (BTCV) Green Gym project (Yerrell 2008) between 2005 and 2009 estimated that for every £1 invested in green gyms, £2.55 would be saved in treating illness related to physical inactivity.
The Wildlife Trusts recently examined the role that a thriving wildlife-rich environment can play in reducing demand on NHS services and claim that offering one of the nature-based programs to an estimated 1.2 million people could lead to yearly cost saving of £635.6m. [A Natural Health Service: Improving lives and saving money (Summary) and The Wildlife Trusts’ Natural Health Services: A rapid economic assessment of The Wildlife Trusts’ Natural Health Services (Full technical report) – The Wildlife Trusts, 2023]
In a report on Trust Links community horticulture (in Essex), the authors identify cost savings to three types of public services: health and social care, police and criminal justice, and education. The authors showed that the associated increase in happiness and life satisfaction from woodland therapy, therapeutic horticulture, ecotherapy/green care, and tai chi, predicted savings in public service use per person of £830–£31,520 (after 1 year) and £6,450– £11,980 (after 10 years). Saved costs considered include prescription costs, medical consultation costs, community psychiatric nurse costs, benefits payments, and Disability Living Allowance payment. The total benefits to costs for that project were £6.42 for Y1 and £7.61 for Y10. [Pretty and Barton 2020), Saving Public Health Costs Whilst Increasing Life Satisfaction and Happiness. International Journal of Environment Research and Public Health. 17(21) 7769 ]
The following four studies cited by Natural England in Links between natural environments and mental health: evidence briefing (EIN065) – Natural England, 2022 (Updated) all show positive return on investment.
A Social Return on Investment (SROI) study by The Wildlife Trust found that environments rich in wildlife may result in better mental health for people with low wellbeing at baseline. The SROI found a return of between £4.20 and £11.94 for every £1 invested. [Bagnall, A. M., & Brymer, E. (2019). Social return on investment analysis of the health and wellbeing impacts of Wildlife Trust programmes. Available at: https://www.wildlifetrusts.org/sites/default/files/2019-09/SROI%20Report%20FINAL%20-%20DIGITAL.pdf ]
- An evidence review commissioned by Natural England found that SROI analyses for nature-based initiatives for people with mental health issues ranged from £2.35 to £10.70 per £1 invested. [Bragg, R., & Leck, C. (2017). Good practice in social prescribing for mental health: The role of nature-based interventions. Natural England commissioned reports, 228. Available at: http://publications.naturalengland.org.uk/publication/5134438692814848 ]
- The ‘Ecominds’ programme run by the charity Mind, provided nature-based interventions to support mental health to 12,000 people across England. Projects included horticultural and agricultural schemes, walking groups and regeneration projects in local parks. Ecominds was estimated to have resulted in savings (through reduced NHS costs, benefits reductions, and increased tax contributions) of around £7,082 per participant. It was estimated the programme would result in savings of £1.46m for 246 people who had found full-time work following participation. [Vardakoulias, O. (2013). The economic benefits of ecominds: A case study approach. NEF Consulting. Available at: https://www.mind.org.uk/media-a/4424/theeconomic-benefits-of-ecominds-report.pdf ]
- The Scottish ‘Branching Out’ programme (where patients with mental health issues are prescribed a series of formally-led woodland activities) found that based for 335 service users per year, the cost per Quality Adjusted Life Year gained (QALY) was £8,600 in comparison to the NICE threshold of £20-30,000 per QALY. [Wilson, N., Fleming, S., Jones, R., Lafferty, K., Cathrine, K., Seaman, P., & Knifton, L. (2010). Green shoots of recovery: The impact of a mental health ecotherapy programme. Mental Health Review Journal. doi:10.5042/mhrj.2010.0366 ]