Title: Outdoor swimming as a nature-based social prescribing intervention for depression: a feasibility randomised control trial
Funder: Department of Health and Social Care

Abstract: Background Depression, characterised by persistent low mood and/or loss of pleasure, is common with a lifetime prevalence of 10.8% worldwide (1) which is increasing (2). Treatment routinely includes medication and talking therapies (3). Despite treatment, recovery from symptoms is modest (4,5). The evidence for outdoor swimming as an intervention to support recovery from symptoms of depression is growing (6,7), following anecdotal reports of reduced symptoms of depression (8,9). The effects seen may be due to increased connectedness with nature, self-confidence, peer-support, the challenge and the physiological impact of cold-water on the body (10). The number of social prescribing link workers in GP practices is increasing (11). Social prescribing link workers connect people, referred by medical professionals and voluntary organisations, to community groups and agencies that offer the most appropriate support for each person. Recent policies advocate patient choice to support effective treatment (12) including community- and nature-based activities (13). Aims To assess the feasibility of undertaking a definitive fully-powered RCT, comparing a socially-prescribed introductory outdoor swimming course, offered in addition to usual care, compared to a group receiving usual care only, in people who have mild to moderate depression. To determine recruitment and retention rates, acceptability of randomisation and measures used to inform the sample size calculation for a definitive fully-powered RCT. To understand the experience of study participants by using focus group discussions, questionnaires and interviews. Method Our aims will be achieved by: The feasibility RCT being conducted with 84 participants with mild to moderate symptoms of depression. Participants recruited through social prescribing pathways from three separate locations (London, Worcester and North Devon) will be randomised to either: Usual care for 8 weeks and followed up for a further 8 weeks. Treated in accordance with their medical provider, or Usual care (as above) plus attending an introductory Outdoor swimming course, for 1hr per week for 8 weeks, followed up 8 weeks later. Both groups will complete outcome measures (including PHQ-9, GAD-7) pre-randomisation, at the end of the course and 8 weeks later (follow up). Conducting an embedded qualitative component to: Explore what was experienced as helpful and unhelpful about the swimming interventions and outcome measures. This will inform the choice of outcome measures to be used in the definitive fully-powered RCT. Understand barriers that may reduce participation in a definitive fully-powered RCT. Participants, those who declined to participate but consent to a minimal data collection, the social prescribers themselves and outdoor swimming coaches/teachers will be consulted. Timelines Project milestones include: March 2022. Ethics approvals May 2022. Recruitment complete and allocation Start of June 2022. Start course Aug 2022. Course end Sept-Nov 2022. Final data collection and transcription Dec 2022. Data analysis End of Jan 2023. Final report and dissemination Anticipated impact The anticipated impacts are to: Develop the capability to deliver a definitive fully-powered RCT if feasibility is successful. Produce a short video and podcast to support interest in a definitive fully-powered RCT. Write up the feasibility study for peer-reviewed publication and relevant grey literature.

Lay abstract: Background Many people say outdoor swimming improves their mental health. There has been some research showing outdoor swimming helps people with depression, but not enough to say for certain. Social prescribing link workers work with GPs to support individuals to take greater control of their own health. They link patients with community-based activities and non-medical support e.g. gardening, volunteering opportunities or exercise and sports groups. In this study, we want social prescribing link workers to offer an outdoor swimming course to adults with depression to see if it can help them. Aim This study is a small study called a feasibility study. It will help us to decide if we can go on to run a larger clinical trial and, if so, how best to design it. The larger clinical trial would tell us if outdoor swimming does help improve depression. It will also give us information about who and how it might help. Design and Methods Social prescribing link workers will give information about this research study to people they think it might help. Individuals who decide to take part will either go on an 8-week outdoor swimming course, as well as their usual care, or have their usual care only. Usual care may include talking therapies and/or antidepressant medications and community activities. The usual care-only group will be offered the swimming course after the study finishes. The outdoor swimming courses will be run by experienced coaches and will build confidence and water safety skills. During the study, participants will fill out questionnaires that ask about their depression, mental health, wellbeing, and use of health care services. Participants will complete them before the study starts, immediately after the swimming course (or usual care) and 8 weeks later. We will also get feedback from participants, swimming coaches, social prescribing link workers as well as people who declined or dropped out of the study. Their feedback will help us design the full trial. Patient and Public involvement (PPI) We have had three PPI meetings to help us plan this study. They have included people with depression, from diverse backgrounds and people who have found swimming helpful. Two members of our research team are PPI co-applicants and we have 3 PPI members on an independent panel that help oversee the study. During the study we will also meet six times with a PPI group who will help us with planning how we should advertise the study, remove barriers to participation and communicate the findings to the public. Dissemination The results will be shared with participants and published in a science journal. A short film and podcast will also be made to spark interest in the larger trial.

Research activity codes: 6.7 PHYSICAL
Health categories: MENTAL HEALTH