Outdoor swimming as a nature-based intervention for depression

Outdoor swimming as a nature-based intervention for depression: a feasibility randomised control trial

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN90851983

Enrollment

Registered

2022-05-19

Start date

2022-05-20

Completion date

Unknown

Last updated

2026-01-05

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Depression Mental and Behavioural Disorders

Interventions

The randomisation procedure will be set up and tested by the trial statistician using https://www.sealedenvelope.com™ with 1:1 allocation to either the intervention or control group with stratificatio

Eligibility

Sex/Gender

All

Age

18 Years to 99 Years

Inclusion criteria

Inclusion criteria: 1. Participants give fully informed consent to participate 2. Mild and moderate severity depression, as determined by the PHQ-9 (scores 5 -19) 3. Self-reported ability to swim a minimum distance: 3.1. For sea (50 m, 2 lengths of a normal swimming pool) 3.2. Lake (25 m, 1 length of a normal swimming pool) locations 3.3. No swimming experience required for outdoor unheated swimming pool (lido) 4. Adults aged 18 years or older

Exclusion criteria

Exclusion criteria: 1. People wishing to participate in a sea location who are not able to swim 50 m (2 lengths) in an indoor or fully heated outdoor pool 2. People wishing to participate in a lake location who are not able to swim 25 m (1 length) in an indoor or fully heated outdoor pool 3. Currently under the care of a secondary mental health NHS service 4. Risk of suicide or recent suicidal intent or attempts or self-harm requiring medical treatment 5. Other mental health problems to a severe degree 6. History of cardiac abnormalities (e.g., ischaemic heart disease/angina and congestive heart failure) 7. Immediate (first degree) relative history of cardiac events (GP consultation will be required for inclusion) 8. Respiratory conditions triggered by cold 9. Coldwater urticaria (a skin reaction to cold that appears within minutes after cold exposure) 10. Non-freezing cold injuries/Raynaud’s 11. Not able to speak English to a level that would enable them to understand safety instructions

Design outcomes

Primary

Measure	Time frame
1 Recruitment is measured by the number of eligible people consenting to participate in the study by October 2022 2. Retention of participants is measured by the number remaining engaged in the study activities for the duration of the study	—

Secondary

Measure	Time frame
1. Feasibility measures: 1.1. Swimming course attendance (intervention arm only) will be measured by totaling the number of sessions each person attends at the end of the study 1.2. Completion of questionnaires (in both arms) will be measured by totaling the number of questionnaires completed at baseline, post-intervention or at the equivalent timepoint for the usual care control group and in follow-up 1.3. Serious Adverse Events (SAEs) and adverse events will be recorded as they arise during the study 1.4. Completeness of data collected in both arms, at each timepoint. This will be measured by the number of questions completed by participants at baseline, or at the equivalent timepoint for the usual care control group and in follow-up. 2. Participant-reported outcomes: Each measure will be recorded at baseline, post-intervention or at the same timepoint in the usual care control and at follow up: 2.1. Depression symptom severity is measured by the Patient Health Questionnaire-9 (PHQ-9) 2.2. Anxiety symptom severity is measured by the General Anxiety Disorder-7 (GAD-7) 2.3. Wellbeing is measured using the Short form of the Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS) 2.4. Connectedness to nature is measured using the connectedness to nature scale 2.5. Loneliness is measured using the loneliness scale 2.6. Self-compassion is measured using the Sussex-Oxford Compassion for Self-Scale (SOCS-S) 2.7. Mindfulness is measured using the Five-Facet Mindfulness Questionnaire (FFMQ-15) 3. Health economic outcomes measures to assess health-related quality of life and medical resource use; each measure will be recorded at baseline, post-intervention or at the same timepoint in the usual care control and at follow up: 3.1. Health-related quality of life is measured using the EQ-5D-5L 3.2. Recovering quality of life is measured by using the ReQoL-10 3.3. The type and intensity of usual care, use of other health and social care services, such as GP visits, inpatient/outpati	—

Measure

Time frame

1. Feasibility measures: 1.1. Swimming course attendance (intervention arm only) will be measured by totaling the number of sessions each person attends at the end of the study 1.2. Completion of questionnaires (in both arms) will be measured by totaling the number of questionnaires completed at baseline, post-intervention or at the equivalent timepoint for the usual care control group and in follow-up 1.3. Serious Adverse Events (SAEs) and adverse events will be recorded as they arise during the study 1.4. Completeness of data collected in both arms, at each timepoint. This will be measured by the number of questions completed by participants at baseline, or at the equivalent timepoint for the usual care control group and in follow-up. 2. Participant-reported outcomes: Each measure will be recorded at baseline, post-intervention or at the same timepoint in the usual care control and at follow up: 2.1. Depression symptom severity is measured by the Patient Health Questionnaire-9 (PHQ-9) 2.2. Anxiety symptom severity is measured by the General Anxiety Disorder-7 (GAD-7) 2.3. Wellbeing is measured using the Short form of the Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS) 2.4. Connectedness to nature is measured using the connectedness to nature scale 2.5. Loneliness is measured using the loneliness scale 2.6. Self-compassion is measured using the Sussex-Oxford Compassion for Self-Scale (SOCS-S) 2.7. Mindfulness is measured using the Five-Facet Mindfulness Questionnaire (FFMQ-15) 3. Health economic outcomes measures to assess health-related quality of life and medical resource use; each measure will be recorded at baseline, post-intervention or at the same timepoint in the usual care control and at follow up: 3.1. Health-related quality of life is measured using the EQ-5D-5L 3.2. Recovering quality of life is measured by using the ReQoL-10 3.3. The type and intensity of usual care, use of other health and social care services, such as GP visits, inpatient/outpati

—

Countries

England, United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026