Outdoor swimming as a nature-based intervention for depression

INTERVENTION: 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 stratification by location and random permuted blocks. This is a feasibility RCT with 1:1 allocation to a swim course and usual care intervention or usual care group. The study includes a qualitative evaluation of participants’ experiences of the outdoor swimming intervention with a focus on better understanding barriers and facilitators to engaging in outdoor swimming. Eighty‐eight people meeting eligibility criteria for mild to moderate depression are randomly allocated to receive either their usual care along with eight 1‐hour sessions of an introductory outdoor swimming course or their usual care. Participants are asked to complete survey measures at baseline, post‐intervention or at the same point for the usual care control group and again in follow‐up, 8 weeks later. In addition, participants are invited to focus groups to discuss their experiences of the study. CONDITION: Depression ; Mental and Behavioural Disorders PRIMARY OUTCOME: ; 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; 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 SECONDARY OUTCOME: ; 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/outpatient care, A&E, medication use, travel time and cost to travel to and from all different treatments/appointments attendances, estimated using the Clinical Service Receipt Inventory; 3.4. Health‐related productivity losses measured using the IMTA Productivity Cost Questionnaire;