Sea Swimming as a Novel Intervention for Depression and Anxiety - a Feasibility Study Exploring Engagement and Effectiveness

Abstract

Background: Outdoor swimming is becoming increasingly popular, with enthusiasts claiming benefits to mental health. However, there is limited research into whether it could be effective as an intervention for people with anxiety and/or depression. Methods: 61 participants were recruited through GP surgeries, social prescribers and social media to an eight-session sea-swimming course and attendance rates were recorded. Self-administered questionnaires (Patient Health Questionnaire-9, Generalised Anxiety Disorder Assessment-7 and Work and Social Adjustment Scale) were completed at baseline, post-course and at three month follow-up. A point-of-care C-reactive protein device was used pre- and post-course to measure levels of inflammation. Findings: Overall attendance was 90·1% (382 sessions out of a possible 424). There were significant reductions (p<0·01) in the mean severity scores in depression pre- (mean ± SD, 13·0 ± 6·24) compared to post-course (5·1 ± 4·95) and anxiety pre- (2·2 ± 4·65) to post-course (5·0 ± 4·03). The recovery rates were high both immediately post-course (80·6 % for depression and 70·5% for anxiety) and at three month follow up. The qualitative data brought greater insight into the psychological benefits; a sense community, overcoming challenges and appreciating the moment were significant factors in improving mood, increasing confidence and motivating participants to swim. Interpretation: This study provides preliminary support for the engagement and effectiveness of sea swimming as a novel intervention for depression and anxiety. While not conclusive, the findings do not appear to be due to chance. A larger scale randomised control trial that can better examine the therapeutic potential of this intervention is warranted. Funding: Active Devon and Devon Partnership NHS Trust for the Devon Recovery Learning Community (DRLC) Declaration of Interests: Since the study, AB and CMH have had involvement with the Chill Therapy CIC in a voluntary and unpaid capacity. There are no other conflicts of interests. Ethics Approval Statement: Ethical approval was sought from the Health Research Authority (HRA) and the London-City & East Research Ethics Committee (REC) (REC reference: 20/LO/0725 IRAS project ID: 277692). All participants provided written informed consent. Trial Registration: clinicaltrials.gov (NCT04528485).