Exposure to outdoor blue spaces can help improve human health by reducing stress, promoting social relationships, and physical activity. While most studies have focused on the adverse health effects of scuba diving, very few have assessed its health benefits. Moreover, when scuba diving is done in large groups with no diving instructor or pre-dive briefing, negative environmental impacts are generated and negative impacts on human health may also occur due to overcrowding, which may create stress. This is the first study to evaluate the effects of scuba diving on divers' mental health using their diving practices to estimate the impacts on the ecosystem. In the marine-protected area of Cap de Creus and adjacent areas, we assessed the mental health of 176 divers and 70 beach users (control group) by employing a 29-item version of Profile of Mood State (POMS) questionnaires. According to the parameters associated with reduced environmental impacts, two scuba diving experiences were established. Poisson regression models were performed to assess both the contribution of the activity and diving experiences to POMS scores. Both groups (scuba divers and beach goers) reduced their POMS scores after carrying out the activities. Although no significant differences were found between beach and scuba diving activities, nor between the two different scuba diving experiences, our results showed that subjects with regular medication intake due to a chronic or psychiatric illness had a POMS reduction score significantly higher than other subjects. We conclude that both beach and scuba diving activities have positive effects for human mental health, particularly among subjects with regular medication intake.
Keywords: ecosystem health; medication; mental health; scuba diving.