The effects of blue spaces on mental health and associated biomarkers

Green spaces have been shown to have many benefits for physical and mental health. Recently, blue spaces have been introduced as another field of research and have been suggested to have similar health effects. This scoping review summarized the current state of the knowledge on how blue space exposure (views and visits) affects mental health (depression, anxiety, stress, and associated biomarkers). A keyword search was developed for PubMed, Web of Science, Embase, and PsycINFO. Identified articles were then imported into Rayyan and put through a title review, an abstract review, and finally a full-text review. Five articles were found to have direct relevance to the study. Two articles showed that blue space visits had benefits to general mental health and possibly depression. Two studies investigated blue space views, one showing benefits for general mental health and the other showing benefits for depression. One study showed that both blue space views and visits had positive impacts on mental health and that blue space visits had a stronger effect than merely viewing blue spaces. However, no articles discussed mental health-associated biomarkers. These studies all provide evidence that blue space exposure has a positive impact on mental health, but based on the small number of articles there is not enough evidence to conclude measurable changes in biomarker responses. Further areas of research include man-made/urban blue spaces, other mental health outcomes, virtual reality, and their effects on biomarkers. HIGHLIGHTS Views of and visits to blue space improve mental health. Visiting blue space has greater mental health benefits than blue space views. Blue space results in lower depression symptoms.