“More research needed”

“More research is needed to understand the relationships between natural light and circadian rhythms, and their effects on health and well-being. Many societies are ageing, so the links between a lack of sunlight, dementia and Alzheimer’s disease should be explored. Another potential research question is whether there is any relation between daylight exposure and increased chronic inflammatory and autoimmune diseases. Impacts on the environment need to be better understood; there have been few studies on shadowing and vegetation in cities, for example, or on the development of moulds inside buildings, which might affect health.” (Zielinska-Dabkowska and Xavia, 2019)

“Although these studies need to be replicated, the rigid designs and large sample sizes provide some evidence for a relation between noise exposure and depression, though further studies are needed to establish biological pathways and causal relationship.” (van den Bosch et al. 2019)

“To provide knowledge for evidence-based decisions, any causal relation between natural environments and depression should be confirmed through longitudinal or experimental study designs, including analyses of biochemical reactions to nature exposure. Equally, contextualization and quantification of various nature types, including biodiversity, are necessary to analyze relative impact on depression.” (van den Bosch et al. 2019)