Genome-wide tandem repeat expansions modify schizophrenia risk in the presence of a 22q11.2 deletion.

Around one-tenth of U.S. adults aged 45 and above report a decline in memory or cognitive function (). Such loss of episodic memory or cognitive decline can progress to Alzheimer’s disease, negatively impacting independence, decision-making, and overall well-being (; ). Exposure to natural environments has emerged as a key strategy to support brain health and cognitive functioning (; ). Natural environments, such as greenspaces, offer unique experiences that foster active engagement, exploration, creativity, risk-taking, skill development, and a sense of mastery and personal control (; ; ). According to attention restoration theory, both spending time in and merely viewing natural environments can facilitate recovery from mental fatigue and stress, thereby enhancing concentration and focus (; ). Moreover, proximity to outdoor greenery has been shown to enrich microbial diversity in the indoor environment (), which may positively influence cognitive development (). Collectively, these benefits may arise directly from the intrinsic qualities of greenspaces or indirectly through pathways whereby natural environments affect other factors that support cognitive function. Numerous epidemiological studies have investigated the relationship between residential greenspaces and various cognitive health outcomes (e.g., ; ; ). Most report beneficial associations, such as slower cognitive decline in older adults (; ; ), and enhanced cognitive development during childhood (; ) and adolescence (). Exposure to residential greenness has been linked to reduced risks of neurodegenerative conditions (), and a lower likelihood of developing Alzheimer’s disease (). Nevertheless, findings are not entirely consistent. Some studies have reported no associations between greenspace and cognitive function (), while others reported null associations with park area () or even suggested that greater access to natural environments may be linked to a higher risk of dementia and cognitive impairment (). Overall, the previously investigated outcomes have primarily focused on clinically diagnosed Alzheimer’s disease or broader indicators of cognitive functioning, with relatively limited attention to memory performance specifically. In recent years, several studies examining greenspace and memory have begun to emerge, although findings remain mixed. In a large U.S. cohort, no associations were observed between residential greenspace and learning or working memory in middle-aged women (), while another study similarly reported no association between greenspace and short-term memory (). By contrast, a U.K. study reported that surrounding greenness was positively associated with short-term and overall memory performance in adults (). Importantly, most of these studies relied on overall or undifferentiated measures of greenness, which may mask meaningful heterogeneity in the cognitive relevance of different greenspace types. For example, an Australian longitudinal study found that greater tree canopy (versus open grass) was associated with higher odds of excellent self-rated memory, whereas open grass did not confer comparable benefits (). These findings suggest that specific vegetation characteristics, rather than overall greenness alone, may be more relevant for memory. Despite these advances, the epidemiologic evidence for associations between greenspace and memory remains scarce and inconsistent.