A systematic review of the anxiety-alleviation benefits of exposure to the natural environment

Abstract

Research suggests that exposure to natural environments can be beneficial for health, such as reducing physical illness and improving mood and cognitive ability. The potential benefits of nature have come into focus at a time when mental health issues are growing globally. Here, we have selected 24 studies from four databases for meta-analysis to explore the effects of exposure to the natural environment on the anxiety of the human body and summarize the influencing factors on the anxiety relief effect. A random-effect meta-analysis of anxiety state changes before and after exposure to natural environment shows that natural exposure effectively alleviated human anxiety (SMD −1.28, 95% CI: −1.65 to −0.92). The overall quality of the included papers, assessed using the PEDro scale, is considered to vary considerably, but most of the papers are rated between 4 and 7 which is considered fair or good. In addition, we have also investigated the potential moderators of anxiety-relieving effects of the nature. Our results shows that the age and exposure time of the subjects are related to the effect of anxiety relief. The results of the subgroup analysis of moderators prove that compared with the middle-aged people (SMD −0.63, 95% CI: −1.13 to −0.12), young people (SMD −1.50, 95% CI: −1.90 to −1.10) get better anxiety alleviation effect in the natural environment. In terms of exposure time, compared with 0.5–2 h (SMD −0.18, 95% CI: −0.59 to −0.23) and >2 h (SMD −0.84, 95% CI: −1.40 to −0.27) exposure periods, subjects get the maximum anxiety relief benefit when they spent <0.5 h (SMD −1.60, 95% CI: −1.93 to −1.27) in the natural environment. However, the quality of the included studies varies greatly and there is a significant heterogeneity in the meta-analysis. Study location, natural environment type and other moderator factors have no obvious correlation with anxiety-alleviation effect of the nature. A higher quality and more comprehensive study needs to be carried out to find out more moderators about the effects of the natural environment on anxiety alleviation. Further experimental studies should also be conducted to determine the mechanism by which natural exposure reduces anxiety so as to provide strong support for the construction and improvement of healthy natural environment.

Effects of immersion in a simulated natural environment on stress reduction and emotional arousal: A systematic review and meta-analysis

“…Although fewer studies were included in the meta-analysis of each relatively specific emotional response, the results still confirm the effectiveness of the simulated nature in improving emotional states. Actual natural environments have been proven to help individuals escape from depression ( Roberts et al, 2019 ; Wang et al, 2019 ) and anxiety ( Zhang et al, 2022 ). If more evidence demonstrates that these effects are also present in simulated nature, it could serve as a “green narrow-spectrum antibiotic” for treating specific psychological disorders and as a preventive measure for mentally sub-healthy people.…”

“…Actual natural environments have been proven to help individuals escape from depression (Roberts et al, 2019;Wang FIGURE 4 Subgroup analysis of the effects of simulated nature exposure on fatigue. (Zhang et al, 2022). If more evidence demonstrates that these effects are also present in simulated nature, it could serve as a "green narrow-spectrum antibiotic" for treating specific psychological disorders and as a preventive measure for mentally sub-healthy people.…”

Greenspaces And Cardiovascular Health

“…Overall, a majority of cross-sectional and longitudinal evidence suggests that greenspace exposure is associated with a lower incidence of depressive symptoms, 144 although anxiety alleviation by greenspaces varies with participant age and exposure time. 145 A more recent meta-analysis examining anxiety and depression outcomes related to exposure to greenness did not find significant outcomes related to anxiety. 146 In addition to the quantitative findings, 8 studies in the systematic review included subjective evaluations.…”

Impact of tourists’ environmental preferences and place attachment on their perceived health benefits at Langya Mountain

“…地点情感关系的重要依据 [14] 。人们在长时间接触某 个特定场所后， 产生了深厚的情感、 偏好和行为， 这 种人与场所间的归属与联结关系就是场所依恋 [15,16] 。 Williams 等 [17] 提出场所依恋二维结构包含场所依赖 (Place Dependence)和场所认同(Place Identity)， 并 基于此开发了场所依恋评测量表， 该量表是目前国 内外相关研究中使用最为频繁的测量方法。场所 依赖是个体对场所功能上的依赖， 如对场所中环境 景观、 公共资源、 服务设施的实质性需求； 场所认同 建立在个体对场地感知、 记忆、 印象的基础上， 表现 为个体对于场所的情感依恋 [18] 。场所依恋会使个体 将地方看作自我的一个部分， 身处该地能给个体带 来安全感， 提升自我认同， 增加正面情绪 [19] 。 环境偏好和场所依恋都是个体与环境间的互 动关系， 环境偏好作为一种积极的心理机制， 是场 所依恋关系建立的条件之一。人们本能地对开放、 舒适、 安全的环境产生需求及偏好， 进而引发依恋 关系。国内外相关研究结果也证实了环境偏好对 场所依恋的积极影响。如 Kastenholz 等 [20] 针对葡萄 牙 3 个内陆村庄的游客展开的研究发现， 游客的环 境偏好与场所依恋正相关； Moore 等 [21] 以铁路文化 公园为研究对象， 发现场所认同作为场所依赖的中 介因素影响游客对公园的评价与态度； 刘群阅等 [22] 以福州的 9 个城市公园为例， 探讨环境偏好与场所 依恋在城市公园恢复性评价模型中的作用， 结果表 表 1 环境偏好量表 [25] 。此外， 自然 环境能够帮助人们减少心理压力、 舒缓情绪、 消除 疲劳 [26] 。人们在自然环境中获得的健康效益主要表 现为 3 个层面： 缓解心理压力、 减少身体疾病、 产生 长期积极的社会效应 [5] 。健康效益感知量表能快速 有效测量游客在景观环境中感受到的健康效益 [27] ， 如 Peschardt 等 [28] 在研究中采用该量表发现， 游客对 户外自然景观的满意度越高， 越能在其中缓解压力 与疲惫； 曾真等 [29] 以福建三明绿道为例， 也验证了这 一观点， 即游憩体验越满意的游客对环境提供的舒 适感越依恋， 从而越快地恢复身心健康。游客在基 本需求得到满足的情况下， 依恋感更容易生成， 进 而促进个体生理及心理上的放松 [30] 。Lehto 等 [31] 性展开测量， 相关系数的显著程度越高， 则量表的 内容效度越高 [33] 。表 2 显示， 各测量变量与所在潜 在变量的相关系数在 0.659~0.901 之间， 说明量表具 有较好的内容效度。收敛效度代表数据内部的一 致性、 稳定性和聚集性， 可以通过标准化因子负荷、 [35] 与朱正英等 [36] 的 表 3 修正后的环境偏好模型信效度分析结果 [27] ； 吴天杰 等 [10]…”