Green spaces exposure and the risk of common psychiatric disorders: A meta-analysis

Yimin Zhang; Tongyan Wu; Hao Yu; Jianfei Fu; Jin Xu; Liya Liu; Chunlan Tang; Zhen Li

doi:10.1016/j.ssmph.2024.101630

Green spaces exposure and the risk of common psychiatric disorders: A meta-analysis

SSM Popul Health. 2024 Feb 15:25:101630. doi: 10.1016/j.ssmph.2024.101630. eCollection 2024 Mar.

Authors

Yimin Zhang¹, Tongyan Wu¹, Hao Yu^{2

3}, Jianfei Fu⁴, Jin Xu¹, Liya Liu¹, Chunlan Tang¹, Zhen Li¹

Affiliations

¹ School of Public Health, Health Science Center, Ningbo University, Ningbo, China.
² Department of Urology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China.
³ Department of Urology, The Second Clinical Medical College of Nanjing Medical University, Nanjing, China.
⁴ Department of Medical Records and Statistics, Ningbo First Hospital, Ningbo, China.

Abstract

Objective: To explore the effects of green spaces exposure on common psychiatric disorders.

Methods: PubMed, Embase, Web of Science and MEDLINE were screened and articles published prior to November 15, 2023 were included. Analyses were performed on common psychiatric disorders, categorized into depression, anxiety, dementia, schizophrenia, and attention deficit hyperactivity disorder (ADHD). And the subgroup analyses were conducted for depression, anxiety, dementia, and schizophrenia.

Results: In total, 2,0064 studies were retrieved, 59 of which were included in our study; 37 for depression, 14 for anxiety, 8 for dementia, 7 for schizophrenia and 5 for ADHD. Green spaces were found to benefit the moderation of psychiatric disorders (OR = 0.91, 95% CI: 0.89 to 0.92). Green spaces positively influence depression (OR = 0.89, 95% CI: 0.86 to 0.93), regardless of the cross-sectional or cohort studies. Green spaces can also help mitigate the risk of anxiety (OR = 0.94, 95%CI:0.92 to 0.96). As an important index for measuring green spaces, a higher normalized difference vegetation index (NDVI) level related to a lower level of depression (OR = 0.95, 95%CI:0.91 to 0.98) and anxiety (OR = 0.95, 95%:0.92 to 0.98). The protection was also found in dementia (OR = 0.95, 95% CI: 0.93 to 0.96), schizophrenia (OR = 0.74, 95% CI: 0.67 to 0.82), and ADHD (OR = 0.89, 95% CI: 0.86 to 0.92) results.

Conclusion: Green spaces decrease the risk of psychiatric disorders, including depression, anxiety, dementia, schizophrenia, and ADHD. Further studies on green spaces and psychiatric disorders are needed, and more green spaces should be considered in city planning.

Keywords: Common psychiatric disorders; Green spaces; Mechanism; NDVI.