The association between green space around schools, screen time for entertainment, and adolescent depressive symptoms: A nationwide study from China

学校周围的绿色空间、娱乐屏幕时间与青少年抑郁症状之间的关联：一项来自中国的全国性研究

Authors: Yu Liu , Shuqin Li , Tongyan Deng , Lanlan Li , Runyu Wei , Ying Zhang , Jinping Ou , Fangbiao Tao , Yuhui Wan.

Source: Environ Res. .2024 Oct 5;263(Pt 2):120100.

doi: 10.1016/j.envres.2024.120100. 

Abstract

Background: Natural green environments are beneficial to people's mental health, while too much screen time may be harmful to adolescents' mental health. However, it is not clear how green spaces and screen time affect mental health together in adolescents.

Methods: A total of 22,868 adolescents were recruited from October to December 2021 in eight cities in China, through multistage cluster sampling. The Patient Health Questionnaire (PHQ-9) was used to investigate adolescents' depressive symptoms, and the Normalised Vegetation Index for the 200m, 500m and 1000m buffer zones around the school represents the green cover around the school. We used binary logistic regression to analyse the association between green space, screen time and depressive symptoms.

Results: In fully adjusted models, the highest quartile of NDVI in the 200m, 500m and 1000m buffer zones around the school was a protective factor for depressive symptoms. For less than 2 h of recreational screen time, the highest quartiles of the NDVI and the association with depressive symptoms were negatively correlated for the 200m, 500m and 1000m buffer zones (NDVI200: 0.904(0.848-0.964)), NDVI500: 0.863(0.808-0.921), NDVI1000: 0.862(0.808-0.920)). The highest quartiles of NDVI in all buffers were not associated with depressive symptoms when the screen time was >2 h. The association between green space and depressive symptoms at lower recreational screen time was observed to be stronger in the group of adolescents with a lower family economic status (NDVI200: 0.780(0.695-0.876), NDVI500: 0.838(0.748-0.938), NDVI1000: 0.783(0.698-0.879)). No potential gender differences were observed.

Conclusions: For adolescents with less than 2 h of recreational screen time per day, the greenery around the school had a protective effect on their mental health, especially for adolescents from economically disadvantaged families. Green spaces around schools are significant in improving health inequities.

Keywords: Adolescents; Depressive symptoms; Green space; Screen time.

摘要

背景：自然的绿色环境有益于人们的心理健康，而过多的屏幕时间可能对青少年的心理健康有害。然而，目前尚不清楚绿色空间和屏幕时间如何共同影响青少年的心理健康。

方法：2021年10月至12月在中国8个城市共招募22,868名青少年，通过多阶段整群抽样。患者健康问卷（PHQ-9）用于调查青少年的抑郁症状，学校周围 200m、500m和1000m缓冲区的标准化植被指数代表学校周围的绿色覆盖。我们使用二元logistic回归来分析绿色空间、屏幕时间和抑郁症状之间的关联。

结果： 在完全调整的模型中，学校周围200m、500m和1000m缓冲区NDVI的最高四分位数是抑郁症状的保护因素。在不到2 h的娱乐屏幕时间里，NDVI的最高四分位数和与200m、500m和1000m缓冲区的相关性呈负相关（NDVI200： 0.904（0.848-0.964））， NDVI500：0.863（0.808-0.921），NDVI1000: 0.862(0.808-0.920))。当屏幕时间为＞2 h 时，所有缓冲区中NDVI的最高四分位数与抑郁症状无关。在家庭经济状况较低的青少年群体中，观察到绿色空间与较低娱乐屏幕时间的抑郁症状之间的关联更强（NDVI200： 0.780（0.695-0.876）， NDVI500：0.838（0.748-0.938），NDVI1000: 0.783(0.698-0.879))。未观察到潜在的性别差异。

结论：对于每天娱乐屏幕时间少于2 h的青少年，学校周围的绿化对他们的心理健康有保护作用，尤其是对于来自经济弱势家庭的青少年。学校周围的绿色空间对于改善健康不平等具有重要意义。