Associations of exposure to heatwaves with depression and anxiety among adolescents: A cross-sectional study of the Chinese adolescent health survey

Abstract

Background: Limited research has examined the relationship between heatwaves and adolescent mental health, particularly depression and anxiety. This study aimed to explore the relationship between heatwaves and depression and anxiety.

Methods: We conducted a cross-sectional study including 19,852 adolescents (mean age 15.16 years; 50.2 % females). Air temperature data were from the fifth generation European ReAnalysis-Land (ERA5-Land) dataset. Heat exposure was assessed using three heatwave metrics: The excess heat factor-based (HWM1), maximum temperature-based (HWM2), and minimum temperature-based (HWM3) heatwave magnitude indices. Depression and anxiety were assessed using the PHQ-9 and GAD-7 scales. Subgroup analyses evaluated interactions with sex, grade and region of school.

Results: Depression and anxiety prevalence were 19.37 % and 16.27 %, respectively. Heatwaves were associated with depression (OR [95 % CI]: 1.13 [1.09-1.17]) and anxiety (OR [95 % CI]: 1.12 [1.08-1.16]) based on HWM1. Significant associations existed for depression alone (OR [95 % CI]: 1.14 [1.09-1.20]), anxiety alone (OR [95 % CI]: 1.13 [1.06-1.21]), and comorbid depression and anxiety (OR [95 % CI]: 1.13 [1.09-1.18]). Associations using HWM2 and HWM3 showed consistent directions but varied significance. We observed significant interactions between heatwaves and sex for anxiety alone, and between heatwaves and region of school for both depression alone and comorbid depression-anxiety (all P for interaction <0.05).

Limitations: The cross-sectional design constrained our capacity to draw causal inferences.

Conclusions: Heatwaves were associated with a significant of prevalence depression, anxiety, and their comorbidity, with males and rural students potentially more susceptible to these effects.

Keywords: Adolescents; Anxiety; Depression; Heatwaves.