Association between artificial light at night and the incidence of anxiety: a global ecological study

Abstract Background Although the effects of artificial light at night (ALAN) on human health are well-documented, its impact on the incidence of anxiety remains unclear. Method To evaluate the potential association between ALAN and the incidence of anxiety, this ecological study analysed the age-standardised anxiety incidence rate (ASAIR) for 174 countries and territories obtained from the Global Burden of Disease Study (2000–2019). The annual average ALAN intensity for each country was estimated using night-time satellite images. Initially, a Geographic Detector (GD) was employed to examine the spatial association between the ALAN intensity and the ASAIR. Thereafter, linear mixed-effects models (LMEMs) were applied to assess the impact of ALAN intensity on the incidence of anxiety. Results From 2000 to 2019, the global ASAIR for anxiety was 603.78 per 100,000 population, and the mean ALAN intensity was 4.95 digital numbers. The GD analysis revealed a statistically significant spatial association between ALAN intensity and the ASAIR over the study period. Moreover, results from LMEMs demonstrated that, after adjusting for potential confounders, ALAN intensity was significantly associated with an increased ASAIR, with an adjusted β coefficient of 2.29 (95% confidence interval: 1.48–2.92). Notably, ALAN-associated adverse effects appeared more pronounced among females and individuals aged 19 years or younger. The findings of the subgroup and sensitivity analyses were largely consistent with the primary results. Conclusion From a global perspective, ALAN may be associated with an increased incidence of anxiety. These findings have implications for urban planning and the development of public health policies targeting light pollution mitigation; nevertheless, further validation is necessary.