Extreme Cold Events and Adolescent Mental Health: Evidence from a National School-Based Survey in China.

Adolescent mental health issues are a growing public health concern, and extreme temperature events (ETEs) driven by climate change may exacerbate these challenges. However, the impact of cold spells, a common ETE, on adolescent mental health remains unclear. The study aims to explore the impacts of cold spells, defined with different intensities and durations, on adolescent mental health across China while also establishing risk-driven thresholds for cold spells and identifying vulnerable subpopulations. The data was derived from the 2019 survey cycle of the Chinese National Surveillance on Students' Constitution and Health, conducted between September and December and encompassing 149,697 adolescents aged 10-18 from 30 provinces. Cold spells were defined by using a series of cutoff temperature thresholds and durations. We assessed cold spell frequency and average cold intensity during the 12 months prior to the survey based on 0.1° × 0.1° gridded apparent temperature data. Troubled symptoms were measured using the Kessler Psychological Distress Scale and the Warwick-Edinburgh Mental Wellbeing Scale. We applied generalized linear mixed models to estimate the associations, and risk-driven thresholds for cold spells were determined based on the distribution of risk estimates. Among participants, 10.9% reported troubled symptoms. Higher cold spell frequency and average cold intensity were associated with increased odds of troubled symptoms. Risk-related thresholds were set using daily apparent temperatures at or below the fifth percentile for ≥3 days (P5_3d) or the 2.5 percentile for ≥2 days (P2.5_2d). Early warning and avoidance of cold spell exposure could potentially prevent 2.8-3.5% of troubled symptoms. Younger adolescents, female adolescents, rural residents, and those in lower GDP regions were more vulnerable. Our findings suggest that cold spells exceeding certain thresholds may adversely impact adolescent mental health, emphasizing the need for targeted cold-health early warning systems.