Longitudinal effects of bushfire harm on adolescent mental health

Background: In Australia, harms associated with bushfires are expected to increase as the severity and frequency of bushfires increase with climate change. Bushfire harm includes negative impacts on mental health, particularly for adolescents. Evidence suggests that elevated incidence of mental illness can persist long-term after bushfire harm. This study extends our team’s earlier cross-sectional analysis within the same cohort. It examines effects of the Black Summer bushfires (2019-2020) on adolescents’ mental health measured prospectively and explores risk and protective factors associated with sustained mental health problems following bushfire harm. Methods: A broadly representative sample of 2967 Australian adolescents was recruited in 2019-2022 at age 13-14 and followed for 24 months. Bushfire exposure and harm, and symptoms of depression, anxiety, psychological distress, insomnia, and suicidality were measured. Linear regression models examined the effects of bushfires over time; logistic regression identified predictors of these effects. Results: 167 (5.4%) participants reported bushfire harm. Bushfire harm was not a significant predictor of any mental health outcomes at 24 months. Baseline symptoms were most strongly associated with 24-month outcomes. Participants who were gender or sexuality diverse, reported adverse childhood experiences, or had a history of mental health problems had increased risk of symptoms of depression, anxiety, distress and insomnia at 24-month follow-up compared to those who did not have these risk factors. Conclusions: Bushfire-harmed adolescents did not show significantly elevated mental health symptoms compared to unexposed peers 24 months later. This finding is encouraging, though its underlying causes are unclear and require further research.