The influence of natural disasters and multiple natural disasters on self-harm and suicidal behaviour: findings from a nationally representative cohort study of Australian adolescents.

Few studies have examined the relationship between exposure to natural hazards and suicide and self-harm in youth. We extend prior research by investigating the association between multiple disasters and the risks of self-harm and suicide longitudinally in a nationally representative longitudinal cohort of adolescents 14 to 15 years to 18-19 years of age. Natural disasters were identified through parental self-reports for the local area. Different types of multiple disaster exposures were investigated including compound disasters (two or more disasters occurring in the last 12 months), cascading disasters (a disaster that leads to another disaster in the subsequent wave) and consecutive disasters (multiple disasters within the last two years or over an eight-year period). Using 8,714 person-waves of data from 2,908 adolescents, findings from random effect models suggest that parental reports of fire or floods increase the risk of self-harm ideation, self-harm, and suicidal ideation. Compound disasters of fire/flood and drought were also associated with increased risk of suicidal thoughts. Cascading disasters of drought followed by fire/flood increased the risks of self-harm but recurrent consecutive droughts were associated with lower risks of suicidal ideation. Australian adolescents are exposed to high rates of natural disasters that increase the risk of self-harm and thoughts of self-harm and suicide. Climate change will increase risk of natural disaster exposure for all countries. Despite these increased risks, there was resilience to disaster exposure particularly in the case of recurrent drought suggesting that youth, families and communities may well develop protective strategies to support mental health.