Climate-induced extreme heat associated with suicide risk mediated by poor sleep and emotional dysregulation: A nationally representative panel study from Bangladesh.

Abstract

Climate change-induced heat exposure is an emerging public health concern with potential mental health consequences, including suicide risk. Yet, in climate-vulnerable low- and middle-income countries the association between heat exposure and suicide risk, and the mediating mechanisms underlying this connection, remain underexplored. Using a nationally representative two-round panel survey from Bangladesh (n=7,492), we empirically examined whether poor sleep quality and emotional dysregulation mediate the relationship between exposure to extreme heat and suicide risk. Risk was assessed using a validated suicide cognitions scale across two seasonal rounds surveying the same individuals. Exposure to days ≥28°C over a two-week period was the lowest temperature threshold significantly associated with elevated suicide risk, with the highest risk detected at ≥35°C. At this 35°C threshold, 29.5% of the total association was mediated through poor sleep quality and 1.8% through emotional dysregulation. Risk was notably higher during the summer, and among less educated and poorer populations. This study provides novel evidence from a climate-vulnerable country on psychosocial mechanisms connecting heat and suicidality. As heat extremes intensify across the Global South, targeted mental health interventions, both infrastructural and psychological, may need consideration in climate adaptation strategies to protect the well-being of at-risk populations.