The Lethal Connection: Investigating the Relationship of Drought Conditions on Firearm and Nonfirearm Suicides Among U.S. Adults.

内容摘要

Drought is one of the most widespread and disruptive natural hazards globally, with environmental and societal effects that may increase psychological distress. Yet, its association with suicide in the U.S. remains understudied. We examined the relationship between drought and suicide mortality across the contiguous U.S. Drought severity was measured using the Evaporative Demand Drought Index, and suicide data from the National Center for Health Statistics. We used Generalized Additive Models (GAMs) to estimate incidence rate ratios (IRRs) and absolute risk differences (ARDs), with 95% confidence intervals. Analyses were stratified by age, sex, and urbanicity. From 2000 to 2018, the U.S. recorded 350,434 firearm-related and 323,225 non-firearm suicide deaths. Drought affected 37.4% of county-months, and both suicide types were positively associated with drought-especially under severe conditions. For firearm suicides, worsening drought was linked to an IRR of 1.109 (95% CI: 1.091-1.128) and ARD of 0.704 (95% CI: 0.595-0.811); improving drought had an IRR of 1.094 (95% CI: 1.076-1.112) and ARD of 0.608 (95% CI: 0.501-0.715). For non-firearm suicides, worsening drought was associated with an IRR of 1.057 (95% CI: 1.037-1.077) and ARD of 0.347 (95% CI: 0.232-0.461), while improving drought had an IRR of 1.073 (95% CI: 1.054-1.093) and ARD of 0.456 (95% CI: 0.344-0.568). Severe drought was associated with higher suicide mortality, including firearm-related deaths, across several subgroups such as older adults, women, and individuals living in non-metro areas; these subgroup-specific findings were not statistically compared. This study explores how drought, a prolonged period of unusually dry weather, affects suicide rates in the United States. Using data from all counties between 2000 and 2018, we analyzed over 670,000 deaths by suicide to determine if dry conditions were linked to higher risk. We found that both firearm and nonfirearm suicides increased during all stages of drought, with the highest risk seen during the most severe drought periods. Certain groups—including older adults, women, and people living in rural areas—were more affected. The risk was especially high for suicides involving firearms. These findings suggest that dry weather may create or worsen stress, especially for people who are already vulnerable. By better understanding when and where these risks increase, we can improve public health strategies. Adding mental health support to drought preparation and response plans could help save lives, particularly in rural communities and during times of severe environmental stress.