Global Perspectives of Spatial and Temporal Variations in Seasonality of Suicide and Temperature-Suicide Association

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K17104
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52030:Psychiatry-related
• Research Institution: The University of Tokyo
• Principal Investigator: Kim Yoonhee 東京大学, 大学院医学系研究科(医学部), 准教授 (40746020)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: Suicide / Temperature / Season / Multi-country

Outline of Final Research Achievements

Literature suggests that suicide risk varies seasonally, and there is a growing body of evidence reporting a short-term temperature-suicide association. High levels of temperature increase suicide risk. However, there is a lack of understanding of which local characteristics may modify the suicide seasonality and the temperature-suicide relationship, or whether the association may change over time.

We collected and analyzed daily time-series data across 408 locations in 26 countries using a unified statistical modeling approach. We found that a temperature-suicide relationship exists, and that the seasonality of suicides and the temperature-suicide relationship varied by local characteristics. However, there was no clear evidence that the suicide seasonality and the temperature-suicide relationship varied over time. This study has important implications for assessing the health impacts of climate change in populations with high suicide rates.

Free Research Field

Environmental Epidemiology

Academic Significance and Societal Importance of the Research Achievements

本研究は自殺の季節性と気温―自殺の短期的関連性を明らかにした大規模な観察疫学研究であり、自殺率が高い人口集団で気候変動と健康影響評価に対する重要な保健学的視点を提供する。特に、気候変動による精神健康影響評価の必要性と気候変化による爆炎及び熱帯夜から生じうる精神疾患負荷推定において、より正確なモデル構築と計算方法が必要であることを示唆する。研究結果を通して、科学的根拠は持続的な方法論の発展を図り、未来の気候変動による精神疾患影響緩和及び適応政策にも役に立つと期待される。最終的に自殺予防による予測モデル構築に寄与すると期待される。