Global Perspectives of Seasonal Changes of Suicide and Associations between Suicide and Weather

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K19773
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Psychiatric science
• Research Institution: The University of Tokyo (2018); Nagasaki University (2016-2017)
• Principal Investigator: Kim Yoonhee 東京大学, 大学院医学系研究科(医学部), 准教授 (40746020)
• Research Collaborator: Hashizume Masahiro ; Honda Yasushi
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: Suicide / Temperature / Season / Multi-country

Outline of Final Research Achievements

Although many previous studies have reported that higher temperature is associated with increases in the risk of suicide, there has been limited evidence of estimating the exact nonlinear temperature-suicide association. Thus, we aimed to examine the nonlinear temperature-suicide association across 341 locations in 12 countries comprehensively by using a unified analytical approach.
Our results showed that in general the risk of suicide increased as temperature increases, but it was leveled off at extremely high temperature. Also, we identified a critical range of temperatures that maximize the risk of suicide based upon the nonlinear curves of the temperature-suicide association.
This study would give a better understanding of suicide epidemiology and suggests a new perspective on how to implement suicide prevention programs at a population level. It can also help in generating future projections of mortality burdens from suicide under climate change.

Free Research Field

Environmental Epidemiology

Academic Significance and Societal Importance of the Research Achievements

本研究は、気温 - 自殺の短期的関連を明らかにする大規模観察疫学研究であり、自殺率の高い人口集団における気候変動の健康影響評価に重要な示唆を提供する。
本研究は、気温 - 自殺の関係の理解を深め、自殺予防のための予測モデル構築の基礎資料となる。また、気候変動により今後猛暑日の増加が予測されているが、精神健康保健領域における疾病負荷の推定に、より正確で洗練されたモデルの構築と推計法が必要であることを示唆する。