A crucial approach to devise and consider urgently needed suicide-prevention measures based on suicide trends over 27 years in Japan

Japan's mortality rate from suicide remains high globally for both males and females,^1,2 and the necessity of identifying and implementing more effective suicide-prevention measures in Japan has been emphasized.^3,4 Before 2006, Japan's suicide-prevention measures focused primarily on the “early detection of and measures to deal with depression.” Japan's government enacted the Basic Act on Suicide Prevention in 2006, formulated the General Principles of Suicide Prevention in 2007, formulated the Plan to Accelerate Measures to Deal with Suicide in 2008, finalized the Emergency Plan to Save Life and Deal with Suicide in 2010, subsequently formulated the second (2012), third (2017), and fourth (2022) iterations of the General Principles of Suicide Prevention, and amended the Basic Act on Suicide Prevention in both 2016 and 2025.^1,2,5

Suicide must therefore be thoroughly understood in order to truly resolve the issues related to suicide and reduce the rate of suicides in Japan. Toward that end, the suicide trends since 1998—when the country's suicide rate abruptly increased—must be ascertained, and particular attention needs to be paid to changes in key suicide-prevention measures and aspects when preventive measures are being considered.

As part of these efforts to combat suicide, we researched the total number of suicides in Japan and the suicides by males and females during the period 1998–2024 based on only official numerical data without individual information from the National Police Agency, and we calculated the ratio of suicides among females to those among males. ⁶ Our study divided this 27-year era into Period 1 (1998–2010), Period 2 (2011–2019), and Period 3 (2020–2024) to clearly delineate changes in suicide trends and key aspects of the changes in suicide-prevention measures that are needed.

The total number of suicides over the 27-year era was 747,986 overall, with 523,928 by males and 224,058 by females. The number of suicides annually ranged from 20,169 overall in 2019 to 34,427 in 2003. Suicides by males ranged from 13,801 in 2024 to 24,963 in 2003, and suicides by females ranged from 6091 in 2019 to 9850 in 1998. The female/male ratio over the 27-year era was 0.428. The female/male ratio in each year ranged from 0.379 in 2003 to 0.507 in 2021. The female/male ratio in Period 1 ranged from 0.379 in 2003 to 0.428 in 1998. In Period 2, it ranged from 0.433 in 2019 to 0.463 in 2011. In Period 3, it ranged from 0.469 in 2023 to 0.507 in 2021. These results revealed that the female/male ratio of suicides increased from Period 1 to Period 2 and from Period 2 to Period 3.

During Period 1, the number of suicides by middle-aged men in particular increased, due primarily to economic and life problems. ⁷ During Period 2, the suicide rate among middle-aged and elderly individuals decreased markedly; the suicide rate among younger individuals tended to decrease, but it began increasing in the latter half of Period 2.^6,8 Period 3 was characterized by an increase in or a similarly high level of suicide among younger people. We have paid particular attention to sustained trends in suicide among younger women.^6,9 In 2024, there were more suicides by females in their late teens than by males in their late teens. ¹⁰ Among younger people who committed suicide in 2022–2024, ∼20% of males and ∼40% of females had previously attempted suicide. Most of the suicide attempts by females involved a drug overdose. ¹⁰

These findings indicate that the key focus of suicide-prevention measures in Japan changed over the 27-year period 1998–2024. This change was not sudden; rather, it occurred over a specific period of time. An effective approach to suicide-prevention measures in Japan has been to “devise preventive measures with a focus on the sex and age group of individuals that are increasingly committing suicide” and “[consider] preventive measures for the sex and age group of individuals that are increasingly committing suicide.” ⁹ In other words, it is crucial to devise suicide-prevention measures for younger women and for female junior high school and high school students in the present. Such measures for both male and female elementary, junior high school, and high school students are also crucial. Medical personnel, government personnel, the police, and related agencies must work together to address suicide prevention in these populations. In order to ascertain suicide trends, analyze them, and devise preventive measures, a medical approach, and especially one from social medicine, is required.