An analysis of secular trends in method-specific suicides in Japan, 1950-1975

Double suicide in Japan in the post-war reconstruction period, with reference to contemporary Japan

After Japan's post-war reconstruction, in the early 1950s, cases of double suicide, in which two people (particularly young lovers) leave a suicide note and die together, were a relatively frequent occurrence. During the three-year period between 1954 and 1956, 5466 suicides were recorded in the special wards of Tokyo, including 79 cases of double suicides, accounting for 158 deaths. In these double suicide cases (2.89% of all deaths by suicide), the evidence revealed that 65.8% involved lovers and 29.1% involved married couples. By contrast, contemporary data indicate a large drop in suicide pacts between lovers to 15.9% and an increase between spouses to 48.8%. Conceivably, the relatively high double-suicide rate after post-war reconstruction reflected difficulties for the younger generation in reconciling 'marriage based primarily on love' and the traditional family system, specifically marriage problems and stress caused by rapidly changing post-war values. One notable difference between victims of double suicide in 1954-1956 and the contemporary period is the younger average age of the former. Another important shift was found in the most common causes of death among victims of double suicide: in 1954-1956 these were poisoning by cyanide or hypnotic drugs, compared to carbon monoxide poisoning and hanging in modern times. We discuss similarities and differences concerning double suicides in relation to social and economic conditions in Japan in the 1950s and today.

Age, period, cohort trends of suicide in Japan and Korea (1986-2015): A tale of two countries

Japan and South Korea have among the highest suicide rates in the world. However, the age, gender, and time trends in each country differ substantially. Age-Period-Cohort (APC) analysis of suicide rates was conducted to better understand these differences. Using age- and gender-specific data on suicide between 1986 and 2015 in Japan and Korea, we implemented APC analysis to decompose the country-specific trends into age, calendar period, and birth cohort effects. APC analysis revealed three trends: (1) there was a sharp increase in suicide around retirement age in Korea but not in Japan (age effect); (2) there was a dramatic increase in suicide during the three decades of observation in Korea (period effect) whereas rates were more stable in Japan; and (3) the post-War generation in Japan (including baby boomer) had lower rates of suicide compared to generations born before 1916 or after 1961 (birth cohort effect), whereas suicide rate has increased linearly in each generation in Korea. Although Japan & Korea share high suicide rates, our APC analysis suggests divergent causes underlying these trends. Japanese suicide rates plateaued among the cohorts who experienced the post-War rapid economic growth (women born in 1951-1956 and men born in 1916-1961) (birth cohort effect) due to a strong social safety net for this cohort, while suicide rates in Korea continue to rise with each generation and is particularly elevated in post-retirement age. Japan and Korea need to pay more attention to suicide prevention in more recent birth cohorts.

Trends in Suicide Mortality by Method from 1979 to 2016 in Japan

Suicide is a major public health concern in Japan. This study aimed to characterize the trends in suicide mortality in Japan by method since 1979. Using data from the Japan vital registration system, we calculated age-standardized rates of suicide mortality separately by sex and method. We conducted a log-linear regression of suicide mortality rates separately by sex, and linear regression analysis of the proportion of deaths due to hanging, including a test for change in level and trend in 1998. While crude suicide rates were static over the time period, age-adjusted rates declined. The significant increase in suicide mortality in 1998 was primarily driven by large changes in the rate of hanging, with suicide deaths after 1998 having 36.7% higher odds of being due to hanging for men (95% CI: 16.3–60.8%), and 21.9% higher odds of being due to hanging for women (95% CI: 9.2–35.9%). Hanging has become an increasingly important method for committing suicide over the past 40 years, and although suicide rates have been declining continuously over this time, more effort is needed to prevent hanging and address the potential cultural drivers of suicide if the rate is to continue to decline in the future.