The Basic Act for Suicide Prevention: Effects on Longitudinal Trend in Deliberate Self-Harm with Reference to National Suicide Data for 1996–2014

A suicide prevention strategy was launched in Japan in 2006 to address the high suicide rate, which had increased considerably since 1998. The national strategy from 2007 involved the enhancement of psychiatric treatment services at emergency medical facilities and supportive observation by individuals close to patients. The national suicide rate has decreased gradually since 2008; however, national information regarding the number of patients who had engaged in deliberate self-harm was absent. Therefore, the present study examined the longitudinal trend in hospital admissions due to deliberate self-harm in Japan. Data from the National Patient Survey between 1996 and 2014—a nationally representative cross-sectional survey of inpatient care every 3 years—were used. Data for 13,014 patients were included in the estimation of the number of hospital admissions due to deliberate self-harm. The results show that the estimated number of admissions due to deliberate self-harm increased from 2078 in September 1996 to 3189 in September 2008, when the national number of suicide cases peaked, and decreased to 1783 in 2014. Approximately half of the patients were admitted to hospital because of self-harm via means other than drug poisoning, which had a high mortality rate (5.6%). The proportion of patients receiving public assistance was higher in those who had engaged in deliberate self-harm (8.5%) relative to that observed in the general population. Overall, the trend in deliberate self-harm was synchronous with the number of suicide cases over time. As economic poverty has been associated with suicidal ideation and behavior and some recipients of public assistance tend to abuse psychotropic medication, the public assistance program should provide mental health support for recipients of social benefit schemes.