Association Between History of Psychiatric Disorder and Degree of Physical Injury Among Suicide Attempters: Secondary Data Analysis in a Japanese Rural Area

INTRODUCTION: While there may be differences in the choice of suicide methods between attempters with and those without a history of psychiatric disorders, it is not clear whether these differences predict the actual degree of physical injury. The present study aimed to investigate the association between the history of psychiatric disorder and the degree of physical injury among suicide attempters in a Japanese rural area. METHODS: We conducted a cross-sectional study analyzing secondary data of 806 suicide attempters from April 2012 to March 2022 obtained from a Japanese rural city. The exposure variable was a history of psychiatric disorders. The primary outcome was the degree of physical injury of suicide attempters: moderate and severe. We conducted a multivariate Poisson regression analysis to estimate the prevalence ratios (PRs) and 95% confidence intervals (CIs). RESULTS: Among 806 suicide attempters, a significant negative association between the history of psychiatric disorder and the degree of physical injury was observed (PR = 0.40; 95% CI, 0.28-0.59). Those with and without psychiatric disorders were more likely to choose low- and severe-lethality suicide methods such as drug or psychotropic overdoses and hanging or deep wrist injuries, respectively (P < .001). CONCLUSIONS: The present study highlights the importance of considering suicide attempters, both with and without psychiatric disorders, while formulating targeted suicide prevention strategies.