Exploring suicide risk factors among Japanese individuals: The largest case-control psychological autopsy study in Japan.

This case-control psychological autopsy study explored suicide risk factors among Japanese individuals. We targeted 102 suicide completers over 20 years of age and 334 living controls matched to suicide cases by gender, age, and residential municipality in Japan. After controlling for other factors, we found significant associations between suicide and mental disorders, sleeping problems, and verbal communication of one's own death. We discuss the importance of sensitive responses to verbal expressions of suicidal ideation.