Prevalences of lifetime histories of self-cutting and suicidal ideation in Japanese adolescents: differences by age.

We examined differences in the prevalence of a lifetime history of self-cutting and suicidal ideation by age among junior and senior high-school students. Histories of self-cutting and suicidal ideation were reported by 9.9% and 40.4% of the students. Among early teens, females were more likely to report suicidal ideation than males, and among late teens, females were more likely than males to report self-cutting.