Nonsuicidal self-injury (NSSI) among young people--most notably in the form of forearm- or wrist-cutting--occurs across cultural groups, social strata, and developmental stages, puzzling and repelling adults. Youth engaging in NSSI behaviors are at a higher risk for suicidality as well as other mental health and academic problems. And because NSSI is often first noticed in the school setting (as is the case with many children's disorders), school...