Do friends' co-rumination and communication with parents prevent depressed adolescents from self-harm?

• Communication with parents and co-rumination with the best friend lower self-harm.
• Only communication with parents buffers the effect of depression on self-harm.
• Depressed girls are less likely to self-harm when communicating with their parents.

This study examines the role of both ease of communication with parents and co-rumination with one's best friend in the link between depressive symptoms and self-harm in a sample of Italian adolescents. Furthermore, it analyzes the possible differences between boys and girls in this link. Questionnaires were administered at a six-month interval at 711 adolescents attending three different schools (Mage = 15.53). Moderation and multiple-group analyses were conducted using a path approach. Results showed both ease of communication with parents and co-rumination with one's best friend decreasing the likelihood of engaging in self-harm. Depressed adolescents were less likely to develop self-harm when they perceived communication with parents as easy. Multiple-group analysis verified this relation only for girls. The findings highlight the importance of interpersonal relationships in decreasing the likelihood of engaging in self-harm, and stress the role of a positive family setting in helping particularly depressed girls not to self-harm.