Objectives. This study investigates vulnerabilities to deliberate self-harm (DSH) among adolescents, specifically focusing on peer victimisation and alexithymia.

Design. Correlational survey design.

Methods. Three hundred and twenty-five secondary school students completed self-report questionnaires asking their history of DSH and bullying, and scales assessing alexithymia and depression.

Results. Self-harming adolescents reported more victimization and alexithymic symptomology than participants who had never engaged in DSH. Alexithymia moderated, and partially mediated, the relationship between bullying and DSH. Bullying and DSH significantly co-varied when participants' alexithymia was moderate or high, but not when participants' alexithymia was low. The relationship between alexithymia and DSH was fully mediated by depression. The relationship between bullying and DSH was also moderated by depression. Depression moderated the relationship between alexithymia and DSH.

Conclusions. The findings suggest stressors in the social environment (e.g. bullying) are more likely to facilitate DSH when an adolescent has poor emotion regulation and communication skills and when an individual is experiencing mood difficulties.