 Engagement in non-suicidal self-injury NSSI, purposefully harming oneself without the conscious intent to die such as cutting or burning, is pervasive among adolescents. Lifetime prevalence estimates among community samples of high school students range from 13.0 to 23.2. Despite the significance of this public health problem, there are no known interventions that successfully reduce the frequency of NSSI or prevent NSSI in adolescents. The goal of the current study is to develop an effective psychosocial intervention for NSSI among adolescents who are engaging in self-injury and have a depressive disorder. Specifically, we will amend Interpersonal Psychotherapy for Depressed Adolescents IPT-A, a psychotherapy that has demonstrated efficacy in treating depressed adolescents Mufson et al., 1994, 1999, 2004, for use with adolescents with depression who are engaging in NSSI, with the ultimate goal of curing the depression and NSSI. Ten participants will be administered IPT-A and assessed several times throughout the course of the trial. It is expected that IPT-A will be a useful treatment for co-morbid depression and self-injury, although adaptations to the protocol will likely be needed to address the behavioral aspect of the self-injury. Data analyses will be descriptive in nature and involve examining the individual trajectories of depression and NSSI over time. The data obtained from the current study will lay the groundwork for an ultimate randomized controlled trial in which we plan to compare IPT-A versus nondirective supportive therapy in the treatment of co-morbid depression and NSSI. 