Self-harming behaviors, such as eating disorder behaviors, self-injury, and suicide, rarely occur in the research lab and researchers cannot ethically induce these behaviors in traditional research settings to study them. Therefore, we lack a clear understanding of many fundamental properties of these behaviors and how the occur in the real world, in real time. To address this gap, my research in this area aims to leverage advances in smartphone technology and wearable biosensors to improve the understanding and prediction of eating disorder behaviors, nonsuicidal self-injury, and suicidal thoughts and behaviors.