No evaluations of the efficacy of Mend exist. The strategies contained within Mend are follow recommendations for therapeutic interventions following heartbreak as advocated by Fisher and colleagues (2016). This includes adopting interventions similar to those used in addictions such as self-expanding exercises (Xu et al., 2010) or mindfulness-based approaches that aim to alleviate the symptoms of heartbreak that align with addiction (i.e. cravings, relapse, and withdrawal). Therefore, Mend appears to contain some evidence-based principles, but would benefit from formal evaluation.
Fisher, H. E., Xu, X., Aron, A., & Brown, L. L. (2016). Intense, passionate, romantic love: a natural addiction? How the fields that investigate romance and substance abuse can inform each other. Frontiers in psychology, 7.
Xu X., Floyd A. H. L., Westmaas J. L., Aron A. (2010). Self-expansion and smoking abstinence. Addict. Behav. 35 295–301.