The present review examines psychosocial factors emerging as predictive of clinical outcomes among solid organ transplant (SOT) recipients, with possible extensions to vascular composite allograft (VCA) and hand transplantation, in particular. The Chauvet Workgroup report and International Society of Heart and Lung Transplantation consensus guidelines are used to delineate areas of commonality between SOT and VCA, as well as unique features contributing to post-VCA psychosocial risk. Increasing evidence suggests that depression, cognitive function, and other posttransplant psychosocial factors consistently associate with clinical risk in SOT. However, the mechanisms precipitating these psychosocial risk factors are likely diverse in their cause, with large individual differences across SOT and VCA. Transdiagnostic dimensions may serve as mechanistic factors, increasing the risk of adverse clinical outcomes and suggesting potential treatment strategies for risk mitigation. Psychosocial dimensions including psychological flexibility, self-efficacy, and posttraumatic growth are discussed as potential contributory factors. Psychosocial factors hold importance in predicting posttransplant clinical outcomes. Emerging transdiagnostic factors may provide insight into mechanisms and potential treatments.