To Örebro University

Experiencing pain, including an emotional reaction, is part of being hu­man. Emotional comorbidity is common in pain patients, and corre­lated to higher symptomatology and worse treatment outcome. The shared vulnerability model suggests that many vulnerability and main­taining factors may be involved in both pain and emotional problems. Hence, they may be transdiagnostic. Since our knowledge about these shared factors is lacking, potential targets for risk assessment, preven­tion, and treatment are likely underutilized. The overarching aim of this dissertation was to further our understanding of comorbid musculo­skeletal pain and emotional problems by investigating the role of trans­diagnostic factors. Specifically, it was studied if levels of shared vulner­abilities (negative affect and anxiety sensitivity) and symptomatology covary in pain patients depending on the occurrence of comorbid social anxiety symptoms (Study I); if peer-related stress predicts musculoskel­etal pain problems over time in adolescents, and if this is mediated by worry and moderated by gender (Study II); and if symptomatology can be decreased in pain patients with comorbid emotional problems by using an internet delivered unified protocol for emotional disorders (Study III). Results show that vulnerabilities covaried with comorbid pain and social anxiety. Also, peer-related stress predicted musculoskel­etal pain problems in adolescents and was mediated by worry for girls. However, the internet-delivered unified protocol did not unequivocally decrease symptomatology. In sum, the studies in this dissertation pro­vide partial support for the role of transdiagnostic factors in comorbid musculoskeletal pain and emotional problems. A transdiagnostic ap­proach may offer a parsimonious understanding of the  development and maintenance of this comorbid symptomatology.