Simon CB, Valencia C, Coronado RA, et al. - Researchers' prior work suggested that among individuals undergoing shoulder surgery for shoulder pain, the chance of not reaching a 12-month pain recovery criterion is nearly double among individuals categorized as having a high-risk phenotype (comprised of COMT variation and pain catastrophizing). Via this study, they sought to better understand the development of persistent postoperative shoulder pain via investigating temporal ordering of postoperative shoulder recovery based on potential mediating factors, and expansion of outcomes to include movement-evoked pain and shoulder active range of motion. Categorization of individuals was done before surgery as either high-risk (high pain catastrophizing, COMT-genotype linked to low enzyme activity [n = 41]) or low-risk (low pain catastrophizing, COMT-genotype linked to normal enzyme activity [n = 107]). Risk subgroups exhibited similar shoulder active range of motion recovery. Higher fear and movement-evoked pain were reported at 3 months in the high-risk subgroup, and the direct effect of risk subgroup on 12-month movement evoked pain was confirmed by causal mediation analysis. However, there appeared mediatory role of baseline to 12-month change in depressive symptoms in 53% of the total effect of risk subgroup on 12-month movement-evoked pain.