In addition, only patients who were seropositive were enrolled because we did not perform the test of myelin oligodendrocyte glycoprotein (MOG) autoimmunity, a distinct spectrum differentiated from seronegative NMOSD, which can limit the generalization of our data to seronegative NMOSD.[41, 42] Finally, other factors including socioeconomic variables that can affect fatigue or QOL,[43] were not investigated in this study, although we completed the comprehensive investigations of possible contributing factors of QOL (fatigue, sleep quality, depression, and pain), in remission. This evidence concerns the gene OMG and major depressive disorder.