Li DJ, et al. - Among heroin users receiving methadone maintenance treatment (MMT) in Taiwan, researchers examined the factors that can predict new-onset clinically predominant sleep disturbance (CPSD) by analyzing data from 152 people (127 males and 25 females) with heroin use disorder who visited MMT clinics for the first time. Earlier age at onset of heroin exposure, lower attendance rate, greater maximum dose of methadone, and shorter time to maximum methadone dose were significantly related to new-onset CPSD after forward selection in the Cox model. In this 2-year retrospective study, predictors were found that were significantly related to new-onset CPSD, and practitioners should be cognizant of these risk factors for sleep disturbance in heroin users receiving MMT.