Initiation of nonmedical use of prescription opioids among high school students.

Background: Nonmedical use of prescription opioids (NUPO) is associated with heroin use and other adverse outcomes among adolescents. To inform the timing of substance use prevention activities and which substances to target, we examined age at NUPO initiation, associations between substance use initiation and current (past 30-day) NUPO, and order of NUPO initiation relative to other substances. Methods: Data from 2,834 students aged 15 or older participating in the 2017 Virginia Youth Survey, the first Youth Risk Behavior Surveillance System survey to assess age at NUPO initiation and current NUPO, were analyzed in 2019. Students reported current NUPO and ages at initiation for cigarettes, alcohol, marijuana, and NUPO (categorized as 12 or younger, 13 or 14, 15 or older, or never). Associations between age at substance use initiation and current NUPO were examined using adjusted prevalence ratios (aPRs) and 95% confidence intervals (CIs). Results: Overall, 12% of students reported lifetime NUPO, with 2.4%, 4.0%, and 5.6% initiating at 12 or younger, 13 or 14, and 15 or older, respectively; 5.3% reported current NUPO. Initiating cigarettes, alcohol, and marijuana at each age category (compared with never) was associated with an increased prevalence of current NUPO after adjusting for demographics and initiation of other substances. Among students initiating NUPO, initiating NUPO at 12 or younger (compared with 15 or older) was associated with an increased prevalence of current NUPO after adjusting for demographics (aPR = 1.54, 95% CI: 1.10-2.16), but not after further adjustment for initiation of other substances (aPR = 1.38, 95% CI = 0.97-1.97). Among students initiating NUPO, 45.4% initiated NUPO before or during the same age as other substances. Conclusions: More than 6% of students initiated NUPO at 14 or younger. Younger substance use initiation was associated with current NUPO, suggesting that some students may benefit from prevention activities during early adolescence that address multiple substances.