How does age of initiation of drugs vary in a national sample of adolescents in relation to use of prescription stimulants

Background: Lifetime (LT) nonmedical use (NMU) (not prescribed or used for the experience or feeling caused) of prescription stimulants (RxStim) has declined since 2002 but remains a problem. The National Survey on Drug Use and Health found that tobacco (T), alcohol (A) and marijuana (M) initiation generally precedes NMU-RxStim; initial age at first medical use of RxStim (MU-RxStim) was not collected. Aim: Data from the National Monitoring of Adolescent Prescription Stimulant Study (N-MAPSS; CottlerLB, PI), collected between October 2008 and February 2011 were used to test the hypothesis that NMU-RxStim users would self-report the youngest first use of T/A/M. Methods: Youth ages 10-18 in 10 US cities and contiguous suburban and rural areas completed an anonymous brief survey on drug use and risk factors. Results: In the sample of 8,219, 52% endorsed LT use of T/A/M [20% one; 15% two, and 17% all three], while 4% (N=349) endorsed LTMU-RxStim and 6% (N=498) endorsed LTNMU-RxStim. LT-RxStim use increased with the number of T/A/M used from 8% among non-users to 41% among those who used all three. RxStim age of initiation differed among NMU-RxStim by T/A/M use: from 12.2 years no T/A/M use to 14.3 years for all three T/A/M, significantly later than for those with MU-RxStim. Conclusions: Youth who had used T/A/M were more likely to report MU-RxStim or NMU-RxStim, which could reflect a shared liability. T/A/M use may reflect an attempt to self-treat attentional problems, delaying initiation of RxStims. Patterns and trajectories of drug use in adolescents should include RxStims.