Elsevier

Drug and Alcohol Dependence

Volume 152, 1 July 2015, Pages 224-229
Drug and Alcohol Dependence

Full length article
Peak ages of risk for starting nonmedical use of prescription stimulants

https://doi.org/10.1016/j.drugalcdep.2015.03.034Get rights and content

Highlights

  • Data are from the United States National Surveys on Drug Use and Health 2004–2012.

  • A meta-analytic approach was used to identify ages of peak risk of initiation.

  • Risk estimates for nonmedical stimulant use are age-, year-, and cohort-specific.

  • Peak risk was concentrated between ages 16 and 19 years among young people.

  • Females were more likely to have started nonmedical use of prescription stimulants.

Abstract

Background

To produce population-level, year- and age-specific risk estimates of first time nonmedical use of prescription stimulants among young people in the United States.

Methods

Data are from the National Surveys on Drug Use and Health 2004–2012; a nationally representative probability sample survey administered each year. Subpopulations included youths aged 12 to 21 years (n = 240,160) who had not used prescription stimulants nonmedically prior to their year of survey assessment. A meta-analytic approach was used to produce population-level age-, year-, and cohort-specific risk estimates of first time nonmedical use of prescription stimulants.

Results

Peak risk of starting nonmedical use of prescription stimulants was concentrated between ages 16 and 19 years, when an estimated 0.7% to 0.8% of young people reported nonmedical use of these medicines for the first time in the past twelve months. Smaller risk estimates ranging from 0.1% to 0.6% were observed at ages 12 to 15 years and 20 to 21 years. Compared with males, females were more likely to have started nonmedical use of prescription stimulants (odds ratio = 1.35; 95% CI, 1.13–1.62), particularly between the ages of 14 and 19. Females showed a peak annual incidence rate of 1% at age 18, while males the same age showed an incidence rate of 0.5%.

Conclusions

Peak annual incidence rates for nonmedical use of prescription stimulants were observed between the ages of 16 and 19 years. There is reason to initiate interventions during the earlier adolescent years to prevent youths from starting nonmedical use of prescription stimulants.

Introduction

Many nationally representative studies reporting past-year and lifetime prevalence rates for nonmedical use of stimulants do not differentiate between first time nonmedical use and nonmedical use that persists years after onset (i.e., use of prescription stimulants that were not prescribed to the user or that the user took only for the experience or feeling they caused). Past-year and lifetime prevalence rates for nonmedical use are informative, but ultimately may convey more information about persistence in nonmedical use than the timing of initiation among youth. To produce reliable age-specific incidence rates for nonmedical use (i.e., peak ages of onset), it is necessary to separate first-time users from sporadic or persistent nonmedical users by excluding the latter from the sample, or by separately analyzing data from these two different types of users (Austic et al., in press, Deandrea et al., 2013, Harris et al., 2008, Meier et al., 2012). The present study is one of only a few to estimate peak age of onset for nonmedical use (Austic et al., in press, Deandrea et al., 2013, Meier et al., 2012), and is the only nationally representative study to produce age-specific incidence rates for nonmedical use of stimulants among young people in the United States (US). Age-specific incidence rates for youth provide crucial information needed to design timely and effective primary prevention initiatives because they identify ages of lower risk directly preceding ages of peak risk for starting to misuse another person's prescription or misuse one's own prescription without a physician's knowledge (Deandrea et al., 2013). Nationally representative studies such as the Monitoring the Future have been criticized for lack of specificity in questions asked about different types of prescription stimulants (e.g., just asking about stimulants prescribed to treat attention deficit/hyperactivity disorder (ADHD; Rabiner, 2013). Since 1999, the National Survey on Drug Use and Health (NSDUH) has used a confidential multi-item nonmedical stimulant use assessment featuring color photographs of different formulations of prescription stimulants including but not limited to ADHD medication (Substance Abuse and Mental Health Services Administration (SAMHSA), 2014). While the NSDUH is not without limitations (Boyd and McCabe, 2008), NSDUH estimates are strong relative to available alternatives. Each year the NSDUH is administered to a new nationally representative sample of the US population and asks about past-year and lifetime nonmedical use of a broad range of prescription stimulants. In contrast with studies reporting mean age of onset (see results from the 2012 NSDUH study, Substance Abuse and Mental Health Services Administration (SAMHSA), 2013a), the present study uses a meta-analytic approach that treats each NSDUH year's independent sample – from 2004 to 2012 – as a separate study to identify peak ages at which young people in the US are most likely to start nonmedical use of prescription stimulants (i.e., first time nonmedical use in the past-year; Austic et al., in press, Deandrea et al., 2013, Harris et al., 2008, Meier et al., 2012). Based on epidemiological estimates previously published, it was anticipated that the present study would identify a peak risk for first time nonmedical use of prescription stimulants starting during the early college years (McCabe et al., 2014, McCabe and West, 2013).

Section snippets

Study setting and data collection

Data are from the 2004 through 2012 National Survey on Drug Use and Health (NSDUH) with annual independently drawn nationally representative probability samples of US community residents age 12 years or older. The NSDUH sampling frames include youth who drop out of school and youth who attend school. Participation levels for 12 to 25 year old participants were acceptable, at 70% or better during the years under study (Substance Abuse and Mental Health Services Administration (SAMHSA), 2014).

Newly incident user characteristics

Table 1 describes the study sample and reports unweighted frequencies and weighted proportions for subgroupings of newly incident users based on demographic characteristics. The main study estimates given in Table 2 are weighted proportions of newly incident prescription stimulant users. These estimates include a tracing of individual cohorts, age-specific patterns, and age-year-cohort patterns of concentrated risk. For example, an estimated 0.4% of respondents who were aged 14 years in 2004

Discussion

In this article, the results are reported from a meta-analysis on the relationship between age and risk of starting nonmedical use of stimulants among young people in the United States. Between the ages of 12 and 21, 1232 (5%) of the 240,160 youths surveyed who had not used prescription stimulants nonmedically prior to their year of survey assessment reported that they had begun such use for the first time in the past year. The peak years of risk for first time nonmedical use of prescription

Conclusion

Results from this nationally representative, meta-analytic study indicate that peak annual incidence rates for nonmedical use of prescription stimulants among youth aged 12 to 21 were between the ages of 16 and 19 years. Due to the relatively low annual incidence rates observed, screening-based intervention programs may be cost prohibitive. These results draw attention to the timing of potential school-based and practice-based initiatives. If these initiatives are started in early adolescence,

Role of funding source

Nothing declared. The development of this article was supported by National Institute on Drug Abuse grants R01DA024678, R01DA031160, R01DA016558, K05DA015799, T32DA021129, T32DA007267, and National Institutes of Health grant 2UL1TR000433-06.

Contributors

None (sole author manuscript).

Conflict of interest

No conflict declared.

Acknowledgement

A preliminary version of this work drawing upon 2004–2010 NSDUH data was accepted for presentation at the 2012 annual meeting for the College on Problems of Drug Dependence.

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