A systematic review of the motivations for the non-medical use of prescription drugs in young adults

Highlights

• Young adults are most at-risk for the non-medical use of prescription drugs (NMUPD).

• A systematic review of motivations for NMUPD in individuals ages 18–25 was conducted.

• Results revealed that much of the work is limited in scope (e.g., college students).

• Using drugs for their generally known effects and recreational motives were popular.

• Inconsistent terminology and temporal issues are current concerns in this literature.

Abstract

Background

Young adults (18–25) are most at-risk for the non-medical use of prescription drugs (NMUPD). Understanding this population's motivations for use can help inform efforts to reduce NMUPD. Therefore, this systematic review synthesizes the findings from research on young adults' motivations to engage in NMUPD.

Methods

Based on PRISMA guidelines, relevant databases were systematically searched for articles that assessed the motivations for NMUPD in young adults and college-aged students. Search strings included a range of prescription drug classes and terms to ensure an exhaustive review.

Results

The search resulted in identifying 353 potential articles after duplicates were removed, and 37 articles were included in the final qualitative synthesis. Of the final articles, the majority investigated the non-medical use of prescription stimulants in U.S. student populations cross-sectionally. Seven studies, either exclusively or in combination with other medications, researched prescription opioids, and five investigated central nervous system depressants. Only one study investigated motivations over time.

Conclusion

There are many ways in which the current literature can be expanded, including researching other populations and focusing on prescriptions other than stimulants. Using the medications for their prescribed properties and known side effects emerged as a consistent theme. It was also fairly common for young adults to report recreational motives. Issues with measurement and definitions of key terms (e.g., non-medical) would benefit from consistency in future work. Research on motivations should continue and be incorporated into the larger drug use context, as well as existing prevention and intervention strategies.

Introduction

The non-medical use of prescription drugs (NMUPD) is a significant and growing public health concern with young adults at great risk for use, abuse, and related negative outcomes (e.g., National Institute on Drug Abuse (NIDA, 2011). According to NIDA, NMUPD occurs when individuals either use medications that were not prescribed to them, use their prescribed medications in higher quantities or manners other than prescribed, or take medications for purposes other than prescribed (e.g., to get high; NIDA, 2014). The types of prescription drugs used for non-medical purposes most often are stimulants, opioids, and central nervous system (CNS) depressants (NIDA, 2011).

As a population characterized by instability and experimentation, young adults (ages 18–25) are clearly an at-risk group for substance use (Arnett, 2005). It is during young adulthood that, on average, people report initiation of illicit substance use, including NMUPD (SAMHSA, 2013b). Young adults exhibit the greatest illicit drug use compared to all other age groups in the United States (SAMHSA, 2013b). Additionally, within the twenties is the mean age for onset of NMUPD disorders, and for seeking treatment for these disorders (Huang et al., 2006). Further, there is evidence suggesting that adolescent decision-making is different than that of young adults, which is different from older adults, as a result of brain development (for a reviews see Spear, 2013, Steinberg, 2008). Consequently the motivations to engage in NMUPD, and the interventions targeting NMUPD, will likely vary by age. Therefore, this review focuses on the developmental period of young adulthood, the population considered most at-risk.

NMUPD is the second most commonly reported form of illicit substance use by young adults, after marijuana (SAMHSA, 2013b). This is a growing public health concern. For example in 2014, 884,000 young adults engaged in NMUPD for the first time in the past year (Lipari et al., 2015). In full-time college students (ages 18–22), NMUPD initiation peaked with an average of 850 new users per day for prescription opioids alone in 2013 (Lipari, 2015). More people have also been seeking treatment for prescription opioid abuse, with rates for young adults increasing by approximately 26% from 2002 to 2010 (SAMHSA, 2011).

NMUPD has been linked with abuse and dependence (Huang et al., 2006, Hurwitz, 2005, Kroutil et al., 2006; SAMHSA, 2013b), and a variety of other negative outcomes in young adults, including mental illness (Arria et al., 2008, Bavarian et al., 2013, Janusis and Weyandt, 2010, Lo et al., 2013, McCauley et al., 2009, McCauley et al., 2010, McCauley et al., 2011, Van Eck et al., 2012, Zullig and Divin, 2012), increasing number of emergency room visits (SAMHSA, 2013a,b), a risk factor for arrest and delinquency (Drazdowski et al., 2015, Herman-Stahl et al., 2007), and more unintentional overdose deaths (Paulozzi, 2012). Additionally, young adults who engage in NMUPD are significantly more likely than their peers to use other illicit drugs and to combine prescription drugs with alcohol and other substances, which increases the risk of potentially dangerous drug interactions and their negative outcomes (Garnier et al., 2009, McCabe et al., 2006; SAMHSA, 2006). Of particular concern for young adults in collegiate settings, many students who endorsed the non-medical use of prescription stimulants and opioids also reported spending less time studying, skipping classes more often, earning lower grades (Arria et al., 2008), and more frequent sexual risk behaviors (Benotsch et al., 2011). Clearly NMUPD, particularly by young adults, is a large and growing public health problem with significant consequences.

Unfortunately, the majority of individuals with NMUPD disorders never receive treatment for their drug use problems or any mental health issues (Huang et al., 2006). One way to prevent substance use is to investigate why specific groups of people use and to target interventions specifically to certain predictors. One of these factors, on the individual level, is the motivations for why young adults decide to engage in NMUPD. Although it is only one small piece of the etiology for drug use and abuse, and needs to be considered along with other factors such as molecular genetics, personality patterns, culture, etc. (see Kendler, 2012); motivations can be self-reported and are amendable to change (e.g., Miller et al., 1993). Previous research supports that motivations for substance use are important predictors of use patterns and problems in young adults. For example, drinking motivations have been found to predict alcohol consumption and alcohol-related problems in young adults and adolescents (Kuntsche et al., 2005), as well as mediate or moderate environmental and individual variables with alcohol-related outcomes in these populations (Cooper et al., 2000, Magid et al., 2007, Kuntsche et al., 2010, Kenney et al., 2014). Research investigating motivations in young adults supports that similar patterns exists for NMUPD. For example, varying NMUPD motivations have been linked with diverse use outcomes, including likelihood of binge drinking, using other illicit substances, and screening positive for drug and alcohol abuse (McCabe et al., 2009).

Since different motivations relate to different patterns of use and outcomes, prevention and intervention efforts will likely need to be targeted to most effectively address the individual's needs based on their specific motivations for use. For instance, an individual reporting addiction as a motive may need different treatment than an individual reporting recreational motives, like to have fun. Additionally, motivations have been recognized by SAMHSA as an important treatment target (SAMHSA, 2013c). Therefore, this review examines studies that have investigated young adults’ motivations to engage in NMUPD. Based on a systematic review, the research that has been conducted to date is presented by prescription drug class and followed by a critical analysis and discussion of directions for future research.