Commentary on Maier et al. (2016): Language matters--a call for caution regarding research on non-medical use of prescription drugs.

Abstract

Maier and colleagues' study of purported ‘pharmacological neuroenhancement’ (2015) is difficult to contextualize with prior studies. In the absence of evidence supporting stimulant medications’ cognitive benefits in individuals without diagnosable conditions, researchers should employ conservative terminology such as ‘non-medical drug use’ to avoid perpetuating unsubstantiated beliefs about such benefits, and adopt standardized measures. Maier et al. 1 present the results of a survey of Swiss employees and students that focused on the non-medical use of tranquilizers, antidepressants, attention deficit hyperactivity disorder (ADHD) medications, beta-blockers, modafinil and anti-dementia drugs for self-reported ‘pharmacological neuroenhancement’. Only 411 participants of the 10 171 had used any of these drugs for this purpose in their life-time. Non-medical use was elevated among students, individuals with a mental disorder (including ADHD, depression and anxiety) and individuals reporting poorer health and higher stress levels. This commentary discusses the possible reasons for differences in prevalence estimates across various settings and calls for judiciousness in the way researchers describe non-medical use. The authors place their findings in the context of other surveys conducted in other countries. Comparisons of prevalence estimates are difficult because of the variety of sampling methods used, the survey questions utilized, varying response rates and the characteristics of the individuals surveyed. Population-based estimates from the United States of non-medical use of prescription stimulants are lower than what has been reported in studies of college students from a single campus 2. Even among studies of US college students, these estimates can vary widely 3. Variations in availability and access to treatment, as well as regional differences in prescribing practices of various pharmacological formulations, can also influence prevalence estimates because some formulations are more often used non-medically than others (i.e. immediate versus extended release) 4. In addition to environmental-level conditions, such as availability, non-medical use of prescription drugs, such as the use of any other substance, is driven by a number of individual-level factors (e.g. risk-taking propensity, the balance between one's perception of risk and perception of benefit). An enticing label such as ‘pharmacological neuroenhancement’ as a substitute for a more traditional one such as ‘non-medical drug use’ can amplify public perceptions that non-medical use of these drugs is associated with improvements in cognitive functioning for individuals without a diagnosable condition. For example, while the therapeutic benefit of stimulant medications is established for ADHD patients 5, considerable debate exists regarding extra benefits for individuals without ADHD, especially with regard to executive function 6-8. Even if such effects could be demonstrated for task performance in placebo-controlled laboratory conditions, most agree that there is no evidence that non-medical prescription stimulant users achieve improvements that translate into real-world academic success 6, 9. In fact, nearly every study examining grade point average (GPA) as an outcome of non-medical prescription stimulant use has demonstrated quite the opposite—that non-medical use of prescription stimulants is associated with lower GPAs 3, 10-12. Our group has developed models based on longitudinal data from college students to understand more clearly the precursors of academic decline among non-medical prescription stimulant users. In short, we have found that escalations in excessive drinking and marijuana use appear to precede skipping class and decreases in GPA which, in turn, are associated with the non-medical use of prescription stimulants 10. The significant overlap between all forms of non-medical prescription drug use and other forms of drug use is a robust finding in the literature 3, 4, 13-15, and also observed in Maier's study 1. When prescription drugs are used purportedly for neurocognitive enhancement, it must be considered that the person who is using might be experiencing deficits in cognitive function due to other forms of drug use, and perhaps struggling with an untreated mental health condition. These are underlying problems that deserve our focused attention. Certainly, the motives behind non-medical drug use are interesting phenomena for researchers to understand and explain; but non-medical use of prescription drugs in the current historical context should not be equated with pharmacological neuroenhancement, regardless of purported motives. Perhaps other drugs will be developed in the future that will boost cognitive performance for individuals without a diagnosable condition 16. At a population level, we should continue to develop and use standardized methods for inquiry regarding non-medical prescription drug use. At a clinical level, non-medical use of prescription drugs should be viewed as a possible ‘red flag’ and signal a need for a more comprehensive assessment and possible intervention. None. This commentary was supported by the National Institute on Drug Abuse (NIDA, R01DA014845).