Research Paper
Pharmacological cognitive enhancement among non-ADHD individuals—A cross-sectional study in 15 countries

https://doi.org/10.1016/j.drugpo.2018.05.009Get rights and content

Highlights

  • This is the largest global study on substance use for cognitive enhancement with >100,000 participants.

  • The findings indicate that PCE with prescription and illegal stimulants has increased among survey participants.

  • The increase in PCE is highest in European countries, while rates in the U.S. and Canada constantly remain high.

  • Methylphenidate is the most popular drug for PCE in Europe, while Modafinil is first in the UK and Adderall™ in the U.S.

  • Countries with more liberal drug policies showed lower rates of PCE with illegal stimulants with potentially greater health risks.

Abstract

Background

Psychoactive substance use aiming at increased performance at work or while studying, usually referred to as pharmacological cognitive enhancement (PCE), has been extensively researched in recent years. While large scale national studies have tried to assess the prevalence of PCE among the general population, cross-cultural comparisons have been hampered by the different definitions and designs included. In addition, the non-medical use of prescription drugs indicated to treat the symptoms of the Attention Deficit Hyperactivity Disorder (ADHD) has been the focus of discussion, yet no study has addressed the association between ADHD rates, prescribing behaviour and PCE yet.

Methods

The Global Drug Survey is an annually conducted anonymous web survey on substance use. Two data sets from male and female Global Drug Survey (GDS) participants aged 16 to 65 years with no previous ADHD diagnosis were analysed to assess12-month PCE in 15 countries. GDS2015 (n = 79,640) examined the patterns of and motives for stimulant PCE, while GDS2017 (n = 29,758) focused on both the use of stimulant and sedative drugs for PCE

Results

When comparing the study samples 2015 and 2017, PCE with prescription and illegal stimulants and modafinil increased across all countries. People who used stimulant drugs and modafinil for PCE rated the perceived effect on cognitive performance most beneficial, while alcohol was the substance with the most adverse effect.

Conclusion

The analysis of data on stimulant use for PCE in the largest global sample highlights relatively low-risk PCE use patterns except for participants with illegal stimulant use for PCE. The globalisation of ADHD, physicians’ prescribing behaviour and changes in drug policy are likely to influence the country-specific rate of PCE among non-ADHD individuals what calls for further investigation.

Section snippets

Background

Pharmacological cognitive enhancement (PCE), refers to the use of prescription drugs, alcohol and illegal drugs for the purpose of improved performance at work or while studying and has become an increasing area of debate and research (Maier & Schaub, 2015; Maslen, Faulmüller, & Savulescu, 2014). Media articles portrayed PCE among healthy students as common and increasing (Partridge, Bell, Lucke, Yeates, & Hall, 2011), while scientific evidence for such an increase remained weak, (Maier &

The global drug survey (GDS)

The GDS is a cross-sectional anonymous web survey on substance use behaviour widely promoted by a range of media partners including national newspapers, magazines, websites, and social media (Barratt et al., 2017). Each year between November and January the following year, GDS recruits a non-probability sample of respondents, 16 years and over, who have recreationally used legal and/or illegal drugs. The core questionnaire consists of an extensive substance use screen assessing patterns of use,

Sample characteristics

The sample characteristics, by GDS year, are provided in Table 1. Across both years, there were more male than female respondents. The mean age of the sample from 15 countries for GDS 2015 was 29 years (SD = 10.6) and for GDS 2017 was 31 years (SD = 11.9). Roughly one third of the sample from either GDS year were from Germany, the distribution of the sample from other countries ranged between 0.6% (France, GDS 2017) and 12.0% (USA, GDS 2017). From the GDS 2015 sample, two fifths of participants

Discussion

This is the largest study on PCE that has ever been conducted. Data from more than 100,000 participants from 15 countries were collected as part of Global Drug Survey 2015 and 2017. Overall, 4.9% and 13.7% of the global sample reported the 12-month use of prescription or illegal stimulants and/or modafinil to improve the performance at work or while studying. This is on average an increase of 180% that can not only be explained by the self-selection of the sample and the different wording of

Conclusion

The analysis of stimulant use for PCE in the largest global sample shows relatively low-risk PCE use patterns except for participants who recently used illegal stimulants for PCE with no or insufficient access to prescription stimulants. The globalisation of ADHD and related medical treatment (Singh et al., 2013) is likely to influence the country-specific rate of PCE among non-ADHD individuals and needs further investigation. Policy-makers should utilize the best available scientific evidence

Conflict of interest

ARW is the founder and owner of Global Drug Survey. LJM and JAF are part of the Global Drug Survey Core Research Team but have no conflict of interest.

Acknowledgments

Global Drug Survey Ltd is an independent self-funded survey. The authors received no financial support for the preparation and/or publication of this article. The authors would like to thank Emma Belton and Renee Zahnow for their input on how to best include the new data from the second period of data collection. Most importantly, the authors would like to thank the collaborating global media partners and the study participants who have answered the questions in the module on substance use for

References (50)

  • K. Benson et al.

    Misuse of Stimulant Medication Among College Students: A Comprehensive Review and Meta-analysis

    Clinical Child and Family Psychology Review

    (2015)
  • W.M. Compton et al.

    Prevalence and correlates of prescription stimulant use, misuse, use disorders, and motivations for misuse among adults in the United States

    American Journal of Psychiatry

    (2018)
  • P. Dietz et al.

    Randomized response estimates for the 12-month prevalence of cognitive-enhancing drug use in university students

    Pharmacotherapy

    (2013)
  • P. Eickenhorst et al.

    Neuroenhancement among german university students: Motives, expectations, and relationship with psychoactive lifestyle drugs

    Journal of Psychoactive Drugs

    (2012)
  • C. Englert et al.

    Neuroenhancement and the strength model of self-control

    Frontiers in Psychology

    (2015)
  • R. Esposito et al.

    Acute effects of modafinil on brain resting state networks in young healthy subjects

    PLoS One

    (2013)
  • M.J. Farah et al.

    When we enhance cognition with Adderall, do we sacrifice creativity? A preliminary study

    Psychopharmacology

    (2009)
  • A.G. Franke et al.

    Non-medical use of prescription stimulants and illicit use of stimulants for cognitive enhancement in pupils and students in Germany

    Pharmacopsychiatry

    (2011)
  • A.M. Hamed et al.

    Why the diagnosis of attention deficit hyperactivity disorder matters

    Frontiers in Psychiatry

    (2015)
  • T.D. Hotze et al.

    Doctor, would you prescribe a pill to help me …? A national survey of physicians on using medicine for human enhancement

    The American Journal of Bioethics: AJOB

    (2011)
  • S. Kaye et al.

    The diversion and misuse of pharmaceutical stimulants: What do we know and why should we care?

    Addiction (Abingdon, England)

    (2012)
  • E.J. Khantzian

    The self-Medication hypothesis of substance use disorders: A reconsideration and recent applications

    Harvard Review of Psychiatry

    (1997)
  • M. Kordt

    DAK Gesundheitsreport 2009

    (2009)
  • M. Kordt

    DAK Gesundheitsreport 2015

    (2015)
  • M. Lecendreux et al.

    Prevalence of attention deficit hyperactivity disorder and associated features among children in France

    Journal of Attention Disorders

    (2011)
  • Cited by (84)

    • Pre-clinical evidence that methylphenidate increases motivation and/or reward preference to search for high value rewards

      2023, Behavioural Brain Research
      Citation Excerpt :

      Methylphenidate is a stimulant used to treat attention deficit and hyperactivity disorder (ADHD) and other psychiatric diseases. In the last decade, the illicit use of methylphenidate increased in healthy adolescents and young adults, who use it under the assumption that methylphenidate will enhance academic or work performance [40,53]. Epidemiologic studies report a range from 4.2% to 60% of students reported illicit methylphenidate use to improve their academic performance [39,53,64].

    • Vinpocetine, a PDE1 modulator, regulates markers of cerebral health, inflammation, and oxidative stress in a rat model of prenatal alcohol-induced experimental attention deficit hyperactivity disorder

      2022, Alcohol
      Citation Excerpt :

      The choice of animal species, sex, and age was based on research already published by others and our lab, effectively using rats to model experimental ADHD (Atalar et al., 2016; Hausknecht et al., 2005; Sharma, Dhiman, et al., 2021). A number of studies indicate males are more likely to be affected/diagnosed with ADHD during adolescence (Maier, Ferris, & Winstock, 2018; Moffitt et al., 2015), while females are more likely to be diagnosed in their adult lives (Biederman & Faraone, 2005; Simon, Czobor, Bálint, Mészáros, & Bitter, 2009; Thapar & Cooper, 2016). The number of preadolescent/teenage males severely outnumbers females of the same age group by 2:1 to 9:1, depending on the subtype of the diagnosis (Biederman, Faraone, Monuteaux, Bober, & Cadogen, 2004; Rucklidge, 2010).

    • Balancing consumption and constraint: Binge drinking, stimulant misuse, and relational capital among young adults

      2022, Social Science and Medicine
      Citation Excerpt :

      Moreover, as the U.S. has recently showed only modest growth in prescription stimulant use, known as a “ceiling effect” of a medications lifespan, other parts of the world, particularly Canada, the Netherlands, Denmark, and Australia have seen their prescribing of psycho-stimulant medications dramatically increase (Raman et al., 2018). These global trends reveal that differences in prescribing practices and prevalence of prescription stimulant misuse between the U.S. and the rest of the postindustrial world are shrinking (Maier et al., 2018). While medicalization scholars have raised alarms about the implications of such widespread prescribing (Conrad and Bergey, 2014), concerns among health professions regarding the increasing availability of these controlled substances tend not to be problematized in and of themselves, but only in relation to corresponding increases in their misuse.

    View all citing articles on Scopus
    View full text