[Pharmacological neuroenhancement and brain doping : Chances and risks]

Caffeine, Alcohol, and Drug Use as Work Adjuncts Among Neurosurgeons. Prevalence, Contributing Factors, and Proposed Strategies

BACKGROUND

Neurosurgeons may resort to caffeine, alcohol, and various drugs to maintain peak performance as they grapple with work demands and escalated stress. The prevalence of this controversial strategy remains largely unexplored.

METHODS

An anonymous survey of 23 questions formulated by our research group was distributed through personal contacts and neurosurgical societies. Inquiries revolved around the use of medications and other substances for job-related reasons. Data were analyzed via regression and descriptive statistics in python.

RESULTS

In total, 215 neurosurgeons (43 residents) were included, with 213 disclosing their gender (94 females). Out of all, 9.3% were <30, 38.1% were 30-39, 44.6% were 40-59, and 7.9% were >60 years old. Most (70.7%) practiced in Europe, 18.6% in Asia, 6.5% in North and South America, and the rest in Africa or Australia. While 132 participants stated they consume caffeine to manage challenging schedules, drugs for cognitive and mood enhancement were utilized by 18 and 35 respectively. Alcohol was employed for stress relief by 28 with 4 reporting as heavy drinkers. Drugs posed a solution to sleep disorders for 82, and helped 8 others in strengthening their hand dexterity. Notably, 12 of those claiming drug use initiated it in medical school. Exercise, self-care activities, and relational support were the main alternatives sought. Ultimately, most responders recommended extending mental health assistance and raising awareness about drug use.

CONCLUSIONS

Reflecting on our results on job-associated drug use by neurosurgeons, we propose the judicious use of pharmacological or nonpharmacological adjuncts, alongside the prioritization of neurosurgeons' well-being.

Cigarette Smoking, Risky Alcohol Consumption, and Marijuana Smoking among University Students in Germany: Identification of Potential Sociodemographic and Study-Related Risk Groups and Predictors of Consumption

(1) Background: Cigarette smoking, risky alcohol consumption, and marijuana smoking are the most common behaviors related to legal and illicit drug use worldwide, including among university students. To plan effective evidence-based programs to prevent the risky consumption of these substances among university students, the present study aimed to identify potential sociodemographic and study-related risk groups and predictors of consumption. (2) Methods: A cross-sectional online health survey with approximately 270 health-related items was conducted among students at the University of Mainz, Germany. Cigarette smoking, risky alcohol consumption (AUDIT-C score: female ≥ 4, male ≥ 5), and marijuana smoking were chosen as dependent variables. Of the 270 health-related items, 56 were chosen as independent variables and collated into five groups (sociodemographic, psychological, study-related psychosocial, general psychosocial and health behavior). The prevalence of cigarette smoking, risky alcohol consumption, and marijuana smoking was assessed using established and validated instruments. Pearson's chi-square test was used to analyze the differences in prevalence between the sociodemographic and study-related groups, and binary logistic regression was used for analyses with stepwise inclusion of the five variable groups. (3) Results: Of the 3991 university students who entered the analyses, 14.9% reported smoking cigarettes, 38.6% reported risky alcohol consumption, and 10.9% reported smoking marijuana. The prevalence of these differed between genders, fields of study, and aspired degree level, among other factors. Binary logistic regression analyses revealed nine significant predictors (p ≤ 0.05) of cigarette smoking (Nagelkerke R2 = 0.314), 18 significant predictors of risky alcohol consumption (Nagelkerke R2 = 0.270), and 16 significant predictors of marijuana smoking (Nagelkerke R2 = 0.239). (4) Conclusions: This study showed cigarette smoking, risky alcohol consumption, and marijuana smoking among university students in Germany to be associated with multiple factors, especially health behaviors. Furthermore, each of the substances was highly associated with each of the two other substances we examined. Other variable groups, such as psychological or psychosocial variables, seemed to play a rather minor role. Therefore, our recommendation for future prevention programs is that substance use among university students should be addressed as a whole, not just in terms of specific substances.

The relevance of pharmacological neuroenhancement for stress and resilience-A multistudy report

Background

Pharmacological neuroenhancement (PNE) is discussed as coping strategy in academic and work-related contexts. Depending on the definition of PNE and sample population, different prevalence rates for various groups have been reported. In the three parts of the study, prevalence rates for work and student populations in Germany are detected and the reasons for PNE and possible causal associations between PNE, stress and resilience are investigated.

Methods

In part 1 of the study, 152 occupational physicians (OPs) were surveyed about prevalence rates and reasons for PNE. In part 2 of the study, 1,077 German students reported on their PNE behavior. 704 students were then longitudinally considered to draw conclusions on causal associations between PNE, stress, and resilience.

Results

The OPs' estimated prevalence rate of 10.9% in a working population is higher than the prevalence rate of 5.4% for prescription and illicit substances found in the student sample in part 2 of the study. The reason suspected by OPs to be most important for PNE with prescription drugs were performance pressure and long working hours. Using soft enhancers, such as caffeine, is most common with a prevalence rate of 76.8% in the student sample. Stress predicts a higher (β = 0.179, p < 0.001) and resilience a lower use of PNE (β = -0.13, p = 0.001). Resilience predicts a lower (β = -0.35, p < 0.001) and PNE a higher level of stress (β = 0.11, p < 0.001).

Conclusion

OPs suspect a prevalence rate of 10.9% among the working population, while we found a prevalence rate of 5.4% among students. Caffeine is the most used substance for PNE, while the use of prescription and illicit substances remains low. Higher levels of stress and lower levels of resilience result in a higher use of PNE. Universities should therefore include the promotion of resilience and methods for dealing with study stress in health programs to reduce PNE.

Cognitive enhancement: Effects of methylphenidate, modafinil, and caffeine on latent memory and resting state functional connectivity in healthy adults

Stimulants like methylphenidate, modafinil, and caffeine have repeatedly shown to enhance cognitive processes such as attention and memory. However, brain-functional mechanisms underlying such cognitive enhancing effects of stimulants are still poorly characterized. Here, we utilized behavioral and resting-state fMRI data from a double-blind randomized placebocontrolled study of methylphenidate, modafinil, and caffeine in 48 healthy male adults. The results show that performance in different memory tasks is enhanced, and functional connectivity (FC) specifically between the frontoparietal network (FPN) and default mode network (DMN) is modulated by the stimulants in comparison to placebo. Decreased negative connectivity between right prefrontal and medial parietal but also between medial temporal lobe and visual brain regions predicted stimulant-induced latent memory enhancement. We discuss dopamine's role in attention and memory as well as its ability to modulate FC between large-scale neural networks (e.g., FPN and DMN) as a potential cognitive enhancement mechanism.

The Prevalence of Pharmacological Neuroenhancement Among University Students Before and During the COVID-19-Pandemic: Results of Three Consecutive Cross-Sectional Survey Studies in Germany

Background

According to the literature, the conditions of studying and living as well as the psychological, social and health behavior-related variables, which were strongly related to pharmacological neuroenhancement (PN) before the pandemic, significantly changed during the pandemic. For this reason, it is expected that the prevalence of PN among university students is higher during the pandemic compared to before the pandemic. Therefore, the present study aimed to investigate and compare the prevalence of PN among university students before and during the COVID-19-pandemic.

Methods

Three online surveys assessing the 12-month prevalence of PN were conducted among university students at the University of Mainz, Germany. The first survey took place in summer term 2019 (before the pandemic), the second in summer term 2020 (during the first German lockdown), and the third in summer term 2021 (after the second German lockdown). Pearson's chi-square test was used to test whether the 12-month prevalence of PN differed significantly between the three surveys.

Results

The 12-month prevalence of PN was 10.4% in 2019, 11.3% in 2020, and 8.0% in 2021. Chi-square tests revealed no statistical difference in the prevalence of PN between 2019 and 2020. Overall, the use of PN was lower in 2021 compared to 2019 (p < 0.0001) as well as in comparison to 2020 (p = 0.001). Only the use of cannabis slightly increased from 2019 to 2020 (7.1 vs. 8.3%) and decreased in 2021 (5.4%). At all three time points, cannabis was the most commonly used substance for the purpose of PN. Consequently, the results suggest that the prevalence of PN was highly intertwined with the prevalence of cannabis use for PN.

Discussion

The decrease in the prevalence of PN of around three percentage points in 2021 compared to the previous years was a surprising finding. It may be mainly due to the decrease in the prevalence of cannabis for the purpose of PN. However, the fairly high prevalence of PN of around 8% in 2021 is still an important finding that demonstrates that there is still an urgent need for prevention initiatives among university students to combat the use of PN.

Potential risk groups and psychological, psychosocial, and health behavioral predictors of pharmacological neuroenhancement among university students in Germany

Aiming to develop and implement intervention strategies targeting pharmacological neuroenhancement (PN) among university students more specifically, we (1) assessed the prevalence of PN among German university students, (2) identified potential sociodemographic and study-related risk groups, and (3) investigated sociodemographic, psychological, study-related psychosocial, general psychosocial and health behavior related factors predicting the 12-month prevalence of PN. Therefore, a cross-sectional online survey was administered to students of the University of Mainz, Germany. A binary logistic regression with stepwise inclusion of the five variable groups was performed to predict PN. A total number of 4351 students out of 31,213 registered students (13.9%) participated in the survey, of which N = 3984 answered the question concerning PN. Of these, 10.4% had used one substance for PN at least once in the past 12 months. The regression analysis revealed 13 variables that were significantly related to the 12-month prevalence of PN. Specifically, the group of health behavior related variables showed the strongest relationship with PN. Therefore, an approach to the prevention of PN should be multifactorial so that it addresses social conditions, as well as education on substance use and healthy behaviors in terms of non-pharmacological strategies as alternatives of PN.

Just "Like Coffee" or Neuroenhancement by Stimulants?

Introduction: Pharmacological neuroenhancement (PN) is a topic of increasing importance and prevalence among students. However, there is a lack of differentiating PN substances, according to their psychoactive effects. In particular, there is a lack of data about PN by caffeinated drinks, even if coffee is a common and broadly used Neuroenhancer because of its cognitively enhancing effects regarding wakefulness, alertness and concentration.

Materials and Methods: A web-survey was developed for German students and alumni about the non-medical use of caffeine for PN contained questions about coffee, caffeinated drinks and energy drinks, caffeine pills and methylxanthine tea regarding frequency and further contextual factors.

Results: Six hundred and eighty-three participants completed the survey. Nearly all participants knew about PN (97.7%). 88.1% admitted using some over-the-counter substances. For PN purposes, coffee was used by 72.9% followed by energy drinks (68.2%) and cola drinks (62.4%). Methylxanthine containing tea was used for PN purposes, too (black tea 52.3%, green tea 51.7%). 1.8% admitted using illegal substances or prescription drugs, too.

Discussion: Using legal methylxanthine containing drinks for PN seems to be extremely common with coffee and energy drinks being the preferred substances, while illegal and prescription drugs are only minimally used. Further studies should investigate the awareness of methylxanthine containing drinks as well as its character to be a flavoring drink or a neuroenhancer.

Pharmacological Neuroenhancement: Current Aspects of Categorization, Epidemiology, Pharmacology, Drug Development, Ethics, and Future Perspectives

Recent pharmacoepidemiologic studies suggest that pharmacological neuroenhancement (pNE) and mood enhancement are globally expanding phenomena with distinctly different regional characteristics. Sociocultural and regulatory aspects, as well as health policies, play a central role in addition to medical care and prescription practices. The users mainly display self-involved motivations related to cognitive enhancement, emotional stability, and adaptivity. Natural stimulants, as well as drugs, represent substance abuse groups. The latter comprise purines, methylxanthines, phenylethylamines, modafinil, nootropics, antidepressants but also benzodiazepines, β-adrenoceptor antagonists, and cannabis. Predominant pharmacodynamic target structures of these substances are the noradrenergic/dopaminergic and cholinergic receptor/transporter systems. Further targets comprise adenosine, serotonin, and glutamate receptors. Meta-analyses of randomized-controlled studies in healthy individuals show no or very limited verifiability of positive effects of pNE on attention, vigilance, learning, and memory. Only some members of the substance abuse groups, i.e., phenylethylamines and modafinil, display positive effects on attention and vigilance that are comparable to caffeinated drinks. However, the development of new antidementia drugs will increase the availability and the potential abuse of pNE. Social education, restrictive regulatory measures, and consistent medical prescription practices are essential to restrict the phenomenon of neuroenhancement with its social, medical, and ethical implications. This review provides a comprehensive overview of the highly dynamic field of pharmacological neuroenhancement and elaborates the dramatic challenges for the medical, sociocultural, and ethical fundaments of society.

Protective Effects of the Caffeine Against Neurodegenerative Diseases

Background:

Recent studies and increased interest of the scientific community helped to clarify the neurological health property of caffeine, one of the pharmacologically active substances most consumed in the world.

Methods:

This article is a review search to provide an overview on the current state of understanding neurobiochemical impact of caffeine, focusing on the ability of the drug to effectively counteract several neurodegenerative disorders such as Alzheimer’s, Parkinson’s, Huntington’s diseases, Multiple sclerosis and Amyotrophic lateral sclerosis.

Results:

Data collection shown in this review provide a significant therapeutic and prophylactic potentiality of caffeine which acts on human brain through several pathways because of its antioxidant activity combined with multiple molecular targets. However, the need to adjust the CF dosage to individuals, because some people are more sensitive to drugs than others, may constituted a limit to the CF effectiveness.

Conclusion:

What emerges from the complex of clinical and epidemiological studies is a significant CF potential impact against all neurological disorders. Although, further studies are needed to fully elucidate the several mechanisms of drug action which in part are still elusive.

Prevalence Estimates for Pharmacological Neuroenhancement in Austrian University Students: Its Relation to Health-Related Risk Attitude and the Framing Effect of Caffeine Tablets

Background: Pharmacological neuroenhancement (PN) is defined as the use of illicit or prescription drugs by healthy individuals for cognitive-enhancing purposes. The present study aimed (i) to investigate whether including caffeine tablets in the definition of PN within a questionnaire increases the PN prevalence estimate (framing effect), (ii) to investigate whether the health-related risk attitude is increased in students who use PN. Materials and methods: Two versions of a paper-and-pencil questionnaire (first version included caffeine tablets in the definition of PN, the second excluded caffeine tablets) were distributed among university students at the University of Graz, Austria. The unrelated question model (UQM) was used to estimate the 12-month PN prevalence and the German version of the 30-item Domain-Specific Risk-Taking (DOSPERT) scale to assess the health-related risk attitude. Moreover, large-sample z-tests (α = 0.05) were performed for comparing the PN prevalence estimates of two groups. Results: Two thousand four hundred and eighty-nine questionnaires were distributed and 2,284 (91.8%) questionnaires were included in analysis. The overall PN prevalence estimate for all students was 11.9%. One-tailed large-sample z-tests revealed that the PN estimate for students with higher health-related risk attitude was significantly higher compared to students with lower health-related risk attitude (15.6 vs. 8.5%; z = 2.65, p = 0.004). Furthermore, when caffeine tablets were included into the example of PN, the prevalence estimate of PN was significantly higher compared to the version without caffeine tablets (14.9 vs. 9.0%; z = 2.20, p = 0.014). Discussion: This study revealed that the PN prevalence estimate increases when caffeine tablets are included in the definition of PN. Therefore, future studies investigating the prevalence of, and predictors for, PN should be performed and interpreted with respect to potential framing effects. This study further revealed that the PN prevalence estimate is increased in students with a higher health-related risk attitude compared to students with a lower one. Therefore, future education and prevention programs addressing PN in the collective of students should not only inform about potential side effects of its use but also address the limited effects on cognition and potential alternatives of PN.

Acute effects of lisdexamfetamine and D-amphetamine on social cognition and cognitive performance in a placebo-controlled study in healthy subjects

RATIONALE

Amphetamines are used as medications but are also misused as cognitive enhancers by healthy subjects and may have additional effects on social cognition.

METHODS

We investigated the acute effects of single, high, equimolar doses of D-amphetamine (40 mg) and lisdexamfetamine (100 mg) on social cognition and cognitive performance using a randomized, placebo-controlled, double-blind, cross-over design in 24 healthy volunteers. Effects on social cognition were assessed using the Facial Emotion Recognition Task (FERT), Multifaceted Empathy Test (MET), and Sexual Arousal Task (SAT). Cognitive performance was measured using the Digit Symbol Substitution Test (DSST), Digit Span (DS), Stop-Signal Task (SST), and Mackworth Clock Test (MCT).

RESULTS

D-Amphetamine and lisdexamfetamine had small effects on measures of social cognition. There were no effects on emotion recognition on the FERT. D-Amphetamine increased direct empathy on the MET, but only for positive stimuli. Both amphetamines increased ratings of pleasantness and attractiveness on the SAT in response to sexual but also to neutral stimuli. D-Amphetamine and lisdexamfetamine increased cognitive performance (go-accuracy and vigilance on the SST and MCT, respectively). Lisdexamfetamine increased processing speed on the DSST. Neither drug had an effect on the DS.

CONCLUSION

Single, high, equimolar doses of D-amphetamine and lisdexamfetamine enhanced certain aspects of cognitive performance in healthy non-sleep-deprived subjects. Both amphetamines also slightly altered aspects of social cognition. Whether these small effects also influence social interaction behavior in amphetamine users remains to be investigated.

TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov (NCT02668926).

[Doping for the brain]

The enhancement of physical and cognitive abilities (i. e. concentration, vigilance, memory) has always been desirable for humans. The term pharmacological neuroenhancement refers to the use of legal or nonprescription psychoactive substances by healthy subjects with the intention of cognitive enhancement. To give the most prominent example, caffeine serves worldwide as a natural stimulant. Brain doping, however, specifies the use of illegal substances or prescription drugs beyond approval with the purpose of cognitive enhancement. Only amphetamines, methylphenidate and modafinil have significant effects on attentiveness, concentration and alertness, whereas other substances, such as anti-dementia drugs or anti-depressants failed to demonstrate cognitive enhancement in healthy subjects.

Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines

Low intensity transcranial electrical stimulation (TES) in humans, encompassing transcranial direct current (tDCS), transcutaneous spinal Direct Current Stimulation (tsDCS), transcranial alternating current (tACS), and transcranial random noise (tRNS) stimulation or their combinations, appears to be safe. No serious adverse events (SAEs) have been reported so far in over 18,000 sessions administered to healthy subjects, neurological and psychiatric patients, as summarized here. Moderate adverse events (AEs), as defined by the necessity to intervene, are rare, and include skin burns with tDCS due to suboptimal electrode-skin contact. Very rarely mania or hypomania was induced in patients with depression (11 documented cases), yet a causal relationship is difficult to prove because of the low incidence rate and limited numbers of subjects in controlled trials. Mild AEs (MAEs) include headache and fatigue following stimulation as well as prickling and burning sensations occurring during tDCS at peak-to-baseline intensities of 1-2mA and during tACS at higher peak-to-peak intensities above 2mA. The prevalence of published AEs is different in studies specifically assessing AEs vs. those not assessing them, being higher in the former. AEs are frequently reported by individuals receiving placebo stimulation. The profile of AEs in terms of frequency, magnitude and type is comparable in healthy and clinical populations, and this is also the case for more vulnerable populations, such as children, elderly persons, or pregnant women. Combined interventions (e.g., co-application of drugs, electrophysiological measurements, neuroimaging) were not associated with further safety issues. Safety is established for low-intensity 'conventional' TES defined as <4mA, up to 60min duration per day. Animal studies and modeling evidence indicate that brain injury could occur at predicted current densities in the brain of 6.3-13A/m2 that are over an order of magnitude above those produced by tDCS in humans. Using AC stimulation fewer AEs were reported compared to DC. In specific paradigms with amplitudes of up to 10mA, frequencies in the kHz range appear to be safe. In this paper we provide structured interviews and recommend their use in future controlled studies, in particular when trying to extend the parameters applied. We also discuss recent regulatory issues, reporting practices and ethical issues. These recommendations achieved consensus in a meeting, which took place in Göttingen, Germany, on September 6-7, 2016 and were refined thereafter by email correspondence.

Use of cognitive enhancers among medical students in Lithuania

Aims

The purpose of this study is to analyse the use of cognitive enhancers among medical students in Lithuania, determine the reasons for usage and evaluate the contributing factors such as socio-demographic characteristics, stress levels, sleep quality and knowing somebody who has used a neuro-enhancing drug.

Design

A cross-sectional survey study was performed by analysing a convenience sample of n=579 in the two universities offering medical education in Lithuania, Vilnius University and the Lithuanian University of Health Sciences. In 2014, students were asked to fill in anonymous paper questionnaires consisting of 13 items on prevalence of substance use to enhance cognitive performance, and on reasons and correlates (response rate 95%) during lecture time.

Results

Of the respondents, 8.1% indicated that they had used cognitive enhancers. Among those who had used these drugs, nootropics were the most frequently mentioned (59.6%), while psychostimulants, such as modafinil, methylphenidate and amphetamine-derived drugs were mentioned less frequently (38.3%). Other substances were indicated by 23.4% of the respondents. Improvement of concentration and increased studying time were predominant purposes (55.3% and 48.9% of users, respectively). Male students reported three times higher prevalence rates than females (14.6% vs. 5.1%, p<0.05). Prevalence was also higher in students who knew someone using these substances than among those who did not know such persons (17.3% vs. 5.1%, p< 0.05). This was the most associated factor with cognitive-enhancing drug-taking behaviour. No correlation between cognitive enhancement usage and sleep quality or stress levels was found, nor between usage and belonging to a student organisation or having a job.

Conclusions

In Lithuania, 1 of 12 medical students admits to having used neuro-enhancing drugs. Our study results provide an overview of the actual situation on correlates and reasons for taking performance-enhancing substances.

Using Caffeine Pills for Performance Enhancement. An Experimental Study on University Students' Willingness and Their Intention to Try Neuroenhancements

Recent research has indicated that university students sometimes use caffeine pills for neuroenhancement (NE; non-medical use of psychoactive substances or technology to produce a subjective enhancement in psychological functioning and experience), especially during exam preparation. In our factorial survey experiment, we manipulated the evidence participants were given about the prevalence of NE amongst peers and measured the resulting effects on the psychological predictors included in the Prototype-Willingness Model of risk behavior. Two hundred and thirty-one university students were randomized to a high prevalence condition (read faked research results overstating usage of caffeine pills amongst peers by a factor of 5; 50%), low prevalence condition (half the estimated prevalence; 5%) or control condition (no information about peer prevalence). Structural equation modeling confirmed that our participants’ willingness and intention to use caffeine pills in the next exam period could be explained by their past use of neuroenhancers, attitude to NE and subjective norm about use of caffeine pills whilst image of the typical user was a much less important factor. Provision of inaccurate information about prevalence reduced the predictive power of attitude with respect to willingness by 40-45%. This may be because receiving information about peer prevalence which does not fit with their perception of the social norm causes people to question their attitude. Prevalence information might exert a deterrent effect on NE via the attitude-willingness association. We argue that research into NE and deterrence of associated risk behaviors should be informed by psychological theory.

The Use of Prescription Drugs, Recreational Drugs, and "Soft Enhancers" for Cognitive Enhancement among Swiss Secondary School Students

The use of prescription or recreational drugs for cognitive enhancement (CE) is prevalent among students. However, the prevalence of CE among Swiss school students is unknown. We therefore performed a cross-sectional online survey including ≥ 16-year-old students from bridge-year schools (10^th grade), vocational schools, and upper secondary schools (10^th-12^th grade) in the Canton of Zurich to investigate the prevalence of and motives for the use of prescription drugs, recreational drugs, and/or freely available soft enhancers for CE. A total of 1,139 students were included. Of these, 54.5% reported the use of prescription drugs (9.2%), recreational drugs including alcohol (6.2%), or soft enhancers (51.3%) explicitly for CE at least once in their lives. The last-year and last-month prevalence for CE considering all substances was 45.5% and 39.5%, respectively. Soft enhancers were the substances that were most commonly used (ever, last-year, and last-month, respectively), including energy drinks (33.3%, 28.4%, and 24.6%), coffee (29.8%, 25.1%, and 21.9%), and tobacco (12.6%, 9.3%, and 8.3%). CE with methylphenidate was less prevalent (4.0%, 2.8%, and 2.0%). However, the use of prescription drugs, alcohol, or illegal drugs for CE was reported by 13.3% of the participants. The most common motives for use were to stay awake and improve concentration. CE was more prevalent among students who reported higher levels of stress or performance pressure and students with psychiatric disorders. In conclusion, half of the school students had used a substance at least once in their lives to improve school performance. Soft enhancers were most commonly used. Prevalence rates were similar to those reported by Swiss university students, indicating that the use of prescription or recreational drugs for CE already occurs before starting higher education. Performance pressure, stress, and psychiatric disorders may be associated with CE.

The Use of Prescription Drugs and Drugs of Abuse for Neuroenhancement in Europe

Abstract. Pharmacological neuroenhancement, defined as the misuse of prescription drugs, illicit drugs, or alcohol for the purpose of enhancing cognition, mood, or prosocial behavior, is not widespread in Europe – nevertheless, it does occur. Thus far, no drug has been proven as safe and effective for cognitive enhancement in otherwise healthy individuals. European studies have investigated the misuse of prescription and illicit stimulants to increase cognitive performance as well as the use of tranquilizers, alcohol, and cannabis to cope with stress related to work or education. Young people in educational settings report pharmacological neuroenhancement more frequently than those in other settings. Although the regular use of drugs for neuroenhancement is not common in Europe, the irregular and low-dose usage of neuroenhancers might cause adverse reactions. Previous studies have revealed that obtaining adequate amounts of sleep and using successful learning techniques effectively improve mental performance, whereas pharmacological neuroenhancement is associated with ambiguous effects. Therefore, non-substance-related alternatives should be promoted to cope with stressful situations. This paper reviews the recent research on pharmacological neuroenhancement in Europe, develops a clear definition of the substances used, and formulates recommendations for practitioners regarding how to react to requests for neuroenhancement drug prescriptions. We conclude that monitoring the future development of pharmacological neuroenhancement in Europe is important to provide effective preventive measures when required. Furthermore, substance use to cope with stress related to work or education should be studied in depth because it is likely more prevalent and dangerous than direct neuroenhancement.

Substances used and prevalence rates of pharmacological cognitive enhancement among healthy subjects

Pharmacological "cognitive enhancement" (CE) is defined as the use of any psychoactive drug with the purpose of enhancing cognition, e.g. regarding attention, concentration or memory by healthy subjects. Substances commonly used as CE drugs can be categorized into three groups of drugs: (1) over-the-counter (OTC) drugs such as coffee, caffeinated drinks/energy drinks, caffeine tablets or Ginkgo biloba; (2) drugs being approved for the treatment of certain disorders and being misused for CE: drugs to treat attention-deficit/hyperactivity disorder (ADHD) such as the stimulants methylphenidate (MPH, e.g. Ritalin(®)) or amphetamines (AMPH, e.g. Attentin(®) or Adderall(®)), to treat sleep disorders such as modafinil or to treat Alzheimer's disease such as acetylcholinesterase inhibitors; (3) illicit drugs such as illicit AMPH, e.g. "speed", ecstasy, methamphetamine (crystal meth) or others. Evidence from randomized placebo-controlled trials shows that the abovementioned substances have limited pro-cognitive effects as demonstrated, e.g. regarding increased attention, increased cognitive speed or shortening of reaction times, but on the same time poses considerable safety risks on the consumers. Prevalence rates for the use of CE drugs among healthy subjects show a broad range from less than 1 % up to more than 20 %. The range in prevalence rates estimates results from several factors which are chosen differently in the available survey studies: type of subjects (students, pupils, special professions, etc.), degree of anonymity in the survey (online, face-to-face, etc.), definition of CE and substances used/misused for CE, which are assessed (OTC drugs, prescription, illicit drugs) as well as time periods of use (e.g. ever, during the past year/month/week, etc.). A clear and comprehensive picture of the drugs used for CE by healthy subjects and their adverse events and safety risks as well as comprehensive and comparable international data on the prevalence rates of CE among healthy subjects are of paramount importance for informing policy makers and healthcare professionals about CE.

The use of Ginkgo biloba in healthy elderly

To promote health-conscious behavior in the aging society and gain insight into the sources of knowledge on which preventive strategies are based, analyzing the behavior of elderly people who are recognized as highly health conscious may be useful. We focused on the use of Ginkgo biloba, which is commonly considered to be effective in preventing cognitive decline and dementia, among elderly adults. A total of 1,672 questionnaires were distributed among geriatric participants (60-94 years) who attended university lectures at 22 universities throughout Germany. Response rate was 36.1 %. We collected data on demographic characteristics, preventive strategies (use of Ginkgo and other supplements), health-conscious behavior, sources of knowledge concerning health behavior, and factors associated with the participants' concept of aging. The prevalence of Ginkgo use was 15.3 %. Ginkgo was assumed to be effective for cognitive enhancement and the treatment of cognitive decline by two thirds of the surveyed participants and one third believed Ginkgo to be effective for preventing dementia. Ginkgo use was significantly higher among participants using natural remedies and herbal and food supplements. The use of Ginkgo was recommended by physicians (57.3 %), chemists (16 %), and healthcare magazines (10.7 %). Food supplements were taken by 65.8 % of the sample: this percentage was significantly higher among subjects who exhibited health-conscious behavior. "Knowledge" about strategies to enhance cognition or prevent cognitive decline among the elderly do not appear to be evidence based. Thus, there is a need to establish reliable and independent sources of scientific information for healthcare professionals and the general public.

Evaluating the drivers of and obstacles to the willingness to use cognitive enhancement drugs: the influence of drug characteristics, social environment, and personal characteristics

BACKGROUND

The use of cognitive enhancement (CE) by means of pharmaceutical agents has been the subject of intense debate both among scientists and in the media. This study investigates several drivers of and obstacles to the willingness to use prescription drugs non-medically for augmenting brain capacity.

METHODS

We conducted a web-based study among 2,877 students from randomly selected disciplines at German universities. Using a factorial survey, respondents expressed their willingness to take various hypothetical CE-drugs; the drugs were described by five experimentally varied characteristics and the social environment by three varied characteristics. Personal characteristics and demographic controls were also measured.

RESULTS

We found that 65.3% of the respondents staunchly refused to use CE-drugs. The results of a multivariate negative binomial regression indicated that respondents' willingness to use CE-drugs increased if the potential drugs promised a significant augmentation of mental capacity and a high probability of achieving this augmentation. Willingness decreased when there was a high probability of side effects and a high price. Prevalent CE-drug use among peers increased willingness, whereas a social environment that strongly disapproved of these drugs decreased it. Regarding the respondents' characteristics, pronounced academic procrastination, high cognitive test anxiety, low intrinsic motivation, low internalization of social norms against CE-drug use, and past experiences with CE-drugs increased willingness. The potential severity of side effects, social recommendations about using CE-drugs, risk preferences, and competencies had no measured effects upon willingness.

CONCLUSIONS

These findings contribute to understanding factors that influence the willingness to use CE-drugs. They support the assumption of instrumental drug use and may contribute to the development of prevention, policy, and educational strategies.

Attitudes towards prescribing cognitive enhancers among primary care physicians in Germany

BACKGROUND

Primary care physicians are gate keepers to the medical system having a key role in giving information and prescribing drugs to their patients. In this respect they are involved in claims of patients/clients for pharmacological Cognitive Enhancement (CE). Therefore, we studied the knowledge of primary care physicians about CE and their attitudes toward prescribing CE drugs to healthy subjects.

METHODS

A self-report paper-and-pencil questionnaire and case vignettes describing a hypothetical CE drug were sent out to all 2,753 registered primary care physicians in Rhineland Palatine, Germany. 832, i.e. 30.2% filled in the questionnaire anonymously.

RESULTS

96.0% of all participating physicians had already heard about CE. However, only 5.3% stated to be very familiar with this subject and 43.5% judged themselves as being not familiar with CE. 7.0% had been asked by their clients to prescribe a drug for CE during the last week, 19.0% during the last month, and 40.8% during the last year. The comfort level to prescribe CE drugs was very low and significantly lower than to prescribe sildenafil (Viagra®). Comfort level was mainly affected by the age of the client asking for prescription of CE drugs, followed by the availability of non-pharmacological alternatives, fear of misuse of the prescribed drug by the client and the missing indication of prescribing a drug.

CONCLUSIONS

Although a relatively high proportion of primary care physicians have been asked by their clients to prescribe CE drugs, only a small proportion are well informed about the possibilities of CE. Since physicians are gate keepers to the medical system and have a key role regarding a drugs' prescription, objective information should be made available to physicians about biological, ethical and social consequences of CE use.

Associations between physical and cognitive doping--a cross-sectional study in 2.997 triathletes

Purpose

This study assessed, for the first time, prevalence estimates for physical and cognitive doping within a single collective of athletes using the randomized response technique (RRT). Furthermore, associations between the use of legal and freely available substances to improve physical and cognitive performance (enhancement) and illicit or banned substances to improve physical and cognitive performance (doping) were examined.

Methods

An anonymous questionnaire using the unrelated question RRT was used to survey 2,997 recreational triathletes in three sports events (Frankfurt, Regensburg, and Wiesbaden) in Germany. Prior to the survey, statistical power analyses were performed to determine sample size. Logistic regression was used to predict physical and cognitive enhancement and the bootstrap method was used to evaluate differences between the estimated prevalences of physical and cognitive doping.

Results

2,987 questionnaires were returned (99.7%). 12-month prevalences for physical and cognitive doping were 13.0% and 15.1%, respectively. The prevalence estimate for physical doping was significantly higher in athletes who also used physical enhancers, as well as in athletes who took part in the European Championship in Frankfurt compared to those who did not. The prevalence estimate for cognitive doping was significantly higher in athletes who also used physical and cognitive enhancers. Moreover, the use of physical and cognitive enhancers were significantly associated and also the use of physical and cognitive doping.

Discussion

The use of substances to improve physical and cognitive performance was associated on both levels of legality (enhancement vs. doping) suggesting that athletes do not use substances for a specific goal but may have a general propensity to enhance. This finding is important for understanding why people use such substances. Consequently, more effective prevention programs against substance abuse and doping could be developed.

To dope or not to dope: neuroenhancement with prescription drugs and drugs of abuse among Swiss university students

Background

Neuroenhancement is the use of substances by healthy subjects to enhance mood or cognitive function. The prevalence of neuroenhancement among Swiss university students is unknown. Investigating the prevalence of neuroenhancement among students is important to monitor problematic use and evaluate the necessity of prevention programs.

Study aim

To describe the prevalence of the use of prescription medications and drugs of abuse for neuroenhancement among Swiss university students.

Method

In this cross-sectional study, students at the University of Zurich, University of Basel, and Swiss Federal Institute of Technology Zurich were invited via e-mail to participate in an online survey.

Results

A total of 28,118 students were contacted, and 6,275 students completed the survey. Across all of the institutions, 13.8% of the respondents indicated that they had used prescription drugs (7.6%) or drugs of abuse including alcohol (7.8%) at least once specifically for neuroenhancement. The most frequently used prescription drugs for neuroenhancement were methylphenidate (4.1%), sedatives (2.7%), and beta-blockers (1.2%). Alcohol was used for this purpose by 5.6% of the participants, followed by cannabis (2.5%), amphetamines (0.4%), and cocaine (0.2%). Arguments for neuroenhancement included increased learning (66.2%), relaxation or sleep improvement (51.2%), reduced nervousness (39.1%), coping with performance pressure (34.9%), increased performance (32.2%), and experimentation (20%). Neuroenhancement was significantly more prevalent among more senior students, students who reported higher levels of stress, and students who had previously used illicit drugs. Although “soft enhancers”, including coffee, energy drinks, vitamins, and tonics, were used daily in the month prior to an exam, prescription drugs or drugs of abuse were used much less frequently.

Conclusions

A significant proportion of Swiss university students across most academic disciplines reported neuroenhancement with prescription drugs and drugs of abuse. However, these substances are rarely used on a daily basis and more sporadically used prior to exams.

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

STUDY OBJECTIVE

To estimate the 12-month prevalence of cognitive-enhancing drug use.

DESIGN

Paper-and-pencil questionnaire that used the randomized response technique.

SETTING

University in Mainz, Germany.

PARTICIPANTS

A total of 2569 university students who completed the questionnaire.

MEASUREMENTS AND MAIN RESULTS

An anonymous, specialized questionnaire that used the randomized response technique was distributed to students at the beginning of classes and was collected afterward. From the responses, we calculated the prevalence of students taking drugs only to improve their cognitive performance and not to treat underlying mental disorders such as attention-deficit-hyperactivity disorder, depression, and sleep disorders. The estimated 12-month prevalence of using cognitive-enhancing drugs was 20%. Prevalence varied by sex (male 23.7%, female 17.0%), field of study (highest in students studying sports-related fields, 25.4%), and semester (first semester 24.3%, beyond first semester 16.7%). To our knowledge, this is the first time that the randomized response technique has been used to survey students about cognitive-enhancing drug use.

CONCLUSION

Using the randomized response technique, our questionnaire provided data that showed a high 12-month prevalence of cognitive-enhancing drug use in German university students. Our study suggests that other direct survey techniques have underestimated the use of these drugs. Drug prevention programs need to be established at universities to address this issue.

No evidence for effects of a high-frequency repetitive transcranial magnetic stimulation series on verbal and figural fluency and TAP task performance in healthy male volunteers

BACKGROUND

Study results on cognitive effects of repetitive transcranial magnetic stimulation (rTMS) in healthy people are inconsistent. Moreover, former trials performed exclusively single-session stimulations. This sham-controlled study analyzed the influence of 9 serial high-frequency rTMS on cognition.

METHODS

44 young healthy male volunteers received active or sham rTMS. We evaluated verbal fluency tasks, the Ruff Figural Fluency Test and different Test for Attentional Performance tasks (alertness, go/no-go, divided attention, working memory, flexibility) prior to the first stimulation, immediately (within 5-30 min) after stimulation on day 5 and on day 10 (1 day after the last stimulation).

RESULTS

Overall, our statistical analyses revealed no significant cognitive effects of serial rTMS.

CONCLUSION

In this sham-controlled study design, 9 serial rTMS over the left dorsolateral prefrontal cortex (targeted by the 5-cm rule) did neither enhance nor impair the assessed cognitive functions in healthy male volunteers.

Use of illicit and prescription drugs for cognitive or mood enhancement among surgeons

BACKGROUND

Surgeons are usually exposed to high workloads leading to fatigue and stress. This not only increases the likelihood of mistakes during surgery but also puts pressure on surgeons to use drugs to counteract fatigue, distress, concentration deficits, burnout or symptoms of depression. The prevalence of surgeons taking pharmacological cognitive enhancement (CE) or mood enhancement (ME) drugs has not been systematically assessed so far.

METHODS

Surgeons who attended five international conferences in 2011 were surveyed with an anonymous self-report questionnaire (AQ) regarding the use of prescription or illicit drugs for CE and ME and factors associated with their use. The Randomized Response Technique (RRT) was used in addition. The RRT guarantees a high degree of anonymity and confidentiality when a person is asked about stigmatizing issues, such as drug abuse.

RESULTS

A total of 3,306 questionnaires were distributed and 1,145 entered statistical analysis (response rate: 36.4%). According to the AQ, 8.9% of all surveyed surgeons confessed to having used a prescription or illicit drug exclusively for CE at least once during lifetime. As one would expect, the prevalence rate assessed by RRT was approximately 2.5-fold higher than that of the AQ (19.9%; 95% confidence interval (CI), 15.9% to 23.9%, N = 1,105). An even larger discrepancy between the RRT and AQ was observed for the use of antidepressants with a 6-fold higher prevalence (15.1%; 95% CI, 11.3% to 19.0%, N = 1,099) as compared to 2.4% with the AQ. Finally, logistic regression analysis revealed that pressure to perform at work (odds ratio (OR): 1.290; 95% CI, 1.000 to 1.666; P = 0.05) or in private life (OR: 1.266; 95% CI, 1.038 to 1.543; P = 0.02), and gross income (OR: 1.337; 95% CI, 1.091 to 1.640; P = 0.005), were positively associated with the use of drugs for CE or ME.

CONCLUSIONS

The use of illicit and prescription drugs for CE or ME is an underestimated phenomenon among surgeons which is generally attributable to high workload, perceived workload, and private stress. Such intake of drugs is associated with attempts to counteract fatigue and loss of concentration. However, drug use for CE may lead to addiction and to overestimation of one's own capabilities, which can put patients at risk. Coping strategies should be taught during medical education.

What users think about the differences between caffeine and illicit/prescription stimulants for cognitive enhancement

Pharmacological cognitive enhancement (CE) is a topic of increasing public awareness. In the scientific literature on student use of CE as a study aid for academic performance enhancement, there are high prevalence rates regarding the use of caffeinated substances (coffee, caffeinated drinks, caffeine tablets) but remarkably lower prevalence rates regarding the use of illicit/prescription stimulants such as amphetamines or methylphenidate. While the literature considers the reasons and mechanisms for these different prevalence rates from a theoretical standpoint, it lacks empirical data to account for healthy students who use both, caffeine and illicit/prescription stimulants, exclusively for the purpose of CE. Therefore, we extensively interviewed a sample of 18 healthy university students reporting non-medical use of caffeine as well as illicit/prescription stimulants for the purpose of CE in a face-to-face setting about their opinions regarding differences in general and morally-relevant differences between caffeine and stimulant use for CE. 44% of all participants answered that there is a general difference between the use of caffeine and illicit/prescription stimulants for CE, 28% did not differentiate, 28% could not decide. Furthermore, 39% stated that there is a moral difference, 56% answered that there is no moral difference and one participant was not able to comment on moral aspects. Participants came to their judgements by applying three dimensions: medical, ethical and legal. Weighing the medical, ethical and legal aspects corresponded to the students' individual preferences of substances used for CE. However, their views only partly depicted evidence-based medical aspects and the ethical issues involved. This result shows the need for well-directed and differentiated information to prevent the potentially harmful use of illicit or prescription stimulants for CE.