The Use and Impact of Cognitive Enhancers among University Students: A Systematic Review

Brain dysfunctions and neurotoxicity induced by psychostimulants in experimental models and humans: an overview of recent findings

Preclinical and clinical studies indicate that psychostimulants, in addition to having abuse potential, may elicit brain dysfunctions and/or neurotoxic effects. Central toxicity induced by psychostimulants may pose serious health risks since the recreational use of these substances is on the rise among young people and adults. The present review provides an overview of recent research, conducted between 2018 and 2023, focusing on brain dysfunctions and neurotoxic effects elicited in experimental models and humans by amphetamine, cocaine, methamphetamine, 3,4-methylenedioxymethamphetamine, methylphenidate, caffeine, and nicotine. Detailed elucidation of factors and mechanisms that underlie psychostimulant-induced brain dysfunction and neurotoxicity is crucial for understanding the acute and enduring noxious brain effects that may occur in individuals who use psychostimulants for recreational and/or therapeutic purposes.

Effects of methylphenidate on mitochondrial dynamics and bioenergetics in the prefrontal cortex of juvenile rats are sex-dependent

Methylphenidate (MPH) is a central nervous system stimulant drug and a first order prescription in the treatment of Attention Deficit Hyperactivity Disorder (ADHD). Although MPH biochemistry in neurodevelopment is not completely understood, studies showed it alters energy metabolism in rat brains. ADHD prevalence during neurodevelopment is related to males and the investigation has been mainly done in these subjects, therefore, little is known about MPH action in females and, consequently, about sexual dimorphism. In the present study we evaluated markers of mitochondrial dynamics (DRP1 and MFN2, fission and fusion, respectively), biogenesis (mtTFA) and bioenergetics (respiratory chain complexes) in prefrontal cortex of male and female juvenile rats submitted to exposure to MPH to better understand MPH effect during postnatal neurodevelopment. ATP and oxidative stress levels were also evaluated. Wistar rats received intraperitoneal injection of MPH (2.0 mg/kg) or control (saline), once a day, from 15th to 45th day of age. Results showed that MPH increased DRP1 and decreased MFN2, as well as increased mtTFA in prefrontal cortex of male rats. In female, MPH decreased NRF1 and increased Parkin, which are mitochondrial regulatory proteins. Respiratory chain complexes (complex I, SDH, complexes III and IV), ATP production and oxidative stress parameters were altered and shown to be sex-dependent. Taken together, results suggest that chronic MPH exposure at an early age in healthy animals changes mitochondrial dynamics, biogenesis and bioenergetics differently depending on the sex of the subjects.

Can stimulants make you smarter, despite stealing your sleep?

Nonmedical use of psychostimulants for cognitive enhancement is widespread and growing in neurotypical individuals, despite mixed scientific evidence of their effectiveness. Sleep benefits cognition, yet the interaction between stimulants, sleep, and cognition in neurotypical adults has received little attention. We propose that one effect of psychostimulants, namely decreased sleep, may play an important and unconsidered role in the effect of stimulants on cognition. We discuss the role of sleep in cognition, the alerting effects of stimulants in the context of sleep loss, and the conflicting findings of stimulants for complex cognitive processes. Finally, we hypothesize that sleep may be one unconsidered factor in the mythology of stimulants as cognitive enhancers and propose a methodological approach to systematically assess this relation.

Nonmedical Use of Stimulants Among Students in Jordan: A Nationwide Study

OBJECTIVES

Nonmedical use (NMU) of stimulants is an increasingly common phenomenon worldwide. Motivated by enhancing academic performance, peer pressure, and seeking pleasure, students in the Middle East are thought to be a high-risk population. This is especially important in times when the political instability in the region facilitates the production and trafficking of such substances. This study aimed to unveil the burden of NMU of stimulants and examine associated correlates among senior high school and university students in Jordan.

METHODS

We describe a cross-sectional study of senior high school and university students in Jordan assessing NMU of stimulants. Data were collected between January and April of 2022 through a survey, which was distributed online leading to a google forms page. The survey queried sociodemographic characteristics, history of NMU of stimulants, use of other illicit substances, attitudes toward NMU of stimulants, as well as a mental health assessment.

RESULTS

A total of 8739 students completed the survey (mean age of 20.40 ± 2.45 years), of which 5.1% reported a lifetime NMU of stimulants. Fenethylline (Captagon) was the most widely reported stimulant (2.6%). Living in the southern region, being diagnosed with a personality disorder, and using concomitant illicit substances were associated with the NMU of stimulants.

CONCLUSIONS

The NMU of CNS stimulants, especially fenethylline, is prevalent in Jordan. More surveillance ought to be heeded toward the southern borders of Jordan. Students who use stimulants for academic reasons must be made aware of the potential consequences of the NMU of stimulants.

Single use of psychoactive substances and its association with sleep disorders and sleep health in a large US college sample

OBJECTIVE

Estimate the association between single (i.e., exclusive) use of a range of substances and sleep outcomes.

PARTICIPANTS

College students participated in the 2015-2019 American College-Health Association-National College-Health Assessment survey.

METHODS

Multivariable logistic and linear regressions were used.

RESULTS

Single users of sedative, opioid, tobacco, and stimulant drugs were more likely to report a diagnosis of insomnia and other sleep disorder and indicated more days per week of negative sleep health outcomes compared not only to non-users of these substances but also polysubstance users. Single users of alcohol were significantly less likely to report a diagnosis of sleep disorder and indicated having had more days per week of positive sleep health outcomes compared to non-alcohol users and polysubstance users. However, those results are reversed for binge drinking.

CONCLUSIONS

Support of programs addressing behaviors to reduce the high prevalence of psychoactive substance use and sleep disturbances in college youth is needed.

Formulated Palmitoylethanolamide Supplementation Improves Parameters of Cognitive Function and BDNF Levels in Young, Healthy Adults: A Randomised Cross-Over Trial

BACKGROUND

Palmitoylethanolamide (PEA) is an endocannabinoid-like lipid mediator which is naturally produced in the body and found in certain foods. The aim of this study was to assess the effect of a bioavailable formulated form of PEA (Levagen+®) on serum BDNF levels and parameters of cognitive function in healthy adults.

METHODS

A randomised double-blinded placebo-controlled cross-over trial was implemented to measure the effects of a 6-week 700 mg/day course of formulated PEA supplementation versus a placebo. Participants (n = 39) completed pre- and post-assessments of a lab-based cognitive test. Serum samples were collected to measure BDNF concentrations using an immunoassay.

RESULTS

A significant increase in serum BDNF levels was found following PEA supplementation compared with the placebo (p = 0. 0057, d = 0.62). The cognition test battery demonstrated improved memory with PEA supplementation through better first success (p = 0.142, d = 0.54) and fewer errors (p = 0.0287; d = -0.47) on the Paired Associates Learning test.

CONCLUSION

This was the first study to report a direct beneficial effect of Levagen+® PEA supplementation on memory improvement as well as corresponding increases in circulating neurotrophic marker levels. This suggests that formulated PEA holds promise as an innovative and practical intervention for cognitive health enhancement.

Prevalence of the use of prescription stimulants as "study drugs" by UK university students: A brief report

INTRODUCTION

There is media concern over students using prescription stimulants as "cognitive enhancers" to try and improve their academic performance. However, there is limited evidence about the prevalence of this behaviour in the United Kingdom, or whether it has increased in recent years.

METHODS

We review survey studies on students' use of cognitive enhancers.

RESULTS

Overall reported use is low, with some inconclusive evidence that it is increasing. Use of modafinil appears to be higher than that of methylphenidate or dexamphetamine.

CONCLUSION

There is a clear need for large-scale research in this area, using representative sampling and survey methods that protect student anonymity.

Use of psychoactive substances among university students from 2019 to 2020: A systematic review

Psychoactive substances act on the central nervous system producing changes in mental processes, such as perception, consciousness, cognition or mood and emotions. The present study aims to identify: (i) the most used psychoactive substances, (ii) how psychoactive substances are acquired, (iii) and possible reasons for the use of psychoactive substances amongst university students. A literature search was carried out without language restrictions and included articles published between 2019 and 2020 in journals indexed in the electronic databases of Pubmed and Scielo. The inclusion criteria considered were: (i) original articles, (ii) studies carried out with university students, (iii) providing data on the use of psychoactive substances. 15 studies were included in this review, of which: 4 studies addressed possible reasons that lead to use of psychoactive substances, 10 studies reported usage profile and demographic data, and 1 study addressed how students acquire psychoactive substances. Reasons that led to the consumption of psychoactive substances include: feelings of loneliness after moving away from family; difficulty making new friends; poor academic performance and susceptible environment to acquisition of these substances. In the selected studies, alcohol was identified as the main drug used. In light of the findings reported in this review, new prevention and harm reduction measures can be formulated, based mainly on the reasons that lead to the use of psychoactive drugs, consumption patterns and how the drugs were acquired by university students.

Selenium alleviates modafinil-induced neurobehavioral toxicity in rat via PI3K/Akt/mTOR/GSK3B signaling pathway and suppression of oxidative stress and apoptosis: in vivo and in silico study

Nonmedical use of modafinil (MOD) led to increased rates of overdose toxicity, road accidents, addiction, withdrawal, suicide, and mental illnesses. The current study aims to determine the probable MOD brain toxicity and elucidate the possible role of selenium (Se) in ameliorating the neurotoxicity in rat models. Fifty-four male Albino rats were randomly assigned into nine groups. The groups were G1 (control negative), G2 (Se0.1), G3 (Se0.2), G4 (MOD300), G5 (MOD600), G6 (Se0.1 + MOD300), G7 (Se0.2 + MOD300), G8 (Se0.1 + MOD600), and G9 (Se0.2 + MOD600). After finishing the experiment, blood and brain tissue were harvested for biochemical and histological investigation. Neurobehavior parameters were assessed. Tissue neurotransmitter levels and oxidative stress markers were assessed. Gene expression of PI3K/Akt/mTOR-GSK3B, orexin, and orexin receptor2 was measured by qRT-PCR. Histological and immunohistochemistry assessments, as well as molecular docking, were carried out. MOD-induced neurobehavioral toxicity exhibited by behavioral and cognitive function impairments, which are associated with decreased antioxidant activities, increased MDA levels, and decreases in neurotransmitter levels. Brain levels of mRNA expression of PI3K, Akt, and mTOR were decreased, while GS3K, orexin, and orexin receptors were significantly elevated. These disturbances were confirmed by histopathological brain changes with increased silver and Bax immunostaining and decreased crystal violet levels. MOD induced neurotoxic effects in a dose-dependent manner. Compared with the MOD groups, SE coadministration significantly attenuates MOD-induced toxic changes. Docking study shows the protective role of Se as an apoptosis inhibitor and inflammation inhibitor. In conclusion, Se could be used as a biologically effective antioxidant compound to protect from MOD neurobehavioral toxicity in Wistar rats by reversing behavioral alterations, inflammation, apoptosis, and oxidative injury.

Enhancing Associative Learning in Rats With a Computationally Designed Training Protocol

Background

Learning requires the activation of protein kinases with distinct temporal dynamics. In Aplysia, nonassociative learning can be enhanced by a computationally designed learning protocol with intertrial intervals (ITIs) that maximize the interaction between fast-activated PKA (protein kinase A) and slow-activated ERK (extracellular signal-regulated kinase). Whether a similar strategy can enhance associative learning in mammals is unknown.

Methods

We simulated 1000 training protocols with varying ITIs to predict an optimal protocol based on empirical data for PKA and ERK dynamics in rat hippocampus. Adult male rats received the optimal protocol or control protocols in auditory fear conditioning and fear extinction experiments. Immunohistochemistry was performed to evaluate pCREB (phosphorylated cAMP response element binding)\protein levels in brain regions that have been implicated in fear acquisition.

Results

Rats exposed to the optimal conditioning protocol with irregular ITIs exhibited impaired extinction memory acquisition within the session using a standard footshock intensity, and stronger fear memory retrieval and spontaneous recovery with a weaker footshock intensity, compared with rats that received massed or spaced conditioning protocols with fixed ITIs. Rats exposed to the optimal extinction protocol displayed improved extinction of contextual fear memory and reduced spontaneous recovery compared with rats that received standard extinction protocols. Moreover, the optimal conditioning protocol increased pCREB levels in the dentate gyrus of the dorsal hippocampus, suggesting enhanced induction of long-term potentiation.

Conclusions

These findings demonstrate that a computational model-driven behavioral intervention can enhance associative learning in mammals and may provide insight into strategies to improve cognition in humans.

Exploring the understanding, source of availability and level of access of cognitive enhancers among university students in the United Arab Emirates: A qualitative study

OBJECTIVE

The use of prescription stimulants for cognitive enhancement by healthy university students, identified as the largest cohort of cognitive enhancer (CE) users, is of growing interest. The purpose of this study was to look at the understanding, perception, experience, and level of access of CEs among healthy university students in the United Arab Emirates (UAE).

METHODS

The study was conducted in six highly competitive university programmes. Semi-structured interviews were conducted with 18 university students to discuss their own experiences and those of their friends and peers regarding the use of prescription stimulants. In addition, semi-structured interviews were conducted with seven teaching faculty staff members (registered pharmacists and medical doctors) to explore their views on the use of CEs in their university.

RESULTS

Data were analysed thematically for the identification of themes and subthemes within the data using coding. It was found that, 'Adderall' was the most common prescribed CE drug and caffeine super strength pills were the most common non-prescribed CE drug, both reported to enhance concentration, motivation, and meet academic deadlines.

CONCLUSIONS

It is expected that the findings of this study will be of interest to a wide range of services in UAE universities. This will enable them to raise awareness about the use of CEs among students.

The role of executive functions in mediating the relationship between adult ADHD symptoms and hyperfocus in university students

BACKGROUND

Hyperfocus, a state of intense, narrow and prolonged attentional focus, has been associated with symptoms of attention-deficit/hyperactivity disorder (ADHD) in both clinical and non-clinical populations. Hyperfocus may be explained by difficulties in executive control, typically observed in ADHD.

AIMS

To investigate (1) whether ADHD and executive functions (EF) are associated with hyperfocus and (2) whether EF mediate the relationship between ADHD symptoms and hyperfocus.

METHODS AND PROCEDURES

A non-clinical sample of 380 university students (264 females) completed self-reports of ADHD, EF, hyperfocus and hyperfocus during rewarding activities.

OUTCOMES AND RESULTS

Increased difficulties in EF and severity of ADHD symptoms were significantly and positively correlated with a higher frequency of hyperfocus. Moreover, EF difficulties partially mediated the relationship between ADHD and hyperfocus (after controlling for sex and substance use), but not the relationship between ADHD and hyperfocus during rewarding activities.

CONCLUSIONS AND IMPLICATIONS

Difficulties in EF partially explained the higher frequency of hyperfocus, but not of hyperfocus during rewarding activities, among university students reporting more severe ADHD symptoms. Future research should investigate whether and how specific EF and other ADHD-related neurocognitive difficulties (e.g., reward sensitivity) contribute to various types of hyperfocus experiences in ADHD. WHAT THIS PAPER ADDS?: This paper is a first attempt to explain the relationship between adult ADHD symptoms and hyperfocus experiences. Our findings suggest that, although highly correlated, existing self-reports of hyperfocus measure different aspects of this experience: hyperfocus and reward-related hyperfocus. We replicate previous findings that indicated a greater frequency of both types of hyperfocus in ADHD. Additionally, we demonstrate a connection between EF difficulties and different aspects of hyperfocus. Finally, we extend previous findings by proposing that EF difficulties partially explain the relationship between ADHD and hyperfocus, but not the relationship between ADHD and reward-related hyperfocus. We hypothesize that other neurocognitive difficulties (e.g., reward sensitivity) may contribute to explain the relationship between ADHD and different aspects of hyperfocus.

Novel Energy Drink Improves Cognitive Function and Mood, without Influencing Myocardial Oxygen Demand or Ventricular Repolarization in Adult Gamers: A Randomized, Double-Blind, Placebo-Controlled, Crossover Trial

OBJECTIVES

To examine the efficacy of acute consumption of a novel energy drink (C4S) versus placebo for improving cognitive and gaming performance and mood. Secondarily, we examined the cardiovascular safety profile of acute C4S consumption.

METHODS

Forty-five healthy, young adult video gamers completed two experimental visits in randomized order where they consumed either C4S or a placebo and then completed a validated battery of neurocognitive tests, played five video games, and completed a mood state survey. Blood pressure (BP), heart rate (HR), oxygen saturation, and electrocardiogram measurements were taken at baseline and repeated throughout each visit.

RESULTS

Acute consumption of C4S improved cognitive flexibility (absolute mean or median difference [95% CI] = +4.3 [2.2-6.4]; p < 0.001; d = 0.63), executive function (+4.3 [2.3-6.3]; p < 0.001; d = 0.63), sustained attention (+2.1 [0.6-3.6]; p = 0.01; d = 0.44), motor speed (+2.9 [0.8-4.9]; p < 0.001; d = 0.44), psychomotor speed (+3.9 [0.1-7.7]; p = 0.04; d = 0.32) working memory (+1.0 [0.1-1.9]; p = 0.02; d = 0.35), and performance in the two-dimensional visuospatial game Tetris (+463 [-419-2,065] pts; p = 0.049; d = 0.30) compared to placebo. C4S also improved Fatigue-Inertia (-1 [-3-0]; p = 0.004; d = 0.45), Vigor-Activity (+2.4 [1.3-3.6]; p < 0.001; d = 0.64), Friendliness (+0 [0-1]; p = 0.04; d = 0.32), and Total Mood Disturbance (-3 [-6-0]; p = 0.002; d = 0.44). BP increased slightly in C4S versus placebo, while HR decreased from baseline to post-drink in the C4S condition. Rate-pressure-product was higher in C4S versus placebo independent of time but did not increase from baseline. There was no effect on corrected QT interval.

CONCLUSION

Acute consumption of C4S was efficacious for cognitive performance, visuospatial gaming performance, and mood enhancement, and had no effect on myocardial oxygen demand or ventricular repolarization, despite being associated with increases in BP.

An overview of the use of psychoactive substances among students at the University of Lille during the COVID-19 health crisis: Results of the PETRA study

OBJECTIVES

Students represent a population at risk for substance abuse. That risk may have been exacerbated by the COVID-19 pandemic. We aimed to describe substance abuse among students and to compare consumption according to the university field.

METHODS

A self-administered questionnaire was sent by email to all students at the University of Lille, France, between March and July 2021. This anonymous questionnaire included questions about sociodemographic characteristics, university courses and the use of psychoactive substances (frequency, reasons, routes of administration) since the first university year.

RESULTS

Among the 4431 students who responded (response rate 6.1%), eighty percent declared having used alcohol since the first university year, 34% cannabis, 15.4% benzodiazepines, 14.7% opioid drugs, 7.5% cocaine, 6.8% nitrous oxide and 6.5% MDMA. More than 20% of the users of cannabis, benzodiazepines, amphetamines and cocaine reported having already felt dependent. Recreational use was described by more than 10% of benzodiazepine or opioid drug users. Nitrous oxide use was significantly more frequent in the health and sport field (p < 0.001). Tobacco, benzodiazepine, cannabis and MDMA uses were significantly more frequent in the humanities and social sciences/art, language and literature fields (p < 0.001).

CONCLUSION

Prevention measures focusing on alcohol, cannabis, illicit psychostimulants, nitrous oxide and prescription drugs are required in the student population.

Modafinil, an atypical CNS stimulant?

Modafinil is a central nervous system stimulant approved for the treatment of narcolepsy and sleep disorders. Due to its wide range of biochemical actions, modafinil has been explored for other potential therapeutic uses. Indeed, it has shown promise as a therapy for cognitive disfunction resulting from neurologic disorders like ADHD, and as a smart drug in non-medical settings. The mechanism(s) of actions underlying the therapeutic efficacy of this agent remains largely elusive. Modafinil is known to inhibit the dopamine transporter, thus decreasing dopamine reuptake following neuronal release, an effect shared by addictive psychostimulants. However, modafinil is unique in that only a few cases of dependence on this drug have been reported, as compared to other psychostimulants. Moreover, modafinil has been tested, with some success, as a potential therapeutic agent to combat psychostimulant and other substance use disorders. Modafinil has additional, but less understood, actions on other neurotransmitter systems (GABA, glutamate, serotonin, norepinephrine, etc.). These interactions, together with its ability to activate selected brain regions, are likely one of the keys to understand its unique pharmacology and therapeutic activity as a CNS stimulant. In this chapter, we outline the pharmacokinetics and pharmacodynamics of modafinil that suggest it has an "atypical" CNS stimulant profile. We also highlight the current approved and off label uses of modafinil, including its beneficial effects as a treatment for sleep disorders, cognitive functions, and substance use disorders.

Trends in Stimulant and Sedative/Hypnotic Dispensing: An Exploratory Study

OBJECTIVE

To investigate patterns and trends of co-prescriptions of stimulants and sedatives within the last 6 years at a tertiary care center.

METHOD

Patients 18 years of age and older who were dispensed at least one stimulant prescription from an institutional pharmacy between 1/1/2015 and 7/1/2021 were included. Prescription data for any co-prescribed sedative/hypnotic were collected.

RESULTS

Both the number of stimulant dispenses and the number of patients with stimulant dispenses increased significantly with yearly incidence rate ratios of 1.115 (95% CI [1.110, 1.119]) and 1.090 (95% CI [1.084, 1.096]), respectively. The number of patients with a stimulant dispensed who also had a benzodiazepine or "Z-drug" sedative-hypnotic dispensed at any point in the search timeframe increased significantly with incidence rate ratios of 1.077 and 1.092, respectively. The number of stimulant dispenses, number of patients with stimulant dispenses, and number of patients with a stimulant dispensed who also had both a benzodiazepine and Z-drug dispensed at any point in the search timeframe increased significantly more in Non-White than in White patients.

CONCLUSIONS

The results confirm previous findings of increases in dispensing of stimulants over the past 6 years and report increased polypharmacy of stimulants and sedative-hypnotics.

Methylphenidate as a treatment option for substance use disorder: a transdiagnostic perspective

A transition in viewing mental disorders from conditions defined as a set of unique characteristics to one of the quantitative variations on a collection of dimensions allows overlap between disorders. The overlap can be utilized to extend to treatment approaches. Here, we consider the overlap between attention-deficit/hyperactivity disorder and substance use disorder to probe the suitability to use methylphenidate as a treatment for substance use disorder. Both disorders are characterized by maladaptive goal-directed behavior, impaired cognitive control, hyperactive phasic dopaminergic neurotransmission in the striatum, prefrontal hypoactivation, and reduced frontal cortex gray matter volume/density. In addition, methylphenidate has been shown to improve cognitive control and normalize associated brain activation in substance use disorder patients and clinical trials have found methylphenidate to improve clinical outcomes. Despite the theoretical basis and promising, but preliminary, outcomes, many questions remain unanswered. Most prominent is whether all patients who are addicted to different substances may equally profit from methylphenidate treatment.

Unauthorized ingredients in "nootropic" dietary supplements: A review of the history, pharmacology, prevalence, international regulations, and potential as doping agents

The first nootropic prohibited in sport was fonturacetam (4-phenylpiracetam, carphedon) in 1998. Presented here 25 years later is a broad-scale consideration of the history, pharmacology, prevalence, regulations, and doping potential of nootropics viewed through a lens of 50 selected dietary supplements (DS) marketed as "cognitive enhancement," "brain health," "brain boosters," or "nootropics," with a focus on unauthorized ingredients. Nootropic DS have risen to prominence over the last decade often as multicomponent formulations of bioactive ingredients presenting compelling pharmacological questions and potential public health concerns. Many popular nootropics are unauthorized food or DS ingredients according to the European Commission including huperzine A, yohimbine, and dimethylaminoethanol; unapproved pharmaceuticals like phenibut or emoxypine (mexidol); previously registered drugs like meclofenoxate or reserpine; EU authorized pharmaceuticals like piracetam or vinpocetine; infamous doping agents like methylhexaneamine or dimethylbutylamine; and other investigational substances and peptides. Several are authorized DS ingredients in the United States resulting in significant global variability as to what qualifies as a legal nootropic. Prohibited stimulants or ß2-agonists commonly used in "pre-workout," "weight loss," or "thermogenic" DS such as octodrine, hordenine, or higenamine are often stacked with nootropic substances. While stimulants and ß2-agonists are defined as doping agents by the World Anti-Doping Agency (WADA), many nootropics are not, although some may qualify as non-approved substances or related substances under catch-all language in the WADA Prohibited List. Synergistic combinations, excessive dosing, or recently researched pharmacology may justify listing certain nootropics as doping agents or warrant additional attention in future regulations.

Who Wants to Enhance Their Cognitive Abilities? Potential Predictors of the Acceptance of Cognitive Enhancement

With advances in new technologies, the topic of cognitive enhancement has been at the center of public debate in recent years. Various enhancement methods (e.g., brain stimulation, smart drugs, or working memory training) promise improvements in one's cognitive abilities such as intelligence and memory. Although these methods have been rather ineffective so far, they are largely available to the general public and can be applied individually. As applying enhancement might be accompanied by certain risks, it is important to understand which individuals seek to enhance themselves. For instance, individuals' intelligence, personality, and interests might predict their willingness to get enhanced. Thus, in a preregistered study, we asked 257 participants about their acceptance of various enhancement methods and tested predictors thereof, such as participants' psychometrically measured and self-estimated intelligence. While both measured and self-estimated intelligence as well as participants' implicit beliefs about intelligence, did not predict participants' acceptance of enhancement; a younger age, higher interest in science-fiction, and (partially) higher openness as well as lower conscientiousness did. Thus, certain interests and personality traits might contribute to the willingness to enhance one's cognition. Finally, we discuss the need for replication and argue for testing other potential predictors of the acceptance of cognitive enhancement.

Does chronic use of amphetamine-type stimulants impair interference control? - A meta-analysis

In substance use and addiction, inhibitory control is key to ignoring triggers, withstanding craving and maintaining abstinence. In amphetamine-type stimulant (ATS) users, most research focused on behavioral inhibition, but largely neglected the equally important subdomain of cognitive interference control. Given its crucial role in managing consumption, we investigated the relationship between interference control and chronic ATS use in adults. A database search (Pubmed & Web of Science) and relevant reviews were used to identify eligible studies. Effect sizes were estimated with random effects models. Subgroup, meta-regression, and sensitivity analyses explored heterogeneity in effect sizes. We identified 61 studies (53 datasets) assessing interference control in 1873 ATS users and 1905 controls. Findings revealed robust small effect sizes for ATS-related deficits in interference control, which were mainly seen in methamphetamine, as compared to MDMA users. The differential effects are likely due to tolerance-induced dopaminergic deficiencies (presumably most pronounced in methamphetamine users). Similarities between different ATS could be due to noradrenergic deficiencies; but elucidating their functional role in ATS users requires further/more research.

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

Methylphenidate is a stimulant used to treat attention deficit and hyperactivity disorder (ADHD). In the last decade, illicit use of methylphenidate has increased among healthy young adults, who consume the drug under the assumption that it will improve cognitive performance. However, the studies that aimed to assess the methylphenidate effects on memory are not consistent. Here, we tested whether the effect of methylphenidate on a spatial memory task can be explained as a motivational and/or a reward effect. We tested the effects of acute and chronic i.p. administration of 0.3, 1 or 3 mg/kg of methylphenidate on motivation, learning and memory by using the 8-arm radial maze task. Adult male Wistar rats learned that 3 of the 8 arms of the maze were consistently baited with 1, 3, or 6 sucrose pellets, and the number of entries and reentries into reinforced and non-reinforced arms of the maze were scored. Neither acute nor chronic (20 days) methylphenidate treatment affected the number of entries in the non-baited arms. However, chronic, but not acute, 1-3 mg/kg methylphenidate increased the number of reentries in the higher reward arms, which suggests a motivational/rewarding effect rather than a working memory deficit. In agreement with this hypothesis, the methylphenidate treatment also decreased the approach latency to the higher reward arms, increased the approach latency to the low reward arm, and increased the time spent in the high, but not low, reward arm. These findings suggest that methylphenidate may act more as a motivational enhancer rather than a cognitive enhancer in healthy people.

The ubiquity of the fallacy of composition in cognitive enhancement and in education

Research into cognitive enhancement is highly controversial, and arguments for and against it have failed to identify the logical fallacy underlying this debate: the fallacy of composition. The fallacy of composition is a lesser-known fallacy of ambiguity, but it has been explored and applied extensively to other fields, including economics. The fallacy of composition, which occurs when the characteristics of the parts of the whole are incorrectly extended to apply to the whole itself, and the conclusion is false, should be addressed in the debate on cognitive enhancement and within education. Within cognitive enhancement, the premise that individual distinct cognitive processes can be enhanced by cognitive enhancers leads to the conclusion that they must enhance cognition overall, and this idea is pervasive in the literature. If the goal of cognitive enhancement is to enhance cognition or learning, and not merely individual cognitive processes, then this is a clear example of the fallacy of composition. The ambiguity of "cognitive," "cognition," and "enhancement" only perpetuates this fallacy and creates more confusion surrounding the purposes and goals of enhancement. Identifying this fallacy does not threaten the existing body of research; however, it provides a novel framework to explore new avenues for research, education, and enhancement, particularly through education reform initiatives. Education enhances and facilitates learning, and improvements to education could be considered cognitive enhancements. Furthermore, the same fallacy is ubiquitous in education; educators commit it by "teaching to the test" and prioritizing memorization over generalizable skills such as critical thinking and problem solving. We will explore these new avenues for research and highlight principles of learning success from other disciplines to create a clearer understanding of the means and ends of cognitive enhancement. Recognizing the pervasiveness of composition fallacy in cognitive enhancement and education will lead to greater clarity of normative positions and insights into student learning that steer away from fallacious reasoning.

Methylphenidate use and misuse among medical residents in Israel: a cross-sectional study

BACKGROUND

Methylphenidate (MPH) and other stimulants may be misused, mainly as cognitive enhancers and recreational drugs. Data regarding misuse among medical residents are scarce. This study aimed to evaluate the prevalence of and main reasons for methylphenidate (MPH) use and misuse among Israeli medical residents.

METHODS

In this cross-sectional study, we sent an online questionnaire to medical residents who had completed their first residency exam and specialists with up to 2 years of experience. We asked about the use of MPH before and during residency and attitudes toward the use of MPH as a cognitive enhancer. We also added the Adult ADHD Self-Report Scale (ASRS) questionnaire, a validated tool used to screen for the presence of attention deficit hyperactivity disorder (ADHD). Users and misusers were classified based on self-report of use and formal ADHD diagnosis. Logistic regression analysis was used to evaluate factors associated with MPH misuse.

RESULTS

From March 2021 to August 2021, 370 physicians responded to our questionnaire (response rate 26.4%). Twenty-eight met the exclusion criteria and were not included. The respondents' average age was 36.5 years. Women comprised 63.5% of the respondents. Of the participants, 16.4% were classified as users and 35.1% as misusers. The prevalence of misusers was 45.6% among surgery and OB/GYN physicians, 39.4% among pediatricians and internists, and 24% among family physicians (P < 0.001). Misusers had a more liberal approach than others to MPH use as a cognitive enhancer. Factors associated with misuse of MPH included not being a native-born Israeli (OR-1.99, 95% CI 1.08, 3.67) and type of residency (OR-2.33, 95% CI 1.22, 4.44 and OR-4.08, 95% CI 2.06, 8.07 for pediatrics and internal medicine and surgery, respectively).

CONCLUSION

Very high levels of MPH misuse during residency may be related to stress, long working hours, night shifts, and the academic burden of the residency period. We believe that our findings should be considered by healthcare policymakers as they make decisions regarding the conditions of medical residencies. The use of MPH as a cognitive enhancer should be further studied and discussed.

Cardiovascular Activity of Ginkgo biloba-An Insight from Healthy Subjects

Ginkgo biloba is the oldest living tree species in the world. Despite less than encouraging clinical results, extracts from its leaves are among the most used herbal preparations in the prevention and treatment of cardiovascular diseases. Most data on the efficacy of Ginkgo biloba on cardiovascular disease is from clinical studies, with few results from healthy subjects. This paper aims to provide a comprehensive review of the mechanisms underlying the known beneficial cardiovascular activities of Ginkgo biloba. It displays myocardial suppressant and vasorelaxant activities ex vivo, potentiating endothelial-dependent and -independent pathways. It improves perfusion in different vascular beds, namely ocular, cochlear, cutaneous, cerebral, and coronary. Although scarce, evidence suggests that Ginkgo biloba displays a heterogeneous effect on tissue perfusion which is dependent on the individual elimination pathways. It displays an acceptable safety profile, with most reported adverse reactions constituting rare occurrences. Collectively, Ginkgo biloba positively impacts cardiovascular physiology, improving hemodynamics and organ perfusion. In the future, better controlled clinical studies should be performed in order to identify the target populations who may benefit the most from pharmacotherapeutic interventions involving Ginkgo biloba.

Better characterization of attention and hyperactivity/impulsivity in children with ADHD: The key to understanding the underlying white matter microstructure

The apparent increase in the prevalence of the attention deficit hyperactivity disorder (ADHD) diagnosis raises many questions regarding the variability of the subjective diagnostic method. This comprehensive review reports findings in studies assessing white matter (WM) bundles in diffusion MRI and symptom severity in children with ADHD. These studies suggested the involvement of the connections between the frontal, parietal, and basal ganglia regions. This review discusses the limitations surrounding diffusion tensor imaging (DTI) and suggests novel imaging techniques allowing for a more reliable representation of the underlying biology. We propose a more inclusive approach to studying ADHD that includes known endophenotypes within the ADHD diagnosis. Aligned with the Research Domain Criteria Initiative, we also propose to investigate attentional capabilities and impulsive behaviours outside of the borders of the diagnosis. We support the existing hypothesis that ADHD originates from a developmental error and propose that it could lead to an accumulation in time of abnormalities in WM microstructure and pathways. Finally, state-of-the-art diffusion processing and novel artificial intelligence approaches would be beneficial to fully understand the pathophysiology of ADHD.

Stimulant abuse as a coping strategy-Forensic and criminal consequences of stimulant abuse for neuroenhancement

Pharmacological neuroenhancement (PN) describes the use of divergent psychoactive substances to enhance mental performance (cognition) without medical need. This kind of substance abuse takes place predominantly in stressful situations. Users implicitly-or even explicitly-describe this kind of drug abuse to be a coping strategy. Regarding the decision making process whether to use PN drugs or not, users indicate that legal aspects to be decisive. However, the legal situation has been neglected so far. To elucidate the German legal situation, PN substances have to be divided into over-the-counter drugs, prescription drugs and illegal drugs. Amphetamines have the highest cognition-enhancing potential, followed by modafinil and caffeine-containing substances. It is pointed out that the use of both freely available and prescription PN substances and narcotics without medical indication have so far been largely exempt from punishment under German law. However, individuals (physicians, bus and truck drivers, etc.) taking PN substances may expose others at risk due to wrong decisions (driving or treatment), errors based on side effects of the used substances. Therefore, the protection of life and health of others could legitimize criminal regulation.

Opinions towards Medical Students' Self-Care and Substance Use Dilemmas-A Future Concern despite a Positive Generational Effect?

This study examines demographic factors which may influence opinions concerning medical students' self-care and substance use behaviors as a means of providing insights into how future doctors view these issues compared to Australian doctors and members of the public. We conducted national, multicenter, prospective, on-line cross-sectional surveys using hypothetical scenarios to three cohorts- Australian medical students, medical doctors, and the public. Participants' responses were compared for the different contextual variables within the scenarios and the participants' demographic characteristics. In total 2602 medical students, 809 doctors and 503 members of the public participated. Compared with doctors and the public, medical students were least tolerant of alcohol intoxication, and most tolerant of using stimulants to assist with study, and cannabis for anxiety. Doctor respondents more often aligned with the public's opinions on the acceptability of the medical students' behaviors. Although opinions are not equivalent to behaviour, Australian students' views on the acceptability for cannabis to help manage anxiety, and inappropriate use of prescription-only drugs are concerning; these future doctors will be responsible for prescribing drugs and managing patients with substance abuse problems. However, if current Australian medical student's opinions on alcohol misuse persist, one of the commonest substance addictions amongst doctors may decrease in future.

Preparation of Deuterium-Labeled Armodafinil by Hydrogen–Deuterium Exchange and Its Application in Quantitative Analysis by LC-MS

Armodafinil, the R enantiomer of modafinil, was approved in 2007 by the US Food and Drug Administration as a wake-promoting agent for excessive sleepiness treatment. Due to its abuse by students and athletes, there is a need of its quantification. Quantitative analysis by liquid chromatography-mass spectrometry, however, though very common and sensitive, frequently cannot be performed without isotopically labeled standards which usually have to be specially synthesized. Here we reported our investigation on the preparation of deuterated standard of armodafinil based on the simple and inexpensive hydrogen–deuterium exchange reaction at the carbon centers. The obtained results clearly indicate the possibility of introduction of three deuterons into the armodafinil molecule. The introduced deuterons do not undergo back exchange under neutral and acidic conditions. Moreover, the deuterated and non-deuterated armodafinil isotopologues revealed co-elution during the chromatographic analysis. The ability to control the degree of deuteration using different reaction conditions was determined. The proposed method of deuterated armodafinil standard preparation is rapid, cost-efficient and may be successfully used in its quantitative analysis by LC-MS.

Effects of Smart Drugs on Cholinergic System and Non-Neuronal Acetylcholine in the Mouse Hippocampus: Histopathological Approach

In recent years, people in the United States and other countries have been using smart drugs, called nootropic or cognitive enhancers, to improve concentration and memory learning skills. However, these drugs were originally prescribed for attention-deficit hyperactivity disorder and dementia, and their efficacy in healthy people has not yet been established. We focused on acetylcholine in the hippocampus, which is responsible for memory learning, and elucidate the long-term effects of smart drugs on the neural circuits. Smart drugs were administered orally in normal young mice for seven weeks. The hippocampus was sectioned and compared histologically by hematoxylin and eosin (HE) staining, immunohistochemistry for acetylcholine, and immunoelectron microscopy. There were no significant changes in acetylcholinesterase staining. However, in HE, we found perivascular edema, and choline acetyltransferase staining showed increased staining throughout the hippocampus and new signal induction in the perivascular area in the CA3, especially in the aniracetam and α-glyceryl phosphoryl choline group. Additionally, new muscarinic acetylcholine receptor signals were observed in the CA1 due to smart drug intake, suggesting that vasodilation might cause neuronal activation by increasing the influx of nutrients and oxygen. Moreover, these results suggest a possible new mechanism of acetylcholine-mediated neural circuit activation by smart drug intake.

Benefits and Harms of 'Smart Drugs' (Nootropics) in Healthy Individuals

'Smart drugs' (also known as 'nootropics' and 'cognitive enhancers' [CEs]) are being used by healthy subjects (i.e. students and workers) typically to improve memory, attention, learning, executive functions and vigilance, hence the reference to a 'pharmaceutical cognitive doping behaviour'. While the efficacy of known CEs in individuals with memory or learning deficits is well known, their effect on non-impaired brains is still to be fully assessed. This paper aims to provide an overview on the prevalence of use; putative neuroenhancement benefits and possible harms relating to the intake of the most popular CEs (e.g. amphetamine-type stimulants, methylphenidate, donepezil, selegiline, modafinil, piracetam, benzodiazepine inverse agonists, and unifiram analogues) in healthy individuals. CEs are generally perceived by the users as effective, with related enthusiastic anecdotal reports; however, their efficacy in healthy individuals is uncertain and any reported improvement temporary. Conversely, since most CEs are stimulants, the related modulation of central noradrenaline, glutamate, and dopamine levels may lead to cardiovascular, neurological and psychopathological complications. Furthermore, use of CEs can be associated with paradoxical short- and long-term cognitive decline; decreased potential for plastic learning; and addictive behaviour. Finally, the non-medical use of any potent psychotropic raises serious ethical and legal issues, with nootropics having the potential to become a major public health concern. Further studies investigating CE-associated social, psychological, and biological outcomes are urgently needed to allow firm conclusions to be drawn on the appropriateness of CE use in healthy individuals.

Exploring the use of cognitive enhancement substances among Portuguese university students

Background

Prescription drug use and the consumption of substances to enhance college students' cognitive performance, described as pharmacological cognitive enhancement (PCE), is a known phenomenon potentially impacting individuals' health. University and college students are two specific subpopulations noted to use PCE (up to 17%, on average). To our knowledge, no data have been published on the use of PCE drugs among university students at a national level in Portugal and the factors that might be associated with this usage.

Objective

The main objective was to estimate the prevalence of PCE use by Portuguese university students and to identify the PCE substances commonly used by university students, i.e., those classified as prescription drugs and other legal and nonprescribed substances, including food supplements.

Methods

The study followed a cross-sectional exploratory, descriptive design and pursued a convenience sample of students from Portuguese public and private universities (22 higher education institutions).

Results

From a sample of 745 university students, 32% indicated the use of prescribed and nonprescribed substances. The most consumed substances were food supplements with CNS stimulants being the most frequent prescription-only drugs but not necessarily accessed through a medical prescription. A significant statistical association was found between substance consumption and the field of study. Health science students reported more food supplements and drug intake, allegedly under prescribed regimens, compared to humanities and exact sciences students. The study discusses the need to better understand the competitive societies that produce and support young students' outputs and the perceived ‘need’ for performance-enhancing substances.

Conclusions

One-third of the university students aimed to improve their performance by pharmacological cognitive enhancement, with a preference for food supplements dispensed in pharmacies. PCE substance consumption in higher education is thus non-negligible. The study suggests the need to improve regulations on potential inequalities in academic rankings and success and an observant attitude concerning implications that negatively affect health in the long run.

Students' use of caffeine, alcohol, dietary supplements, and illegal substances for improving academic performance in a New Zealand university

This study aimed to describe patterns of use and attitudes towards a broad variety of substances for improving academic performance at a New Zealand university. 685 students (from 1800 invited) completed an online questionnaire (38% response rate). They were asked about their lifetime and current substance use for improving academic performance, as well as their reasons for use, attitudes and perceptions of: caffeine, alcohol, dietary supplements, prescription stimulants, other prescription substances, and illicit substances. 80% (95% CI: 76.3, 82.5) reported ever using any substance to help improve academic performance, mainly to stay awake and improve concentration. Caffeine (70%, 95% CI: 66.3, 73.3) and dietary supplements (32%, 95% CI: 28.3, 35.5) were most commonly used. 4% (95% CI: 2.7, 5.9) reported use of prescription stimulants, mostly methylphenidate, and another 4% (95% CI: 2.7, 5.9) reported using illicit substances for improving academic performance. Users of prescription stimulants were more likely than non-users to believe that they were safe, morally acceptable, and that they should be available legally for enhancing academic performance. We close with discussions on broadening the focus of substances for improving academic performance in public health debates. Further qualitative research from small countries is also needed to move towards a place-based approach for clarifying ethical implications, inform policy in universities, and understand how injustices are created through the use of and ability to purchase different substances.

Pharmacology of Drugs Used as Stimulants

Psychostimulant, cardiovascular, and temperature actions of stimulants involve adrenergic (norepinephrine), dopaminergic (dopamine), and serotonergic (serotonin) pathways. Stimulants such as amphetamine, 3,4-methylenedioxymethamphetamine (MDMA), or mephedrone can act on the neuronal membrane monoamine transporters NET, DAT, and SERT and/or the vesicular monoamine transporter 2 to inhibit reuptake of neurotransmitter or cause release by reverse transport. Stimulants may have additional effects involving pre- and postsynaptic/junctional receptors for norepinephrine, dopamine, and serotonin and other receptors. As a result, stimulants may have a wide range of possible actions. Agents with cocaine or MDMA-like actions can induce serious and potentially fatal adverse events via thermodysregulatory, cardiovascular, or other mechanisms. MDMA-like stimulants may cause hyperthermia that can be life threathening. Recreational users of stimulants should be aware of the dangers of hyperthermia in a rave/club environment.

Psychostimulant Use Disorder, an Unmet Therapeutic Goal: Can Modafinil Narrow the Gap?

The number of individuals affected by psychostimulant use disorder (PSUD) has increased rapidly over the last few decades resulting in economic, emotional, and physical burdens on our society. Further compounding this issue is the current lack of clinically approved medications to treat this disorder. The dopamine transporter (DAT) is a common target of psychostimulant actions related to their use and dependence, and the recent availability of atypical DAT inhibitors as a potential therapeutic option has garnered popularity in this research field. Modafinil (MOD), which is approved for clinical use for the treatment of narcolepsy and sleep disorders, blocks DAT just like commonly abused psychostimulants. However, preclinical and clinical studies have shown that it lacks the addictive properties (in both behavioral and neurochemical studies) associated with other abused DAT inhibitors. Clinical availability of MOD has facilitated its off-label use for several psychiatric disorders related to alteration of brain dopamine (DA) systems, including PSUD. In this review, we highlight clinical and preclinical research on MOD and its R-enantiomer, R-MOD, as potential medications for PSUD. Given the complexity of PSUD, we have also reported the effects of MOD on psychostimulant-induced appearance of several symptoms that could intensify the severity of the disease (i.e., sleep disorders and impairment of cognitive functions), besides the potential therapeutic effects of MOD on PSUD.

Psychiatric Comorbidity and Stress in Medical Students Using Neuroenhancers

Background: Pharmacological neuroenhancement (PN) is a common healthcare problem at least among students. PN seems to be associated with stressful situations. There is a lack of data about personal characteristics, comorbidities, and coping strategies regarding stress and factors of resilience in students and medical staff. Methods: A web-based survey about the non-medical use of PN drugs with a focus on neuroenhancement was developed and distributed among medical students throughout Germany; the questionnaire was open in April and May of 2020. The survey contained questions about the use of well-known PN drugs, frequency, special purposes, reasons for the use, psychiatric disorders, use of psychotropic drugs apart from PN purposes, and factors of resilience using the brief resilience scale. Results: Data of 1,159 students of medicine were analyzed. The most frequently used substances for PN were coffee (78.8% lifetime prevalence rate), energy drinks (45.7%), caffeine tablets (24.3%), methylphenidate (5.2%), illicit amphetamines (2.0%), and cocaine (1.7%). 98.4% suspected that PN drug use could lead to addiction. PN drug use specifically for PN was significantly associated with the use of (a) any psychotropic drug (other than neuroenhancers), (b) any psychiatric disorder, and (c) higher values of feeling pressure to perform in professional/students' life and in private life as well as (d) the subjective feeling of pressure to perform to be burdening and (e) harmful to one's own health. PN drug use in general was significantly associated with being less resilient. The use of illicit PN drugs, over the counter drugs and prescription drugs was associated with being less resilient. Conclusion: This study indicates that PN with legal and illegal drugs is a widespread phenomenon among German medical students. Users seem to be more often burdened by psychiatric disorders, especially addictive disorders, the perception of stress, pressure to perform and low levels of resilience. These aspects should be considered in further investigation of PN drug use.

Effects of Appearance- and Performance-Enhancing Drugs on Personality Traits

Appearance- and performance-enhancing drugs (APEDs) are commonly used by adolescents and young adults in an effort to improve not only athletic performance but also physical and mental efficiency and sexual appearance. The rationale for using these drugs is grounded in the perceived importance of external appearance, the quest for health and youth, and the urge to boost one's sexual performances. Although APED users tend to be quite moderate overall, some specific subpopulations can display pathological use associated with high-risk behaviors. A wide and diverse range of APEDs is now easily accessible to almost anyone through backdoor online avenues. Common APEDs include anabolic-androgenic steroids, non-steroidal anabolics, anorectics, diuretics and ergo/thermogenics, nootropics or "cognition enhancers," licit and illicit psychostimulants, and finally, sexual enhancers. The use of APEDs appears linked to several psychopathological disorders of unclear prevalence, e.g., body image disorders and eating disorders, perfectionism, but also depression and loneliness. The role of personality traits related to APED use has been investigated in adolescents and young adults, in elite and amateur athletes, and in chemsexers and associated with the above-reported personality traits. The studies herein analyzed show that APED consumption in the general population is quickly growing into a public health concern. It is therefore essential to launch prevention and intervention projects aimed at promoting safe instrumental use of the body, not only in sports disciplines but also among the general population, and to promote psychological aid procedures for people with substance use issues, depression and anxiety, and body image disorders.