Modafinil and methylphenidate for neuroenhancement in healthy individuals: A systematic review

Behavioral and neurophysiological signatures of cognitive control in humans and rats

BACKGROUND

Deficits in cognitive control are implicated in numerous neuropsychiatric disorders. However, relevant pharmacological treatments are limited, likely due to weak translational validity of applicable preclinical models used. Neural indices derived from electroencephalography may prove useful in comparing and translating the effects of cognition-enhancing drugs between species. In the current study, we aimed to extend our previous cross-species results by examining if methylphenidate (MPH) modulates behavioral and neural indices of cognitive control in independent cohorts of humans and rats.

METHODS

We measured continuous electroencephalography data from healthy adults (n = 25; 14 female) and Long Evans rats (n = 22; 8 female) and compared both stimulus- and response-locked event-related potentials and spectral power measures across species, and their MPH-related moderation following treatment with vehicle (placebo) or 1 of 2 doses of MPH.

RESULTS

Across both species, linear mixed effects modeling confirmed the expected Flanker interference effect on behavior (eg, accuracy) and response-related event-related potentials. Unexpectedly, in contrast to past work, we did not observe any task-related effects on the spectral power of rodents. Moreover, MPH generally did not modulate cognitive control of either species, although some species-specific patterns offer insight for future research.

CONCLUSIONS

Collectively, these findings in independent human and rodent subjects replicate some of our previously reported behavioral and neurophysiological patterns partly consistent with the notion that similar neural mechanisms may regulate cognitive control in both species. Nonetheless, these results showcase an approach to accelerate translation using a coordinated between-species platform to evaluate pro-cognitive treatments.

Development and Validation of an Analytical Method to Identify and Quantitate Novel Modafinil Analogs in Products Marketed as Dietary Supplements

Modafinil (brand name Provigil®) is a Schedule IV (U.S.) drug used for the treatment of narcolepsy and sleep disorders. It is also known to be used recreationally. Analogs of modafinil, including adrafinil, remain unapproved and/or unscheduled. The lack of scheduling has made these analogs a popular target for recreational use and inclusion in dietary supplements. However, the use of controlled substances (or their analogs) without the care of a physician presents a public health risk. Preliminary nontargeted analyses in our laboratory revealed the presence of adrafinil in several dietary supplements, highlighting the need for an analytical method to identify modafinil analogs in supplements. A liquid chromatography high resolution mass spectrometry (LC-HRMS) method was developed and validated to quantitate modafinil, plus four novel unscheduled modafinil analogs: adrafinil, CRL-40,940, CRL-40,941, and N-methyl-4,4-difluoromodafinil. This method was then applied to four samples of products marketed as dietary supplements collected via undercover purchase. These four products were marketed as nootropics or cognitive enhancers and labeled to contain adrafinil. Adrafinil was found in all four samples. The identification of modafinil analogs in this context is important so that consumers are not, knowingly or unknowingly, consuming these active pharmaceutical ingredients in products marketed as dietary supplements.

Caffeine and modafinil modulate the effects of sleep deprivation on thalamic resting-state functional connectivity: A double-blind pilot study

BACKGROUND

Studies have found that the use of clinically approved caffeine and modafinil can alleviate cognitive impairment due to sleep deprivation (SD) to some extent. However, the neural mechanisms by which these two cognitive enhancers work to counteract the effects of SD on cognitive impairment remain unclear.

METHODS

A double-blind within-subjects experiment using resting-state functional magnetic resonance imaging (rs-fMRI) was designed. Participants underwent three 36-h SD trials, each of which involved taking 200 mg of caffeine, modafinil, or placebo at the 28th and 32 nd h of SD. Sixteen subregions of the thalamus were selected as the regions of interest and changes in functional connectivity (FC) between the thalamus and the other brain regions were explored after the participants took caffeine or modafinil.

RESULTS

The subjective sleepiness of the participants increased with the duration of SD. compared with placebo, modafinil and caffeine had insignificant effects on wakefulness or sleepiness. However, in terms of neural FC, we found varying degrees of attenuation or enhancement of the FC between the thalamus and other regions. Taking caffeine during SD weakened the FC between the right rostral temporal thalamus (rTtha) subregion and the left lingual gyrus compared with placebo. Caffeine enhanced the FC between three subregions of the thalamus, namely the left sensory thalamus, the left rTtha, and the right lateral pre-frontal thalamus, and the right inferior temporal, left orbitofrontal, and right superior occipital gyris. Modafinil weakened the FC between the right posterior parietal thalamus and left middle temporal gyrus, and enhanced the FC between the left medial pre-frontal thalamus, left rTtha, and right occipital thalamus and left middle frontal gyrus.

CONCLUSIONS

After 36 h of total SD, modafinil and caffeine administration enhanced or attenuated the time-domain correlations between various subregions of the thalamus and brain regions of the frontal and temporal lobes in healthy adults, compared with placebo. These results provide valuable evidence for further unraveling the neuropharmacological mechanisms of caffeine and modafinil, as well as important insights for exploring effective pharmacological intervention strategies against SD.

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.

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.

The rising use of cognitive enhancement drugs and predictors of use during COVID-19: findings from a cross-sectional survey of students and university staff in the UK

Background

The use of psychoactive substances to increase cognitive performance while studying has been termed 'pharmacological cognitive enhancement' (PCE). In previous years, several large-scale national surveys have focused on their use by students at university, including drug types, prevalence rates, and predictive factors. The recent coronavirus pandemic brought about widespread structural changes for UK universities, as students were forced to adapt to home-based learning and in many cases reduced academic support. No study has yet focused primarily on the impact of pandemic social restrictions on PCE in students and academic staff, and whether personality and demographic factors reveal user profiles that predict use during the pandemic period.

Method

A convenience sample of 736 UK students and staff aged 18-54 (M = 22.2, SD = 5.2) completed a cross-sectional survey assessing PCE prevalence rates, polydrug use, perceived effects, academic self-efficacy and personality during the first year of social restrictions (March 2020 - February 2021) compared with the previous year (March 2019 - February 2020).

Results

There was a significant self-reported rise in the use of all drug types (all ps < 0.001) during social restrictions, particularly with Modafinil (+42%), nutraceuticals (+30.2%) and microdose LSD (+22.2%). Respondents also indicated stronger PCE effects for all substances, except alcohol, in comparison to the previous year. Polydrug use with modafinil and other prescription stimulants increased the most during social restrictions. Personality factors and gender identity reliably predicted PCE use and lower agreeableness was often the strongest predictor, followed by identifying as male and lower conscientiousness. Academic self-efficacy and student/academic staff status were not consistent predictors.

Conclusion

This is the first survey of UK students to investigate PCE during coronavirus social restrictions and to assess predictive factors. Findings reveal a rise in PCE use and polydrug use which we suggest is because of increased pressures on students created by the lockdown and reduced access to university resources.

Categorical and dimensional aspects of stimulant medication effects in adult patients with ADHD and healthy controls

Psychiatric disorders are categorized on the basis of presence and absence of diagnostic criteria using classification systems such as the international classification of diseases (ICD) and the diagnostic and statistical manual for mental disorders (DSM). The research domain criteria (RDoC) initiative provides an alternative dimensional framework for conceptualizing mental disorders. In the present paper, we studied neural and behavioral effects of central stimulant (CS) medication in adults with attention deficit hyperactivity disorder (ADHD) and healthy controls using categorical and dimensional stratifications. AX-Continuous Performance Task (AX-CPT) was utilized for the later purpose, and participants were classified as "reactive" or "proactive" based on their baseline proactive behavioral index (PBI). Out of the 65 individuals who participated (33 healthy controls and 32 patients with ADHD), 53 were included in the final analysis that consisted of 31 healthy controls and 22 ADHD patients. For the dimensional stratification, a median split of PBI scores divided participants into "reactive" and "proactive" groups irrespective of whether they had ADHD or not. Participants performed AX-CPT in conjunction with functional magnetic resonance imaging (fMRI) before and after CS medication. We found no significant within or between group CS effect when participants were categorically assigned as healthy controls and ADHD patients. For the dimensional stratification, however, CS selectively increased activation in frontoparietal cognitive areas and induced a shift towards proactive control mode in the reactive group, without significantly affecting the proactive group. In conclusion, the neural and behavioral effects of CS were more clear-cut when participants were stratified into dimensional groups rather than diagnostic categories.

Methamphetamine-induced adaptation of learning rate dynamics depend on baseline performance

The ability to calibrate learning according to new information is a fundamental component of an organism's ability to adapt to changing conditions. Yet, the exact neural mechanisms guiding dynamic learning rate adjustments remain unclear. Catecholamines appear to play a critical role in adjusting the degree to which we use new information over time, but individuals vary widely in the manner in which they adjust to changes. Here, we studied the effects of a low dose of methamphetamine (MA), and individual differences in these effects, on probabilistic reversal learning dynamics in a within-subject, double-blind, randomized design. Participants first completed a reversal learning task during a drug-free baseline session to provide a measure of baseline performance. Then they completed the task during two sessions, one with MA (20 mg oral) and one with placebo (PL). First, we showed that, relative to PL, MA modulates the ability to dynamically adjust learning from prediction errors. Second, this effect was more pronounced in participants who performed poorly at baseline. These results present novel evidence for the involvement of catecholaminergic transmission on learning flexibility and highlights that baseline performance modulates the effect of the drug.

EEG Correlates of Moral Decision-Making: Effect of Choices and Offers Types

BACKGROUND

Moral decision-making consists of a complex process requiring individuals to evaluate potential consequences of personal and social decisions, including applied organizational contexts.

METHODS

This research aims to investigate the behavioral (offer responses and reaction times, RTs) and electrophysiological (EEG) correlates underlying moral decision-making during three different choice conditions (professional fit, company fit, and social fit) and offers (fair, unfair, and neutral).

RESULTS

An increase of delta and theta frontal activity (related to emotional behavior and processes) and beta frontal and central activity (linked to cognitive and attentional processes) was found. A left beta, delta, and theta frontal activity was observed for fair offers in professional fit conditions, while increased right frontal delta and theta activity was found in response to unfair offers in company fit conditions. Also, an increase of left delta and theta parietal activity for unfair offers in social fit condition was detected. Finally, higher accepted responses were found for fair and neutral offers in professional and social fit conditions, with increased RTs for unfair offers suggesting decisions' cognitive load and complexity.

CONCLUSIONS

By revealing a greater involvement of left and right frontal areas in decision-making processes based on choices and offers, personal interest evaluations and emotional values, and of parietal areas in more prosocial and altruistic moral behavior, current findings provide information about the neural and behavioral correlates underlying company moral behavior.

Adapting Ourselves, Instead of the Environment: An Inquiry into Human Enhancement for Function and Beyond

Technology enables humans not only to adapt their environment to their needs but also to modify themselves. Means of Human Enhancement - embodied technologies to improve the human body's capabilities or to create a new one - are the designated means of adapting ourselves instead of the environment. The debate about these technologies is typically fought on ethical soil. However, alarmist, utopian, and science fiction scenarios distract from the fact that Human Enhancement is a historical and pervasive phenomenon incorporated into many everyday practices. In the vein of disentangling conceptual difficulties, we claim that means of Human Enhancement are either physiologically or psychologically embodied, rendering the merging with the human user their most defining aspect. To fulfill its purpose, an enhancement must pass the test-in-the-world, i.e., assisting with effective engagement with a dynamic world. Even if failing in this regard: Human Enhancement is the fundamental and semi-targeted process of changing the users relationship with the world through the physical or psychological embodiment of a hitherto external object and/or change of one's body. This can potentially change the notion of being human. Drawing on a rich body of theoretical and empirical literature, we aim to provide a nuanced analysis of the transformative nature of this phenomenon in close proximity to human practice. Stakeholders are invited to apply the theory presented here to interrogate their perspective on technology in general and Human Enhancement in particular.

Methylphenidate Ameliorates Behavioural and Neurobiological Deficits in Executive Function for Patients with Chronic Traumatic Brain Injury

(1) Background: Traumatic brain injury (TBI) often results in cognitive impairments, including in visuospatial planning and executive function. Methylphenidate (MPh) demonstrates potential improvements in several cognitive domains in patients with TBI. The Tower of London (TOL) is a visuospatial planning task used to assess executive function. (2) Methods: Volunteers with a history of TBI (n = 16) participated in a randomised, double-blinded, placebo-controlled, fMRI study to investigate the neurobiological correlates of visuospatial planning and executive function, on and off MPh. (3) Results: Healthy controls (HCs) (n = 18) and patients on placebo (TBI-placebo) differed significantly in reaction time (p < 0.0005) and accuracy (p < 0.0001) when considering all task loads, but especially for high cognitive loads for reaction time (p < 0.001) and accuracy (p < 0.005). Across all task loads, TBI-MPh were more accurate than TBI-placebo (p < 0.05) but remained less accurate than HCs (p < 0.005). TBI-placebo substantially improved in accuracy with MPh administration (TBI-MPh) to a level statistically comparable to HCs at low (p = 0.443) and high (p = 0.175) cognitive loads. Further, individual patients that performed slower on placebo at low cognitive loads were faster with MPh (p < 0.05), while individual patients that performed less accurately on placebo were more accurate with MPh at both high and low cognitive loads (p < 0.005). TBI-placebo showed reduced activity in the bilateral inferior frontal gyri (IFG) and insulae versus HCs. MPh normalised these regional differences. MPh enhanced within-network connectivity (between parietal, striatal, insula, and cerebellar regions) and enhanced beyond-network connectivity (between parietal, thalamic, and cerebellar regions). Finally, individual changes in cerebellar-thalamic (p < 0.005) and cerebellar-parietal (p < 0.05) connectivity with MPh related to individual changes in accuracy with MPh. (4) Conclusions: This work highlights behavioural and neurofunctional differences between HCs and patients with chronic TBI, and that adverse differences may benefit from MPh treatment.

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 Atypical Dopamine Transporter Inhibitor CE-158 Enhances Dopamine Neurotransmission in the Prefrontal Cortex of Male Rats: A Behavioral, Electrophysiological, and Microdialysis Study

BACKGROUND

Dopamine plays a key role in several physiological functions such as motor control, learning and memory, and motivation and reward. The atypical dopamine transporter inhibitor S,S stereoisomer of 5-(((S)-((S)-(3-bromophenyl)(phenyl)methyl)sulfinyl)methyl)thiazole (CE-158) has been recently reported to promote behavioral flexibility and restore learning and memory in aged rats.

METHODS

Adult male rats were i.p. administered for 1 or 10 days with CE-158 at the dose of 1 or 10 mg/kg and tested for extracellular dopamine in the medial prefrontal cortex by means of intracerebral microdialysis and single unit cell recording in the same brain area. Moreover, the effects of acute and chronic CE-158 on exploratory behavior, locomotor activity, prepulse inhibition, working memory, and behavioral flexibility were also investigated.

RESULTS

CE-158 dose-dependently potentiated dopamine neurotransmission in the medial prefrontal cortex as assessed by intracerebral microdialysis. Moreover, repeated exposure to CE-158 at 1 mg/kg was sufficient to increase the number of active pyramidal neurons and their firing frequency in the same brain area. In addition, CE-158 at the dose of 10 mg/kg stimulates exploratory behavior to the same extent after acute or chronic treatment. Noteworthy, the chronic treatment at both doses did not induce any behavioral alterations suggestive of abuse potential (e.g., motor behavioral sensitization) or pro-psychotic-like effects such as disruption of sensorimotor gating or impairments in working memory and behavioral flexibility as measured by prepulse inhibition and Y maze.

CONCLUSIONS

Altogether, these findings confirm CE-158 as a promising pro-cognitive agent and contribute to assessing its preclinical safety profile in a chronic administration regimen for further translational testing.

On pharmacological neuroenhancement as part of the new neurorights' pioneering legislation in Chile: a perspective

The so-called neurorights are emerging human rights, or rather reconfigurations of already existing human rights, seeking to address the impact of the possible misuse of neurotechnologies, which have the potential to become more invasive and harmful in the future if not regulated. The aim of specifying neurorights is to protect the dignity and autonomy of the individual in the face of neurotechnological advances. Recently, Chile proposed a Constitutional reform inspired by the neurorights, opening a debate. One of the proposed neurorights is fair and equitable access to cognitive enhancement, which will be the specific object of this perspective article. Starting from the legal proposal, we analyse and discuss some perspectives on cognitive enhancement, or "neuroenhancement", which could be considered as part of enhancement neurotechnologies, pointing out that pharmacological enhancers, or "smart drugs", might be considered as part of these enhancers. We present a classification of the different types of cognitive enhancements as it has been proposed in the literature, into which pharmacological cognitive enhancement can be included, concluding that there is currently no agreement amongst scholars and lawyers about the ethical consideration of pharmacological cognitive enhancement. We therefore argue that it is necessary for the legislator to explicitly address the issue in the proposed regulations, in order to take a clear position on the topic, as it has been done in the United Kingdom, where the pharmacological neuroenhancers have been explicitly excluded from the regulation. If pharmacological neuroenhancers are going to be considered neurotechnologies, then new law proposals should seek harmonization with the already existing legislation regulating pharmacological health and consumer rights (both globally, taking into account international drug laws, and locally, according to each country's internal regulations) and of course, with the whole system of fundamental rights. Finally, we briefly discuss the ethical problem of equitable access to this new type of neurotechnologies (as part of the neurorights) and leave the debate open for new insights from the scientific community on the possible consequences of including (or not) pharmacological neuroenhancers as neurotechnologies for cognitive enhancement in the framework of the ethical and legal debate.

Not so smart? "Smart" drugs increase the level but decrease the quality of cognitive effort

The efficacy of pharmaceutical cognitive enhancers in everyday complex tasks remains to be established. Using the knapsack optimization problem as a stylized representation of difficulty in tasks encountered in daily life, we discover that methylphenidate, dextroamphetamine, and modafinil cause knapsack value attained in the task to diminish significantly compared to placebo, even if the chance of finding the optimal solution (~50%) is not reduced significantly. Effort (decision time and number of steps taken to find a solution) increases significantly, but productivity (quality of effort) decreases significantly. At the same time, productivity differences across participants decrease, even reverse, to the extent that above-average performers end up below average and vice versa. The latter can be attributed to increased randomness of solution strategies. Our findings suggest that "smart drugs" increase motivation, but a reduction in quality of effort, crucial to solve complex problems, annuls this effect.

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.

Can placebo or nocebo pills improve or impair cognition performance?

OBJECTIVE

Although the placebo effect is well known to affect many behaviors, the effects on cognitive performance are less well investigated.

METHODS

In this study, the effects of a placebo and a nocebo manipulation on cognitive performance was investigated in healthy young participants in an unblinded between-subjects study. In addition, the participants were asked about their subjective experience in the placebo and nocebo condition.

RESULTS

The data suggested that the placebo condition induced the feeling of being more attentive and more motivated and the nocebo condition induced a feeling of being less attentive and alert and that they performed less well than normal. However, no placebo or nocebo effects were found on the actual performance on word learning, working memory, Tower of London task, or spatial pattern separation.

CONCLUSIONS

These findings further support the notion that placebo or nocebo effects are not likely to occur in young healthy volunteers. However, other studies suggest that placebo effects can be found in implicit memory tasks and in participants with memory problems. Further placebo/nocebo studies are indicated using different experimental designs and different populations in order to better understand the placebo effect on cognitive performance.

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.

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.

The subcortical and neurochemical organization of the ventral and dorsal attention networks

Attention is a core cognitive function that filters and selects behaviourally relevant information in the environment. The cortical mapping of attentional systems identified two segregated networks that mediate stimulus-driven and goal-driven processes, the Ventral and the Dorsal Attention Networks (VAN, DAN). Deep brain electrophysiological recordings, behavioral data from phylogenetic distant species, and observations from human brain pathologies challenge purely corticocentric models. Here, we used advanced methods of functional alignment applied to resting-state functional connectivity analyses to map the subcortical architecture of the Ventral and Dorsal Attention Networks. Our investigations revealed the involvement of the pulvinar, the superior colliculi, the head of caudate nuclei, and a cluster of brainstem nuclei relevant to both networks. These nuclei are densely connected structural network hubs, as revealed by diffusion-weighted imaging tractography. Their projections establish interrelations with the acetylcholine nicotinic receptor as well as dopamine and serotonin transporters, as demonstrated in a spatial correlation analysis with a normative atlas of neurotransmitter systems. This convergence of functional, structural, and neurochemical evidence provides a comprehensive framework to understand the neural basis of attention across different species and brain diseases.

Autonomy, procedural and substantive: a discussion of the ethics of cognitive enhancement

As cognitive enhancement research advances, important ethical questions regarding individual autonomy and freedom are raised. Advocates of cognitive enhancement frequently adopt a procedural approach to autonomy, arguing that enhancers improve an individual's reasoning capabilities, which are quintessential to being an autonomous agent. On the other hand, critics adopt a more nuanced approach by considering matters of authenticity and self-identity, which go beyond the mere assessment of one's reasoning capacities. Both positions, nevertheless, require further philosophical scrutiny. In this paper, we investigate the ethics of cognitive enhancement through the lenses of political and philosophical arguments about autonomy and freedom. In so doing, we contend that a substantive, relational account of individual autonomy offers a more holistic understanding of the ethical concerns of cognitive enhancement.

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.

Attention neuroenhancement through tDCS or neurofeedback: a randomized, single-blind, controlled trial

Neurofeedback and transcranial Direct Current Stimulation (tDCS) are promising techniques for neuroenhancement of attentional performance. As far as we know no study compared both techniques on attentional performance in healthy participants. We compared tDCS and neurofeedback in a randomized, single-blind, controlled experiment assessing both behavioral (accuracy and time reaction) and electrophysiological (N1, P1, and P3 components) data of participants responding to the Attention Network Task (ANT). Eighty volunteers volunteered for this study. We adopted standard protocols for both techniques, i.e., a Sensorimotor Rhythm (SMR) protocol for neurofeedback and the right DLPFC anodal stimulation for tDCS, applied over nine sessions (two weeks). We did not find significant differences between treatment groups on ANT, neither at the behavioral nor at the electrophysiological levels. However, we found that participants from both neuromodulation groups, irrespective of if active or sham, reported attentional improvements in response to the treatment on a subjective scale. Our study adds another null result to the neuromodulation literature, showing that neurofeedback and tDCS effects are more complex than previously suggested and associated with placebo effect. More studies in neuroenhancement literature are necessary to fully comprehend neuromodulation mechanisms.

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.

Brain augmentation and neuroscience technologies: current applications, challenges, ethics and future prospects

Ever since the dawn of antiquity, people have strived to improve their cognitive abilities. From the advent of the wheel to the development of artificial intelligence, technology has had a profound leverage on civilization. Cognitive enhancement or augmentation of brain functions has become a trending topic both in academic and public debates in improving physical and mental abilities. The last years have seen a plethora of suggestions for boosting cognitive functions and biochemical, physical, and behavioral strategies are being explored in the field of cognitive enhancement. Despite expansion of behavioral and biochemical approaches, various physical strategies are known to boost mental abilities in diseased and healthy individuals. Clinical applications of neuroscience technologies offer alternatives to pharmaceutical approaches and devices for diseases that have been fatal, so far. Importantly, the distinctive aspect of these technologies, which shapes their existing and anticipated participation in brain augmentations, is used to compare and contrast them. As a preview of the next two decades of progress in brain augmentation, this article presents a plausible estimation of the many neuroscience technologies, their virtues, demerits, and applications. The review also focuses on the ethical implications and challenges linked to modern neuroscientific technology. There are times when it looks as if ethics discussions are more concerned with the hypothetical than with the factual. We conclude by providing recommendations for potential future studies and development areas, taking into account future advancements in neuroscience innovation for brain enhancement, analyzing historical patterns, considering neuroethics and looking at other related forecasts.

Striatal dopamine dissociates methylphenidate effects on value-based versus surprise-based reversal learning

Psychostimulants such as methylphenidate are widely used for their cognitive enhancing effects, but there is large variability in the direction and extent of these effects. We tested the hypothesis that methylphenidate enhances or impairs reward/punishment-based reversal learning depending on baseline striatal dopamine levels and corticostriatal gating of reward/punishment-related representations in stimulus-specific sensory cortex. Young healthy adults (N = 100) were scanned with functional magnetic resonance imaging during a reward/punishment reversal learning task, after intake of methylphenidate or the selective D_2/3-receptor antagonist sulpiride. Striatal dopamine synthesis capacity was indexed with [¹⁸F]DOPA positron emission tomography. Methylphenidate improved and sulpiride decreased overall accuracy and response speed. Both drugs boosted reward versus punishment learning signals to a greater degree in participants with higher dopamine synthesis capacity. By contrast, striatal and stimulus-specific sensory surprise signals were boosted in participants with lower dopamine synthesis. These results unravel the mechanisms by which methylphenidate gates both attention and reward learning.

The mechanisms underpinning the variability in methylphenidate’s effects on cognition remain unclear. Here, the authors show that such effects reflect changes in striatal dopamine-related output gating of task-relevant cortical signals, and that these changes depend on baseline dopamine synthesis capacity.

Identifying Determinants of Neuro-Enchancement Substance Use in Students

Abstract. Background: Use of Neuro-Enhancement Substances (NES) such as prescription drugs, illicit drugs, or alcohol to improve cognition, prosocial behavior, and performance is increasing among students. Aims: The study applied a multi-theory, integrated theoretical model to identify motivational and social cognition determinants of NES use among students. Methods: A prospective longitudinal design was adopted with 306 high school (66.8% female; Mage = 17.31 years, SD = 0.93) and 692 university (70.5% female; Mage = 24.97 years, SD = 6.64) students. They completed measures of motivation, social cognition constructs, and planning with respect to studying behavior and NES use. Results: Well-fitting structural equation models indicated the pervasive influence of autonomous motivation, attitudes, subjective norms, and perceived behavioral control for studying, as well as of attitudes, subjective norms, and perceived behavioral control for NES use. Inclusion of past NES use increased explained variance in NES use and attenuated model effects, but the pattern of effects remained. Multi-group analyses indicated consistency in the pattern model effects across high school and university students. Limitations: The study findings might not be generalizable, as student samples were not randomly recruited. Furthermore, NES use only relied on self-report, and its assessment did not consider different NES substances. Finally, there was no assessment of implicit attitudes and habits toward studying and NES use. Conclusions: Findings extend prior literature by demonstrating the integrated guiding view that students’ motivation and beliefs about studying influence their beliefs about and use of NES. Furthermore, the findings provide starting points for interventions targeting the reduction in NES use.

Intelligenzsteigerung durch Neuroenhancement?

Zusammenfassung. Die menschliche Intelligenz gehört zu den bestuntersuchten psychologischen Merkmalen, in denen interindividuelle Differenzen bestehen. Die mehr als 100jährige Forschungsgeschichte hat einen hoch belastbaren Wissensstand hervorgebracht; dieser umfasst die Definition, die Psychometrie, die (ontogenetische) Entwicklung, die Struktur, die Vorhersagekraft für real-life-Variablen, das Wissen über elementar-kognitive, verhaltensgenetische und neurobiologische Grundlagen der Intelligenz, u.v.m. Jüngst steht zudem die Frage des ‚enhancements‘ der Intelligenz im Fokus, eine Frage, die nicht zuletzt durch die aktuelle philosophische Strömung des Transhumanismus stark an Bedeutung gewinnt. Der Transhumanismus nimmt eine substanzielle Erhöhung (enhancement) von Fähigkeiten und anderen (auch) psychologischen Eigenschaften des Menschen ins Zentrum und postuliert, dass ein soziokultureller Fortschritt – und letztlich das Überlegen des Homo Sapiens und unseres Planeten – erst durch technologischen Fortschritt ermöglicht werde. Viele Transhumanisten stellen eine substanzielle Steigerung der Intelligenz in den Vordergrund, die primär durch (neuro–)‌technologische und pharmakologische Maßnahmen zu bewerkstelligen seien. Diese Debatten sind jedoch oft gekennzeichnet durch übertrieben optimistische Annahmen der Möglichkeiten moderner neurowissenschaftlicher Methoden bei gleichzeitiger Vernachlässigung der potenziellen negativen Folgen für das Individuum, für die Gesellschaften und insgesamt für unsere Spezies. Im gegenständlichen Überblicksbeitrag werden behaviorale, neuroelektrische und pharmakologische Methoden im Hinblick auf ihr aktuelles Potenzial einer Steigerung der individuellen Intelligenz analysiert. Die zwischenzeitlich zu diesen Fragen vorliegenden experimentellen Studien, sowie verfügbare Metaanalysen lassen allerdings den Schluss zu, dass bislang keine der gegenwärtig verfügbaren Methoden das Potenzial haben, die individuelle Intelligenz substanziell zu steigern. Und selbst falls solche möglicherweise in absehbarer Zeit zur Verfügung stünden, müssen zuvor sowohl individuelle als auch gesellschaftliche (negative) Konsequenzen einer kritischen Analyse unterzogen werden. Diese sind Gegenstand einer abschließenden Diskussion.

Sex differences in neurobehavioral consequences of methamphetamine exposure in adult mice

RATIONALE

Recreational and medical use of stimulants is increasing, and their use may increase susceptibility to aging and promote neurobehavioral impairments. The long-term consequences of these psychostimulants and how they interact with age have not been fully studied.

OBJECTIVES

Our study investigated whether chronic exposure to the prototypical psychostimulant, methamphetamine (METH), at doses designed to emulate human therapeutic dosing, would confer a pro-oxidizing redox shift promoting long-lasting neurobehavioral impairments.

METHODS

Groups of 4-month-old male and female C57BL/6 J mice were administered non-contingent intraperitoneal injections of either saline or METH (1.4 mg/kg) twice a day for 4 weeks. Mice were randomly assigned to one experimental group: (i) short-term cognitive assessments (at 5 months), (ii) long-term cognitive assessments (at 9.5 months), and (ii) longitudinal motor assessments (at 5, 7, and 9 months). Brain regions were assessed for oxidative stress and markers of neurotoxicity after behavior testing.

RESULTS

Chronic METH exposure induced short-term effects on associative memory, gait speed, dopamine (DA) signaling, astrogliosis in females, and spatial learning and memory, balance, DA signaling, and excitotoxicity in males. There were no long-term effects of chronic METH on cognition; however, it decreased markers of excitotoxicity in the striatum and exacerbated age-associated motor impairments in males.

CONCLUSION

In conclusion, cognitive and motor functions were differentially and sex-dependently affected by METH exposure, and oxidative stress did not seem to play a role in the observed behavioral outcomes. Future studies are necessary to continue exploring the long-term neurobehavioral consequences of drug use in both sexes and the relationship between aging and drugs.

Human enhancement and personality: A new approach towards investigating their relationship

With the rise of new technologies, also human enhancement is widely discussed. Especially the philosophical movement "transhumanism" urges for creating "better humans" by applying different enhancement methods, namely: pharmacological, current-based, and genetic enhancement as well as mind uploading. While the first three aim at enhancing human characteristics, mind uploading promises immortality by uploading one's brain onto an external storage medium. In the present study, we adapted the method of divergent thinking tasks to assess individuals' assumptions about enhancement methods. These were rated regarding their negativity/positivity and societal-/individual-orientation and then tested whether they are predicted by basic human values and selected personality traits. While individuals' values were not related to their assumptions about enhancement, openness predicted more negative assumptions about most enhancement methods, and a higher intellect predicted more societal-oriented assumptions about genetic enhancement. Furthermore, higher grandiose narcissism predicted more negative assumptions about current-based enhancement and higher psychopathic tendencies predicted more positive assumptions about genetic enhancement. Additionally, higher Machiavellianism predicted more individual-oriented assumptions about pharmacological and current-based enhancement. However, all relationships were of small effect size. We urge for further psychological research in this increasingly relevant field.

Beliefs About Medicines Predict Side-Effects of Placebo Modafinil

BACKGROUND

Patients receiving placebo in clinical trials often report side-effects (nocebo effects), but contributing factors are still poorly understood.

PURPOSE

Using a sham trial of the cognition-enhancing "smart pill" Modafinil we tested whether medication beliefs and other psychological factors predicted detection and attribution of symptoms as side-effects to placebo.

METHODS

Healthy students (n = 201) completed measures assessing beliefs about medication, perceived sensitivity to medicines, negative affectivity, somatization, and body awareness; 66 were then randomized to receive Deceptive Placebo (told Modafinil-given placebo, 67 to Open Placebo (told placebo-given placebo, and 68 to No Placebo. Memory and attention tasks assessed cognitive enhancement. Nocebo effects were assessed by symptom checklist.

RESULTS

More symptoms were reported in the Deceptive Placebo condition (M = 2.65; SD = 2.27) than Open Placebo (M = 1.92; SD = 2.24; Mann-Whitney U = 1,654, z = 2.30, p = .022) or No Placebo (M = 1.68; SD = 1.75, Mann-Whitney U = 1,640, z = 2.74, p = .006). Participants were more likely to attribute symptoms to Modafinil side-effects if they believed pharmaceuticals to be generally harmful (incidence rate ratio [IRR] = 1.70, p = .019), had higher perceived sensitivity to medicines (IRR = 1.68, p = .011), stronger concerns about Modafinil (IRR = 2.10, p < .001), and higher negative affectivity (IRR = 2.37, p < .001).

CONCLUSIONS

Beliefs about medication are potentially modifiable predictors of the nocebo effect. These findings provide insight into side-effect reports to placebo and, potentially, active treatment.

Use and misuse of prescription stimulants by university students: a cross-sectional survey in the french-speaking community of Belgium, 2018

Background

Misuse of prescription stimulants (PS) has been reported among students to enhance academic performance in Flanders (Belgium). However, PS misuse among students in the French-speaking community is unknown. The main purpose of the study was to estimate the prevalence of medical use and misuse of PS by university students in the French-speaking community (Belgium), and to investigate the reasons and sources associated with PS misuse.

Methods

A cross-sectional online survey was performed in 2018. All university students 18 years and older were invited to participate and asked about PS use, including medical (i.e., used for therapeutic purposes) and nonmedical reasons and sources of PS.

Results

In total, 12 144 students participated in the survey (median age = 21 years, 65.5% female). The estimated prevalence of PS use was 6.9% (ever use) and 5.5% (past-year). Among ever users, 34.7% were classified as medical users and 65.3% as misusers. Lifetime prevalence of misuse was estimated at 4.5%. The most common reason for medical use was treatment of attention disorder (85.9%). Reasons for misuse were mainly to improve concentration (76.1%) or to stay awake and study longer (50.7%). Friends or acquaintances inside the student community and general practitioners were the main sources of PS for misuse (41.5% and 23.5%, respectively).

Conclusions

This study found that rates of misuse of PS in French-speaking universities in Belgium were in line with studies conducted in Flanders and Europe. Academic institutions can use these results to tailor their drug prevention campaigns.

Influence of modafinil on early ejaculation - Results from a double-blind randomized clinical trial

BACKGROUND

For men, early ejaculation is a serious health concern. Here, we tested the influence of modafinil (Profinil®) on early ejaculation. To this end, we performed a double-blind randomized clinical trial among men with early ejaculation.

METHODS

A total of 46 men with early ejaculation (mean age: 37.35 years) and in stable marital relationships with regular weekly penile-vaginal intercourse were randomly assigned either to the modafinil (100 mg) or to the placebo condition. Compounds were taken about 4-6h before intended penile-vaginal intercourse. At baseline and four weeks later at the end of the study, participants completed a series of self-rating questionnaires covering early ejaculation. Female partners also rated their male partners' early ejaculation profile.

RESULTS

Dimensions of early ejaculation improved over time, but only so in the modafinil condition, while no improvements were observed in the placebo condition.

CONCLUSIONS

Among male adults in stable marital relationships with regular weekly penile-vaginal intercourse modafinil improved dimensions of early ejaculation, always compared to placebo. Given the strong effect of modafinil on cognitive-executive processes, it is conceivable, that modafinil acted both via physiological and cognitive-executive pathways.

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.

Cognitive profiling and proteomic analysis of the modafinil analogue S-CE-123 in experienced aged rats

The lack of novel cognitive enhancer drugs in the clinic highlights the prediction problems of animal assays. The objective of the current study was to test a putative cognitive enhancer in a rodent cognitive test system with improved translational validity and clinical predictivity. Cognitive profiling was complemented with post mortem proteomic analysis. Twenty-seven male Lister Hooded rats (26 months old) having learned several cognitive tasks were subchronically treated with S-CE-123 (CE-123) in a randomized blind experiment. Rats were sacrificed after the last behavioural procedure and plasma and brains were collected. A label-free quantification approach was used to characterize proteomic changes in the synaptosomal fraction of the prefrontal cortex. CE-123 markedly enhanced motivation which resulted in superior performance in a new-to-learn operant discrimination task and in a cooperation assay of social cognition, and mildly increased impulsivity. The compound did not affect attention, spatial and motor learning. Proteomic quantification revealed 182 protein groups significantly different between treatment groups containing several proteins associated with aging and neurodegeneration. Bioinformatic analysis showed the most relevant clusters delineating synaptic vesicle recycling, synapse organisation and antioxidant activity. The cognitive profile of CE-123 mapped by the test system resembles that of modafinil in the clinic showing the translational validity of the test system. The findings of modulated synaptic systems are paralleling behavioral results and are in line with previous evidence for the role of altered synaptosomal protein groups in mechanisms of cognitive function.

The case for biotechnological exceptionalism

Do biomedical interventions raise special moral concerns? A rising number of prominent authors claim that at least in the case of biomedical enhancement they do not. Treating biomedical enhancements different from non-biomedical ones, they claim, amounts to unjustified biomedical exceptionalism. This article vindicates the familiar thesis that biomedical enhancement raises specific concerns. Taking a close look at the argumentative strategy against biomedical exceptionalism and provides counterexamples showing that the biomedical mode of interventions raises concerns not relevant otherwise. In particular, biomedical interventions throughout raise concerns of informed consent, which only rarely turn up in comparable non-biomedical interventions.

A State-of-the-Art Review on the Use of Modafinil as A Performance-enhancing Drug in the Context of Military Operationality

INTRODUCTION

Modafinil is an eugeroic drug that has been examined to maintain or recover wakefulness, alertness, and cognitive performance when sleep deprived. In a nonmilitary context, the use of modafinil as a nootropic or smart drug, i.e., to improve cognitive performance without being sleep deprived, increases. Although cognitive performance is receiving more explicit attention in a military context, research into the impact of modafinil as a smart drug in function of operationality is lacking. Therefore, the current review aimed at presenting a current state-of-the-art and research agenda on modafinil as a smart drug. Beside the question whether modafinil has an effect or not on cognitive performance, we examined four research questions based on the knowledge on modafinil in sleep-deprived subjects: (1) Is there a difference between the effect of modafinil as a smart drug when administered in repeated doses versus one single dose?; (2) Is the effect of modafinil as a smart drug dose-dependent?; (3) Are there individual-related and/or task-related impact factors?; and (4) What are the reported mental and/or somatic side effects of modafinil as a smart drug?

METHOD

We conducted a systematic search of the literature in the databases PubMed, Web of Science, and Scopus, using the search terms "Modafinil" and "Cognitive enhance*" in combination with specific terms related to the research questions. The inclusion criteria were studies on healthy human subjects with quantifiable cognitive outcome based on cognitive tasks.

RESULTS

We found no literature on the impact of a repeated intake of modafinil as a smart drug, although, in users, intake occurs on a regular basis. Moreover, although modafinil was initially said to comprise no risk for abuse, there are now indications that modafinil works on the same neurobiological mechanisms as other addictive stimulants. There is also no thorough research into a potential risk for overconfidence, whereas this risk was identified in sleep-deprived subjects. Furthermore, eventual enhancing effects were beneficial only in persons with an initial lower performance level and/or performing more difficult tasks and modafinil has an adverse effect when used under time pressure and may negatively impact physical performance. Finally, time-on-task may interact with the dose taken.

DISCUSSION

The use of modafinil as a smart drug should be examined in function of different military profiles considering their individual performance level and the task characteristics in terms of cognitive demands, physical demands, and sleep availability. It is not yet clear to what extent an improvement in one component (e.g., cognitive performance) may negatively affect another component (e.g., physical performance). Moreover, potential risks for abuse and overconfidence in both regular and occasional intake should be thoroughly investigated to depict the trade-off between user benefits and unwanted side effects. We identified that there is a current risk to the field, as this trade-off has been deemed acceptable for sleep-deprived subjects (considering the risk of sleep deprivation to performance) but this reasoning cannot and should not be readily transposed to non-sleep-deprived individuals. We thus conclude against the use of modafinil as a cognitive enhancer in military contexts that do not involve sleep deprivation.

Protocols for cognitive enhancement. A user manual for Brain Health Services-part 5 of 6

Cognitive complaints in the absence of objective cognitive impairment, observed in patients with subjective cognitive decline (SCD), are common in old age. The first step to postpone cognitive decline is to use techniques known to improve cognition, i.e., cognitive enhancement techniques.We aimed to provide clinical recommendations to improve cognitive performance in cognitively unimpaired individuals, by using cognitive, mental, or physical training (CMPT), non-invasive brain stimulations (NIBS), drugs, or nutrients. We made a systematic review of CMPT studies based on the GRADE method rating the strength of evidence.CMPT have clinically relevant effects on cognitive and non-cognitive outcomes. The quality of evidence supporting the improvement of outcomes following a CMPT was high for metamemory; moderate for executive functions, attention, global cognition, and generalization in daily life; and low for objective memory, subjective memory, motivation, mood, and quality of life, as well as a transfer to other cognitive functions. Regarding specific interventions, CMPT based on repeated practice (e.g., video games or mindfulness, but not physical training) improved attention and executive functions significantly, while CMPT based on strategic learning significantly improved objective memory.We found encouraging evidence supporting the potential effect of NIBS in improving memory performance, and reducing the perception of self-perceived memory decline in SCD. Yet, the high heterogeneity of stimulation protocols in the different studies prevent the issuing of clear-cut recommendations for implementation in a clinical setting. No conclusive argument was found to recommend any of the main pharmacological cognitive enhancement drugs ("smart drugs", acetylcholinesterase inhibitors, memantine, antidepressant) or herbal extracts (Panax ginseng, Gingko biloba, and Bacopa monnieri) in people without cognitive impairment.Altogether, this systematic review provides evidence for CMPT to improve cognition, encouraging results for NIBS although more studies are needed, while it does not support the use of drugs or nutrients.

Memory enhancement with stimulants: Differential neural effects of methylphenidate, modafinil, and caffeine. A pilot study

Human memory is susceptible to manipulation in many respects. While consolidation is well known to be prone to disruption, there is also growing evidence for the enhancement of memory function. Beside cognitive strategies and mnemonic training, the use of stimulants may improve memory processing in healthy adults. In this single-dose, double-blind, within-subject, randomized, placebo-controlled pilot study, 20 mg methylphenidate (N = 13) or 200 mg modafinil (N = 12) or 200 mg caffeine (N = 14) were administrated to in total 39 healthy participants while performing a declarative memory task. Each participant received only one substance and functional magnetic resonance imaging (fMRI) was used to assess drug-dependent memory effects of the substance for encoding and recognition compared to task-related activation under placebo. While methylphenidate showed some behavioral effect regarding memory recall performance, on the neural level, methylphenidate-dependent deactivations were found in fronto-parietal and temporal regions during recognition of previously learned words. No BOLD alterations were seen during encoding. Caffeine led to deactivations in the precentral gyrus during encoding whereas modafinil did not show any BOLD signal alterations at all. These results should be interpreted with caution since this a pilot study with several limitations, most importantly the small number of participants per group. However, our main finding of task-related deactivations may point to a drug-dependent increase of efficiency in physiological response to memory processing.

Neuroenhancement: State of the Art and Future Perspectives

Pharmacological neuroenhancement refers to the non-medical use of prescription drugs, alcohol, illegal drugs, or the so-called soft enhancers for the purpose of improving cognition, mood, pro-social behavior, or work and academic performance. This phenomenon is undoubtedly more frequent than previously supposed especially amongst university students. The aim of the present paper was to carefully review and comment on the available literature on neuroenhancement, according to Prisma guidelines. The results showed a great use of all prescribed drugs (benzodiazepines, antidepressants, antipsychotics, nootropic compounds, and especially stimulants) as neuroenhancers amongst healthy subjects, although probably the real prevalence is underestimated. The use of illicit drugs and soft enhancers is similarly quite common. Data on the improvement of cognition by other compounds, such as oxytocin and pheromones, or non-pharmacological techniques, specifically deep brain stimulation and transcranial magnetic stimulation, are still limited. In any case, if it is true that human beings are embedded by the desire to overcome the limits of their intrinsic nature, neuroenhancement practices put into question the concept of authenticity. Therefore, the problem appears quite complex and requires to be deepened and analyzed with no prejudice, although within an ethical conceptual frame.

Stimulating meditation: a pre-registered randomised controlled experiment combining a single dose of the cognitive enhancer, modafinil, with brief mindfulness training

BACKGROUND

Mindfulness-meditation has a variety of benefits on well-being. However, individuals with primary attentional impairments (e.g. attention deficit disorder) or attentional symptoms secondary to anxiety, depression or addiction, may be less likely to benefit, and require additional mindfulness-augmenting strategies.

AIMS

To determine whether a single dose of the cognitive enhancer, modafinil, acutely increases subjective and behavioural indices of mindfulness, and augments brief mindfulness training.

METHODS

A randomised, double-blind, placebo-controlled, 2 (drug: placebo, modafinil) × 2 (strategy: mindfulness, relaxation control) experiment was conducted. Seventy-nine meditation-naïve participants were assigned to: placebo-relaxation, placebo-mindfulness, modafinil-relaxation or modafinil-mindfulness. Pre-drug, post-drug and post-strategy state mindfulness, affect and autonomic activity, along with post-strategy sustained attention and mind-wandering were assessed within a single lab session. After the session, participants were instructed to practice their assigned behavioural strategy daily for one week, with no further drug administration, after which, follow-up measures were taken.

RESULTS

As predicted, modafinil acutely increased state mindfulness and improved sustained attention. Differential acute strategy effects were found following mindfulness on autonomic activity but not state mindfulness. There were no strategy or drug effects on mind-wandering. However, exploratory analyses indicated that participants receiving modafinil engaged in more strategy practice across strategy conditions during follow-up.

CONCLUSIONS

Modafinil acutely mimicked the effects of brief mindfulness training on state mindfulness but did not enhance the effects of this training. Limitations of the current study, and recommendations for future research examining modafinil as an adjunct to mindfulness- (or relaxation-) based treatments are discussed.

Towards an understanding of how stress and resources affect the nonmedical use of prescription drugs for performance enhancement among employees

Based on assumptions of the Job Demands-Resources model, we investigated employees’ willingness to use prescription drugs such as methylphenidate and modafinil for nonmedical purposes to enhance their cognitive functioning as a response to strain (i.e., perceived stress) that is induced by job demands (e.g., overtime, emotional demands, shift work, leadership responsibility). We also examined the direct and moderating effects of resources (e.g., emotional stability, social and instrumental social support) in this process. We utilized data from a representative survey of employees in Germany (N = 6454) encompassing various job demands and resources, levels of perceived stress, and willingness to use nonmedical drugs for performance enhancement purposes. By using Structural Equation Models, we found that job demands (such as overtime and emotional demands) and a scarcity of resources (such as emotional stability) increased strain, consequently directly and indirectly increasing the willingness to use prescription drugs for cognitive enhancement. Moreover, emotional stability reduced the effect of certain demands on strain. These results delivered new insights into mechanisms behind nonmedical prescription drug use that can be used to prevent such behaviour and potential negative health consequences.

Social Justice Theories as the Basis for Public Policy on Psychopharmacological Cognitive Enhancement

Psychopharmacological cognitive enhancements could lead to a higher quality of life of healthy individuals with lower cognitive capacities, but the current regulatory framework does not seem to enable access to this group. This article discusses why Sen’s Capability Approach could open up such access, while two other modern social justice theories – utilitarianism and Rawls’ Justice as Fairness – could not. In short, the utilitarian approach is proven to be inadequate, due to practical reasons and having a low chance of real-world success. Rawls’ Justice as Fairness seems to be problematic because of conflicting stances that follow from his First Principle of Justice. The Capability Approach has the greatest chance of success in the context of these substances, because of arguments that can be identified under the banners of agency/self-respect and the way the public views those who take the capability path out of their poor situation. The article also discusses general and practical problems with psychopharmacological cognitive enhancement that should be addressed when writing new policy on this topic.

Neuroenhancement in French and Romanian University Students, Motivations and Associated Factors

This cross-sectional study aimed to determine the use of neuroenhancers, the motivations and factors associated with their use in French and Romanian university students. Students from two universities in France (Rouen and Opal Coast University) and one in Romania (Cluj-Napoca) were asked to complete a self-administered anonymous questionnaire, either online or on paper, about the use of three different categories of substance: Prescription drugs (methylphenidate, modafinil, and beta-blockers), drugs of abuse (alcohol, cannabis, cocaine, and amphetamines), and soft enhancers (coffee, vitamins, caffeine tablets, and energy drinks). In total, 1110 students were included: The users were 2.2% for prescription drugs, 4.3% for drugs of abuse, and 55.0% for soft enhancers. Students used neuroenhancement to stay awake for study (69.3%), to improve concentration (55.5%), to decrease stress (40.9%), and to improve memory (39.6%). Neuroenhancement was considered to meet expectations by 74.4% of users. The factors associated with the use of drugs of abuse were frequent binge drinking (Adjusted Odds Ratio-AOR: 6.49 [95% CI: 2.53-16.6]), smoking (AOR: 5.50 [95% CI: 2.98-10.14]), having a student job (AOR: 2.42 [95% CI 1.13-5.17]), and being male (AOR: 2.23 [95% CI:1.21-4.11]). No significant associations with eating disorders were detected for any of the three categories of substances. University students reported neuroenhancement with prescription drugs, drugs of abuse, and mainly soft enhancers. These substances were used mainly to increase the waking hours. Educational programs in universities seem to be required in order to increase student awareness of the problems caused by neuroenhancements, and to decrease the associated risks by changing students' attitudes and beliefs.

Cognitive Enhancement: Unanswered Questions About Human Psychology and Social Behavior

Stimulant drugs, transcranial magnetic stimulation, brain-computer interfaces, and even genetic modifications are all discussed as forms of potential cognitive enhancement. Cognitive enhancement can be conceived as a benefit-seeking strategy used by healthy individuals to enhance cognitive abilities such as learning, memory, attention, or vigilance. This phenomenon is hotly debated in the public, professional, and scientific literature. Many of the statements favoring cognitive enhancement (e.g., related to greater productivity and autonomy) or opposing it (e.g., related to health-risks and social expectations) rely on claims about human welfare and human flourishing. But with real-world evidence from the social and psychological sciences often missing to support (or invalidate) these claims, the debate about cognitive enhancement is stalled. In this paper, we describe a set of crucial debated questions about psychological and social aspects of cognitive enhancement (e.g., intrinsic motivation, well-being) and explain why they are of fundamental importance to address in the cognitive enhancement debate and in future research. We propose studies targeting social and psychological outcomes associated with cognitive enhancers (e.g., stigmatization, burnout, mental well-being, work motivation). We also voice a call for scientific evidence, inclusive of but not limited to biological health outcomes, to thoroughly assess the impact of enhancement. This evidence is needed to engage in empirically informed policymaking, as well as to promote the mental and physical health of users and non-users of enhancement.

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

INTRODUCTION

Cognitive enhancers (CEs), also known as "smart drugs", "study aids" or "nootropics" are a cause of concern. Recent research studies investigated the use of CEs being taken as study aids by university students. This manuscript provides an overview of popular CEs, focusing on a range of drugs/substances (e.g., prescription CEs including amphetamine salt mixtures, methylphenidate, modafinil and piracetam; and non-prescription CEs including caffeine, cobalamin (vitamin B12), guarana, pyridoxine (vitamin B6) and vinpocetine) that have emerged as being misused. The diverted non-prescription use of these molecules and the related potential for dependence and/or addiction is being reported. It has been demonstrated that healthy students (i.e., those without any diagnosed mental disorders) are increasingly using drugs such as methylphenidate, a mixture of dextroamphetamine/amphetamine, and modafinil, for the purpose of increasing their alertness, concentration or memory.

AIM

To investigate the level of knowledge, perception and impact of the use of a range of CEs within Higher Education Institutions.

METHODOLOGY

A systematic review was conducted in adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Whilst 1400 studies were identified within this study through a variety of electronic databases (e.g., 520 through PubMed, 490 through Science Direct and 390 through Scopus), 48 papers were deemed relevant and were included in this review.

RESULTS

The most popular molecules identified here included the stimulant CEs, e.g., methylphenidate, modafinil, amphetamine salt mixtures and caffeine-related compounds; stimulant CEs' intake was more prevalent among males than females; drugs were largely obtained from friends and family, as well as via the Internet. It is therefore suggested that CEs are increasingly being used among healthy individuals, mainly students without any diagnosed cognitive disorders, to increase their alertness, concentration, or memory, in the belief that these CEs will improve their performance during examinations or when studying. The impact of stimulant CEs may include tolerance, dependence and/or somatic (e.g., cardiovascular; neurological) complications.

DISCUSSION

The availability of CEs for non-medical indications in different countries is influenced by a range of factors including legal, social and ethical factors. Considering the risk factors and motivations that encourage university students to use CE drugs, it is essential to raise awareness about CE-related harms, counteract myths regarding "safe" CE use and address cognitive enhancement in an early stage during education as a preventative public health measure.

Cognitive enhancement effects of stimulants: a randomized controlled trial testing methylphenidate, modafinil, and caffeine

RATIONAL

At all times humans have made attempts to improve their cognitive abilities by different means, among others, with the use of stimulants. Widely available stimulants such as caffeine, but also prescription substances such as methylphenidate and modafinil, are being used by healthy individuals to enhance cognitive performance.

OBJECTIVES

There is a lack of knowledge on the effects of prescription stimulants when taken by healthy individuals (as compared with patients) and especially on the effects of different substances across different cognitive domains.

METHODS

We conducted a pilot study with three arms in which male participants received placebo and one of three stimulants (caffeine, methylphenidate, modafinil) and assessed cognitive performance with a test battery that captures various cognitive domains.

RESULTS

Our study showed some moderate effects of the three stimulants tested. Methylphenidate had positive effects on self-reported fatigue as well as on declarative memory 24 hours after learning; caffeine had a positive effect on sustained attention; there was no significant effect of modafinil in any of the instruments of our test battery. All stimulants were well tolerated, and no trade-off negative effects on other cognitive domains were found.

CONCLUSIONS

The few observed significant positive effects of the tested stimulants were domain-specific and of rather low magnitude. The results can inform the use of stimulants for cognitive enhancement purposes as well as direct further research to investigate the effects of stimulants on specific cognitive domains that seem most promising, possibly by using tasks that are more demanding.

Understanding the relationship between safety beliefs and knowledge for cognitive enhancers in UK university students

BACKGROUND

Cognitive enhancers (CE) are prescription drugs taken, either without a prescription or at a dose exceeding that which is prescribed, to improve cognitive functions such as concentration, vigilance or memory. Previous research suggests that users believe the drugs to be safer than non-users and that they have sufficient knowledge to judge safety. However, to date no research has compared the information sources used and safety knowledge of users and non-users.

OBJECTIVES

This study compared users and non-users of CE in terms of i) their sources of knowledge about the safety of CE and ii) the accuracy of their knowledge of possible adverse effects of a typical cognitive enhancer (modafinil); and iii) how the accuracy of knowledge relates to their safety beliefs.

METHODS

Students (N = 148) from King's College London (UK) completed an anonymous online survey assessing safety beliefs, sources of knowledge and knowledge of the safety of modafinil; and indicated whether they used CE, and, if so, which drug(s).

RESULTS

The belief that the drugs are safe was greater in users than non-users. However, both groups used comparable information sources and have similar, relatively poor drug safety knowledge. Furthermore, despite users more strongly believing in the safety of CE there was no relationship between their beliefs and knowledge, in contrast to non-users who did show correlations between beliefs and knowledge.

CONCLUSION

These data suggest that the differences in safety beliefs about CE between users and non-users do not stem from use of different information sources or more accurate safety knowledge.