Neuro-Enhancement: Gehirndoping

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

Background

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

Methods

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

Results

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

Conclusion

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

How cognitive enhancement can change our duties

This theoretical paper draws the scientific community's attention to how pharmacological cognitive enhancement may impact on society and law. Namely, if safe, reliable, and effective techniques to enhance mental performance are eventually developed, then this may under some circumstances impose new duties onto people in high-responsibility professions-e.g., surgeons or pilots-to use such substances to minimize risks of adverse outcomes or to increase the likelihood of good outcomes. By discussing this topic, we also hope to encourage scientists to bring their expertise to bear on this current public debate.

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

Background

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

Study aim

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

Method

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

Results

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

Conclusions

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

Memory and self-neuroscientific landscapes

Relations between memory and the self are framed from a number of perspectives-developmental aspects, forms of memory, interrelations between memory and the brain, and interactions between the environment and memory. The self is seen as dividable into more rudimentary and more advanced aspects. Special emphasis is laid on memory systems and within them on episodic autobiographical memory which is seen as a pure human form of memory that is dependent on a proper ontogenetic development and shaped by the social environment, including culture. Self and episodic autobiographical memory are seen as interlocked in their development and later manifestation. Aside from content-based aspects of memory, time-based aspects are seen along two lines-the division between short-term and long-term memory and anterograde-future-oriented-and retrograde-past-oriented memory. The state dependency of episodic autobiographical is stressed and implications of it-for example, with respect to the occurrence of false memories and forensic aspects-are outlined. For the brain level, structural networks for encoding, consolidation, storage, and retrieval are discussed both by referring to patient data and to data obtained in normal participants with functional brain imaging methods. It is elaborated why descriptions from patients with functional or dissociative amnesia are particularly apt to demonstrate the facets in which memory, self, and personal temporality are interwoven.

Cognitive-enhancing substance use at German universities: frequency, reasons and gender differences

BACKGROUND

The purpose of this study was to give an overview whether German students regularly use stimulants for enhancing their academic performance. Reasons associated with the use of these substances were explored. Moreover, gender differences were analyzed.

METHODS

A cross-sectional survey study was performed analyzing a random sample of 1,053 students of different fields of study in Germany. Students were asked to complete an anonymous self-administered web-based survey containing questions on cognitive performance-enhancing substance use. We used statistical analyses, e.g. non-parametric tests to evaluate the data of our questionnaire.

RESULTS

Among 1,053 students, 61 % responded to our questionnaire. The average age was M = 24.58; 635 participants were female and 418 were male students. Total 1-13 % of the participating students have taken prescription stimulants (e.g. modafinil) or illicit drugs (e.g. cannabis) at least once in their lifetime. The most common reasons for taking stimulants were to support concentration, to relax and to increase alertness. We found significant gender differences with regard to frequency and reason for using performance-enhancing substances.

CONCLUSIONS

Our study results give an overview about the actual situation on frequency and reasons for taking performance-enhancing substances. Departments of Public Health should address this issue in national health debates and discussions. Based on our study findings health education programmes should be developed.

[Lifestyle and cognition: what do we know from the aging and neurodegenerative brain?]

Epidemiological studies demonstrated positive effects of continuous physical activity and balanced diet on cardiovascular fitness. In chronic neurodegenerative disorders, e.g. Parkinson's disease and Alzheimer's disease, physical activity has become a successful supportive symptomatic therapy. However, it has become evident that physical activity not only improves motor symptoms but also has high impact on cognition in both (elderly) healthy brain and neurodegenerative alterations in the CNS. Nutrition also has been reported to exert positive effects on brain function.Animal studies indicate an increased endogenous plasticity as the underlying mechanism in terms of activation of neuronal precursor cells in different brain areas, leading to improved brain function.First experimental studies in humans also show that physical activity and balanced nutrition increase the release of neurotrophic factors in the brain, increase the volume of grey matter in learning- and memory-associated brain regions and improve cognitive function. This phenomenon opens up noninvasive causal therapeutic options in neurodegenerative disorders and during aging-associated cognitive decline by inducing changes in lifestyle. This option could provide a socioeconomically and ethically reasonable treatment for neurodegenerative disorders.The presented article summarizes the current knowledge from animal experiments and studies in humans. It provides an overview of potential cellular and molecular candidate mechanisms and discusses novel translational clinical studies and first clinical applications.

Dimebon enhances hippocampus-dependent learning in both appetitive and inhibitory memory tasks in mice

Pre-clinical and clinical studies on dimebon (dimebolin or latrepirdine) have demonstrated its use as a cognitive enhancer. Here, we show that dimebon administered to 3-month-old C57BL6N mice 15 min prior to training in both appetitive and inhibitory learning tasks via repeated (0.1 mg/kg) and acute (0.5 mg/kg) i.p. injections, respectively, increases memory scores. Acute treatment with dimebon was found to enhance inhibitory learning, as also shown in the step-down avoidance paradigm in 7-month-old mice. Bolus administration of dimebon did not affect the animals' locomotion, exploration or anxiety-like behaviour, with the exception of exploratory behaviour in older mice in the novel cage test. In a model of appetitive learning, a spatial version of the Y-maze, dimebon increased the rate of correct choices and decreased the latency of accessing a water reward after water deprivation, and increased the duration of drinking behaviour during training/testing procedures. Repeated treatment with dimebon did not alter the behaviours in other tests or water consumption. Acute treatment of water-deprived and non-water-deprived mice with dimebon also did not affect their water intake. Our data suggest that dimebon enhances hippocampus-dependent learning in both appetitive and inhibitory tasks in mice.