Pharmacological neuroenhancement and the ability to recover from stress - a representative cross-sectional survey among the German population

Neurobiology and systems biology of stress resilience

Stress resilience is the phenomenon that some people maintain their mental health despite exposure to adversity or show only temporary impairments followed by quick recovery. Resilience research attempts to unravel the factors and mechanisms that make resilience possible and to harness its insights for the development of preventative interventions in individuals at risk for acquiring stress-related dysfunctions. Biological resilience research has been lagging behind the psychological and social sciences but has seen a massive surge in recent years. At the same time, progress in this field has been hampered by methodological challenges related to finding suitable operationalizations and study designs, replicating findings, and modeling resilience in animals. We embed a review of behavioral, neuroimaging, neurobiological, and systems biological findings in adults in a critical methods discussion. We find preliminary evidence that hippocampus-based pattern separation and prefrontal-based cognitive control functions protect against the development of pathological fears in the aftermath of singular, event-type stressors [as found in fear-related disorders, including simpler forms of posttraumatic stress disorder (PTSD)] by facilitating the perception of safety. Reward system-based pursuit and savoring of positive reinforcers appear to protect against the development of more generalized dysfunctions of the anxious-depressive spectrum resulting from more severe or longer-lasting stressors (as in depression, generalized or comorbid anxiety, or severe PTSD). Links between preserved functioning of these neural systems under stress and neuroplasticity, immunoregulation, gut microbiome composition, and integrity of the gut barrier and the blood-brain barrier are beginning to emerge. On this basis, avenues for biological interventions are pointed out.

Neuroenhancement and mental health in students from four faculties - a cross-sectional questionnaire study

Background

Students face great challenges at the beginning of and during their studies. Competitive experience, exam anxiety, and especially the new performance requirements often cause test anxiety and stressful experiences. The extent of substance use in terms of neuroenhancement (NE) is unclear. Evidence shows associations between NE, increased stress levels, and mental health.

Objectives

We aim to determine the prevalence of NE and alcohol and tobacco use among college students. We also investigate the associations between NE and ADHD, anxiety, depression, and stress experience.

Methods

In spring 2021, an anonymous online cross-sectional survey was conducted among students of medicine, dentistry, business economics, and business informatics in Würzburg. The survey included the instruments ASRS (ADHD), PSS-10 (stress), PHQ-4 (depression and anxiety), and AUDIT-C (alcohol comsumption), as well as questions about consumption patterns, prior knowledge, and reasons for NE.

Results

Of the 5564 students who were invited to participate, 1010 completed the questionnaire (18.2%). Of these, 12.4% indicated NE for the studied period. NE was used in particular during preparations for exams, to enhance performance, and/or to regulate emotions, most commonly through caffeine tablets, cannabis, and methylphenidate. NE was associated with risky use of alcohol or tobacco, and to a lesser extent with ADHD symptoms and stress experience.Conclusions: Students are at risk of substance abuse and NE. Effective stress management and prevention approaches as well as low-threshold services are needed to identify and support students with risk profiles.

The Perceived Stress Scale 2&2: a two-factorial German short version of the Perceived Stress Scale

Background

Stress is among the leading causes for diseases. The assessment of subjectively perceived stress is essential for resilience research. While the Perceived Stress Scale (PSS) is a widely used questionnaire, a German short version of the scale is not yet available. In the current study, we developed such a short version using a machine learning approach for item reduction to facilitate the simultaneous optimization of multiple psychometric criteria.

Method

We recruited 1,437 participants from an online panel, who completed the German long version of the PSS along with measures of mental health and resilience. An ant-colony-optimization algorithm was used to select items, taking reliability, and construct validity into account. Findings on validity were visualized by psychological network models.

Results

We replicated a bifactor structure for the long version of the PSS and derived a two-factor German short version of the PSS with four items, the PSS-2&2. Its factors helplessness and self-efficacy showed differential associations with mental health indicators and resilience-related factors, with helplessness being mainly linked to mental distress.

Conclusion

The valid and economic short version of the PSS lends itself to be used in future resilience research. Our findings highlight the importance of the two-factor structure of the PSS short versions and challenge the validity of commonly used one-factor models. In cases where the general stress factor is of interest, researchers should use the longer versions of the PSS that allow for the interpretation of total scores, while the PSS-2&2 allows of an economic assessment of the PSS factors helplessness and self-efficacy.

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.

Public attitudes towards neurotechnology: Findings from two experiments concerning Brain Stimulation Devices (BSDs) and Brain-Computer Interfaces (BCIs)

This study contributes to the emerging literature on public perceptions of neurotechnological devices (NTDs) in their medical and non-medical applications, depending on their invasiveness, framing effects, and interindividual differences related to personal needs and values. We conducted two web-based between-subject experiments (2×2×2) using a representative, nation-wide sample of the adult population in Germany. Using vignettes describing how two NTDs, brain stimulation devices (BSDs; NExperiment 1 = 1,090) and brain-computer interfaces (BCIs; NExperiment 2 = 1,089), function, we randomly varied the purpose (treatment vs. enhancement) and invasiveness (noninvasive vs. invasive) of the NTD, and assessed framing effects (variable order of assessing moral acceptability first vs. willingness to use first). We found a moderate moral acceptance and willingness to use BSDs and BCIs. Respondents preferred treatment over enhancement purposes and noninvasive over invasive devices. We also found a framing effect and explored the role of personal characteristics as indicators of personal needs and values (e.g., stress, religiosity, and gender). Our results suggest that the future demand for BSDs or BCIs may depend on the purpose, invasiveness, and personal needs and values. These insights can inform technology developers about the public’s needs and concerns, and enrich legal and ethical debates.

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.

Effort–Reward Imbalance at Work and Prescription Drug Misuse—Prospective Evidence from Germany

This study examines how work stress affects the misuse of prescription drugs to augment mental performance without medical necessity (i.e., cognitive enhancement). Based on the effort–reward imbalance model, it can be assumed that a misalignment of effort exerted and rewards received increases prescription drug misuse, especially if employees overcommit. To test these assumptions, we conducted a prospective study using a nationwide web-based sample of the working population in Germany (N = 11,197). Effort, reward, and overcommitment were measured at t₁ and the 12 month frequency of prescription drug misuse for enhancing cognitive performance was measured at a one-year follow-up (t₂). The results show that 2.6% of the respondents engaged in such drug misuse, of which 22.7% reported frequent misuse. While we found no overall association between misuse frequency and effort, reward, or their imbalance, overcommitment was significantly associated with a higher misuse frequency. Moreover, at low levels of overcommitment, more effort and an effort–reward imbalance discouraged future prescription drug misuse, while higher overcommitment, more effort, and an imbalance increased it. These findings suggest that a stressful work environment is a risk factor for health-endangering behavior, and thereby underlines the importance of identifying groups at risk of misusing drugs.

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

Background

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

Methods

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

Results

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

Discussion

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

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

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

Prevalence and Correlates of Prescription Drug Misuse in a Nationwide Population Survey in Taiwan

BACKGROUND

Prescription drug misuse (PDM) is a critical mental health issue relating to psychiatric morbidity. This study investigated the prevalence of PDM and its associated psychopathology and psychosocial factors in the general population in Taiwan.

METHODS

The survey randomly selected a representative sample >15 year-olds using the stratified proportional randomization method. The measurements included demographic variables, previous experience with PDM, self-rated physical and mental health, health self-efficacy, risk factors for suicidality, and psychological distress.

RESULTS

The weighted one-year prevalence of PDM was 8.5% (n = 180) among 2126 participants. Those with psychological distress and lifetime suicide ideation (23.3%) or suicide attempts (5.0%) were significantly associated with PDM. PDM was also prevalent among those with poorer self-rated health and lower self-efficacy. Insomnia (OR = 1.52), depression (OR = 1.77), and low self-efficacy (OR = 2.29) had higher odds of PDM after adjustment in the logistic regression model.

CONCLUSIONS

Individuals who misused prescription drugs had a higher prevalence of psychological distress and suicidality and lower levels of self-rated health. Prescription drug misuse problems should be screened for early prevention when prescribing medications for people with insomnia, depression, or lower perceived health beliefs or conditions.

Pharmacological Neuroenhancement, Perceived Stress, and Resilience in Spine Surgeons-A Cross-Sectional Survey

BACKGROUND

Spine surgeons are usually exposed to high workload and demanding work conditions. Although the relationship between pharmacological neuroenhancement (PNE) and resilience (i.e., the ability to recover from stress), as well as perceived stress and resilience-enhancing factors, has been investigated in the general population, less is known about the impact of those factors in spine surgeons. This study aimed to close that gap by investigating the relationship between PNE use and resilience, perceived stress, or resilience-enhancing factors in spine surgeons.

METHODS

We conducted a cross-sectional survey in a sample of 582 spine surgeons in German-speaking countries (Austria, Germany, and Switzerland). Potentially predictive variables as well as the use of PNE were assessed by self-report questionnaires. We conducted stepwise logistic regression with backward elimination to assess the relationship among PNE use, perceived stress, resilience, and resilience-enhancing factors.

RESULTS

Lifetime prevalence for PNE use was 5.7%, with highest prevalence rates for antidepressants (2.6%). Each additional unit on the Perceived Stress Scale increased the risk for PNE use (odds ratio, 2.271; 95% confidence interval, 0.1.363-3.785; P = 0.002). No statistically significant results were found for the individual ability to recover from stress or resilience-enhancing factors.

CONCLUSIONS

Spine surgeons with higher levels of stress seem to be more prone to nonmedical use of PNE. Tailored interventions may improve the ability to cope with high perceived stress and prevent the use of PNE. Further research should examine the efficacy of those interventions on the prevention of PNE in spine surgeons.

Just "Like Coffee" or Neuroenhancement by Stimulants?

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

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

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

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

Resilience beyond reductionism: ethical and social dimensions of an emerging concept in the neurosciences

Since a number of years, popular and scientific interest in resilience is rapidly increasing. More recently, also neuroscientific research in resilience and the associated neurobiological findings is gaining more attention. Some of these neuroscientific findings might open up new measures to foster personal resilience, ranging from magnetic stimulation to pharmaceutical interventions and awareness-based techniques. Therefore, bioethics should also take a closer look at resilience and resilience research, which are today philosophically under-theorized. In this paper, we analyze different conceptualizations of resilience and argue that especially one-sided understandings of resilience which dismiss social and cultural contexts of personal resilience do pose social and ethical problems. On a social level such unbalanced views on resilience could hide and thereby stabilize structural social injustices, and on an individual level it might even lead to an aggravation of stress-related mental health problems by overexerting the individual. Furthermore, some forms of fostering resilience could be a latent form of human enhancement and trigger similar criticisms.

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

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

Psychiatric Comorbidity and Stress in Medical Students Using Neuroenhancers

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

The Prevalence of Beta-Blocker Use Among Medical Students at King Saud bin Abdulaziz University for Health Sciences in Jeddah, Saudi Arabia: A Cross-Sectional Study

Objectives

The aim of this study was to evaluate the prevalence and patterns of beta-blocker usage among medical students. Reasons for the use and demographic factors influencing their consumption were also evaluated.

Methods

This was an observational cross-sectional study among medical students at King Saud bin Abdulaziz University for Health Sciences (KSAU-HS) Jeddah, Saudi Arabia. Medical students were surveyed between February and April of 2019 using an electronic self-administered questionnaire. The questionnaire had close-ended questions, 18 of which were about demographics and 17 about propranolol use.

Results

A total of 234 medical students participated in the study, of whom 14.5% (95% CI: 10.44-19.49) reported using propranolol. Fifth-year medical students comprised 50% of propranolol users. The prevalence of males using propranolol was lower compared to females. The most common reasons for using propranolol were anxiety relief and performance enhancement before the objective structured clinical exams (OSCEs; 70.6%) and before oral presentations (38.2%).

Conclusion

The prevalence of propranolol use among medical students in KSAU-HS Jeddah was low compared to other studies, with the highest reported use among fifth-year medical students. The main reasons for using propranolol were anxiety relief during OSCEs and performance enhancement for presentations. Efforts must be directed towards raising medical students' awareness of the risks of inappropriate beta-blocker use to decrease its use and avoid potential adverse effects of the medication. 

[Questionnaire Survey Concerning Pharmacological Cognitive Enhancement among Undergraduates]

Pharmacological cognitive enhancement (PCE) usually refers to the use of medical substances by healthy individuals to improve mental performance. Given that certain substances have been frequently used for years, the long-term effectiveness and safety are essential to know but particularly difficult and costly to determine. Although PCE is a widespread and frequent phenomenon among university students in other countries, PCE prevalence in Japan has not been elucidated. The present study aimed to investigate the prevalence of and the attitude toward PCE among Japanese undergraduates over 3 years (2017-2019). Almost no student had ever used prescription drugs for cognitive enhancement. When asked, "Would you like to use drugs to enhance your cognitive performance?" 68.6-72.0% of the students answered, "No," 25.4-26.7% answered, "I couldn't say," and 2.5-4.8% answered, "Yes." These answers were associated with sex (2017-2018) and stress sensitivity (2019) but not with drinking, smoking, or stress of academic performance. Half of the students had used energy drinks for neural enhancement prior to an examination, which is similar to Western usage. The users of soft enhancers, such as energy drinks, are more likely to use other drugs. Given that caffeine can be a gateway for cognitive enhancement, future education addressing PCE among students should emphasize the side effects of prescription drugs as well as health risks of caffeine products.

Pharmakologisches Neuroenhancement in Deutschland

Hintergrund Die Angaben zur Verbreitung des pharmakologischen Neuroenhancements (pNE) in Deutschland variieren stark. Der Beitrag diskutiert, inwieweit dieser Umstand methodischen Aspekten der Prävalenzstudien geschuldet sein könnte.

Methode Der Beitrag gibt einen Überblick zum aktuellen Forschungsstand und beleuchtet methodische Probleme der Prävalenzforschung in Deutschland.

Ergebnisse Die Prävalenzangaben variieren je nach Erhebungsmethode, abgefragtem Zeitpunkt der Einnahme und untersuchten Zielgruppen und Stoffen bei verschreibungspflichtigen und illegalen Substanzen zwischen einem und 39%. Für frei erhältliche Mittel werden z. T. höhere Prävalenzen berichtet. Es lassen sich 4 große methodische Probleme der Forschung identifizieren: 1.) Die Heterogenität der Definitionen, 2.) die Heterogenität der Befragungsmethoden und die Qualität der Stichproben(ziehungen), 3.) Defizite bei der Frageformulierung, 4.) das Fehlen wichtiger Angaben in den zugehörigen Veröffentlichungen.

Schlussfolgerung Verlässliche Aussagen zur Verbreitung von pNE in Deutschland sind schwierig. Zwischen den Untersuchungen bestehen inhaltlich und methodisch große Unterschiede, die Ergebnisse lassen sich nur bedingt vergleichen. Notwendig sind regelmäßige bevölkerungsrepräsentative Erhebungen auf Basis einheitlicher Definitionen.

Placebo- and Nocebo-Effects in Cognitive Neuroenhancement: When Expectation Shapes Perception

Objective: The number of students using prescription drugs to improve cognitive performance has increased within the last years. There is first evidence that the expectation to receive a performance-enhancing drug alone can result in improved perceived and actual cognitive performance, suggesting a substantial placebo effect. In addition, expecting a placebo can result in lower perceived and actual cognitive performance, suggesting a nocebo effect. Yet, the underlying mechanisms of these effects remain to be elucidated. The aim of our study was to investigate whether the expectation of receiving a performance-increasing drug or a performance-impairing drug leads to changes in actual and perceived cognitive performance, compared to a control group without expectation manipulation. Methods: A total of N = 75 healthy adults were recruited for an experiment to "try cognitive performance-modulating drugs." A participant's actual cognitive performance (alertness, working memory, sustained attention, and divided attention) using the standardized test of attentional performance (TAP) as well as their performance expectation were assessed. Participants were randomly assigned in equal numbers to either receiving a placebo performance increasing nasal spray ("Modafinil") or a nocebo performance impairing nasal spray ("Vividrin^®") or no nasal spray (natural history). After placebo/nocebo nasal spray administration, cognitive performance was reassessed. Subsequent to the second assessment, participants rated their perceived change in cognitive performance, as well as adverse symptoms. Results: Unlike hypothesized, a positive or negative performance expectation did not result in changes in actual performance, corresponding to the induced expectation. Participants in the placebo-Modafinil group rated their perceived change in cognitive performance subsequent to the application of the nasal spray significantly better (d = 1.16) compared to the nocebo-Vividrin^® group. Additionally, participants who expected to receive Modafinil felt less tired than participants in the Vividrin^® group (d = 0.96). Conclusion: Manipulation of performance expectation affects the perceived change in performance and tiredness, but not the actual cognitive performance in healthy adults. This may explain why college students use such drugs despite their little impact on actual cognitive functioning.

Construct Validity and Population-Based Norms of the German Brief Resilience Scale (BRS)

Abstract. The Brief Resilience Scale (BRS) measures the ability to recover from stress. To provide further evidence for construct validity of the German BRS and to determine population-based norms, a large sample (N = 1,128) representative of the German adult population completed a survey including the BRS and instruments measuring perceived stress and the resilience factors optimism, self-efficacy, and locus of control. Confirmatory factor analyses showed best model fit for a five-factor model differentiating the ability to recover from stress from the three resilience factors. On the basis of latent and manifest correlations, convergent and discriminant validity of the BRS were fair to good. Female sex, older age, lower weekly working time, higher perceived stress, lower optimism, and self-efficacy as well as higher external locus of control predicted lower BRS scores, that is, lower ability to recover from stress.