A study published in 2011 by scientists of the University Hospital Mainz already examined the use of stimulants for cognitive performance enhancement by adult students at school and university. One finding was that the survey participants more often resort to illegal stimulants such as amphetamines or cocaine than to prescription psychotropic drugs to improve their performance (the research question carefully excluded hedonistic motives for use). For example, only 0.2 % of the students reported having taken drugs containing methylphenidate or modafinil for the purpose of cognitive enhancement during the year preceding the survey, while almost one percent had used illegal stimulants.

With a similarly designed survey, but using the randomized response method to ensure maximum anonymity, in 2013 another team of Mainz researchers found that 20% of the students surveyed had taken prescription or illegal stimulants for the purpose of cognitive performance enhancement in the previous year. At present, it is not possible to say how great the influence of the survey method is on this dramatically higher estimate of the prevalence of cognitive enhancement among German students. Apart from a reduction in the number of unreported cases, the difference to older surveys could also be explained by the increased openness to neuroenhancement. Furthermore, the much higher proportion of students who admit to cognitive enhancement is probably partly due to the fact that the new study now also considers caffeine tablets to be enhancement preparations.

In 2014 and 2018/2019, the health insurance provider Deutsche Angestellten-Krankenkasse DAK repeated a survey of its members on the subject of "Doping in the Workplace", first conducted in 2008, using almost identical methodology. The survey focused on pharmacological neuroenhancement, specifically asking only about prescription drugs and taking into account the purpose of cognitive performance enhancement as well as the interest in mood improvement. While in 2008 4.7 % of the surveyed employees stated that they had already tried pharmacological neuroenhancement in this sense at least once in their lives, the proportion had risen to 6.7 % in 2014 and slightly decreased to 5.5 % in 2018/2019. The proportion of regular dopers in the workplace is estimated to have been constant from 2008 till 2018/2019 at roughly 2 %.

A study published in 2012 on "Forms of stress compensation and performance enhancement among students" refers to the data collected in an online survey of almost 8,000 students. The invitation to the survey was sent to the 33,000 or so participants of the representative HISBUS panel. As the authors of the study include stress compensation among the purposes of brain doping alongside performance enhancement, it is not inappropriate that they include cannabis users among the brain dopers, even though cannabis is certainly not the drug of choice for cognitive performance enhancement. However, the inclusion of cannabis significantly increases the proportion of students identified by the study as brain dopers, as almost a quarter of the 5 % of brain dopers had used cannabis products, while methylphenidate, the most common pharmacological agent, had been taken by only 18 %. The HISBUS survey also classifies 5 % of students as "soft-enhancers" who have used herbal or homeopathic substances, vitamin preparations or caffeine to improve their performance at least once during their studies. Nevertheless, the study reveals that 88 % of the students have never taken any special substances in order to cope with the demands of their studies.