Randomized Response Estimates for the 12-Month Prevalence of Cognitive-Enhancing Drug Use in University Students


  • Supported by a grant from the World Anti-Doping Agency (09M5) and the Initiative PRO Humanities and Social Sciences 2015 of the Johannes Gutenberg University, Mainz, Germany.

For questions or comments, contact Perikles Simon, M.D., Ph.D., Department of Sports Medicine, Rehabilitation and Disease Prevention, Faculty of Social Science, Media and Sports, Johannes Gutenberg University, Albert-Schweitzer-Str. 22, D-55128 Mainz, Germany; e-mail: simonpe@uni-mainz.de.


Study Objective

To estimate the 12-month prevalence of cognitive-enhancing drug use.


Paper-and-pencil questionnaire that used the randomized response technique.


University in Mainz, Germany.


A total of 2569 university students who completed the questionnaire.

Measurements and Main Results

An anonymous, specialized questionnaire that used the randomized response technique was distributed to students at the beginning of classes and was collected afterward. From the responses, we calculated the prevalence of students taking drugs only to improve their cognitive performance and not to treat underlying mental disorders such as attention-deficit–hyperactivity disorder, depression, and sleep disorders. The estimated 12-month prevalence of using cognitive-enhancing drugs was 20%. Prevalence varied by sex (male 23.7%, female 17.0%), field of study (highest in students studying sports-related fields, 25.4%), and semester (first semester 24.3%, beyond first semester 16.7%). To our knowledge, this is the first time that the randomized response technique has been used to survey students about cognitive-enhancing drug use.


Using the randomized response technique, our questionnaire provided data that showed a high 12-month prevalence of cognitive-enhancing drug use in German university students. Our study suggests that other direct survey techniques have underestimated the use of these drugs. Drug prevention programs need to be established at universities to address this issue.