Abstract: The misuse of prescription stimulants, such as Ritalin®, has received increasing attention both in the public and the academic sphere. These stimulants are normally prescribed to people with ADHD, but students sometimes use them to increase their study performances. Despite alarming prevalence rates and concerns with respect to safety, research on stimulant misuse is still in its infancy. This PhD thesis will address two main research objectives: (1) demand side: Understand the prevalence, determinants and process of misusing stimulants among Flemish students, and (2) supply side: Understand the sources students use to acquire these stimulants as well as the off-label prescribing behavior of general practitioners. A mixed-method research design is used. First, the results show that 8.5% of students have ever used prescription stimulants to enhance their performance without it being part of a treatment (e.g., ADHD). Second, multiple personal (e.g., self-perceived ADHD, academic stress), social (e.g., living situation, social norm) and cultural (e.g., competitive study-environment, financial worries) factors were identified as risk factors of students’ intention to misuse stimulants. Third, analyses indicated four subtypes of misusers: (1) the normalization subtype indicates having concentration problems and structurally uses stimulants to deal with these problems; (2) the rescue subtype is able to study without stimulants, but occasionally uses them to cope with high academic demands and/or personal stressors; (3) the experimental subtype does not have an academic need to use stimulants, but temporarily uses them out of curiosity; and (4) the performance subtype also not really needs the medication, but perceives it as a convenient tool to structurally facilitate academic life. Finally, the results showed GPs’ perspectives on whether or not to off-label prescribe stimulants to students for academic purposes. Results identified two groups of GPs: (1) hard-liners who strictly follow medical guidelines and ...