The main subject of the following thesis is the pharmacotherapy of Attention-deficit hyperactivity disorder. Prior to delving into the main subject, an introduction to the key aspects of this disorder is discussed, such as symptoms, diagnostic criteria, prevalence estimates, comorbidities and differential diagnosis, etiology, and the importance of proper management of ADHD as well as the consequences and costs of unmanaged ADHD. A quick overview of non-pharmacotherapeutic strategies is mentioned, as well as a brief discussion on the research and development of new drugs for the treatment of ADHD and lastly, the differences in ADHD in females and the use of medication during pregnancy.