Dr. Fernando Caudevilla is a medical doctor based in Madrid, specialist in Family and Community Medicine and university expert in Drug Addiction. Known in cyberspace as DoctorX, his work focuses on the development of risk reduction strategies for people who use drugs. He has published in high-impact scientific journals, advised national and international organizations and participated in international conferences focused on these areas. Currently he combines work in a health center with teaching and research activities related to drug use.