Following the First World War and the social destruction it wrought, the problem of national degeneration became a major concern for Ottoman-Turkish physicians, especially psychiatrists who were major proponents of policies to improve the health of the population as a basis of economic and political strength. During the 1920s and 1930s, alcohol and drug addiction was a major target of their efforts to improve public health in Istanbul, where they viewed an increase in taverns and drunkenness as an assault on the city’s neighborhoods. I explore how the urban environment served as both a pressure cooker for addiction and setting for public outreach by psychiatrists to remedy this social problem. Their concern with addiction as a major threat to the nation’s mental health reflects a concept of Turkishness perceived as a shared biological essence that symbolized national potential. This essence, or sum of racial qualities, was also represented in an individual’s mental capacity to be conscious of them. The desire to work towards the perfection of one’s race was not only a matter of consciousness, but a moral duty of conscience as well. Following this logic, suffering from addiction could prevent someone from ever becoming a proper national subject, just as lacking a sense of Turkishness or national duty could potentially indicate that someone was mentally ill. At a time when nation-building was conceived as dependent on the vitality of the Turkish race, many physicians saw preventing degeneration as the main solution to the nation’s problems. As one of the major signs of degeneration, addiction was rendered all the more visible by city life in Istanbul where psychiatrists formed organizations like the Green Crescent Society and Society for Mental Hygiene to warn the public about the harm intoxicants posed to the future of the nation. Drawing on the publications of such organizations, I trace how new ideas about mental pathology were racialized and intertwined with the project of nation-building as well as how the urban public may have encountered them.