Abstract
This issue focuses on the prevention of dysfunctional use of substances as well as on illness related to alcohol, tobacco, and other drug use. In societies where tobacco and alcohol use derive from longstanding tradition, prevention in its broadest sense emerges as a serious consideration. As a general concept, prevention is undertaken at three levels: (1) primary prevention, which includes all efforts to prevent pathologic conditions in those who are well; (2) secondary prevention, which aims to decrease the length and severity of illness through detection and early intervention; and (3) tertiary prevention, which seeks to decrease long-term effects and illness and prevent or delay recurrences.