RESUMEN
Two long-term surveys of drug use have been carried out in Ontario, Canada - one involving middle-and high-school students, and the other adults in the general population. These studies revealed that use of tobacco and alcohol is common and that Cannabis is the most widely used illicit drug by both the students and adults (15.9 percent and 9.5 percent, respectively, in 1987). Use of other illicit drugs is much less common. The trend data from 1977 to 1987 show a decrease in all drug use among students and a basically stable pattern among adults, with the exception of an upward trend in cocaine use. A study of adult cocaine users in the community found that half had experienced intense cravings for cocaine and other adverse effects. Demographic information was also gathered that made it possible to outline the most common characteristics of Cannabis and cocaine users