Epidemiology Marijuana

Marijuana remains the most commonly used drug in the United States. The growth in the use of marijuana in the 1960s, 1970s was followed by a steady decline in the early 1990s. Nevertheless, there was a surge in the use of marijuana among high school students in 1993.

The data collected by the National Institute for the Study of Drug Abuse in 1991 show that almost 68 million Americans (33% of the population) have tried marijuana at least once in their lifetime. The percentage of those who have ever tried marijuana is as follows: 13% of adolescents (from 12 to 17 years old), 51% of young people (from 18 to 25 years old) and 33% of adults (from 26 years old and above).
These and other data are shown in chart 10-1. The most noticeable changes occur with adolescents. Between 1979 and 1991, the distribution of marijuana among adolescents dropped from 68% to 51%, the number of users once a year fell from 47% to 25% and constantly consuming (once a month) from 35% to 13%. The number of people who have ever used among adults has been steadily increasing, probably as a result of the growing up of people who used marijuana in the previous period.

Several findings from the studies of the 1990s are worth mentioning. First, men are more likely to use marijuana than women. The only exceptions were teenagers from 12 to 17 years old, where men and women use marijuana about equally. The second thing that matters is the frequency of use. The percentage of people using marijuana 100 times or more (among those who have used it at least once in their life) is: 14% for 12-17-year-olds, 21% for 18-25-year-olds, 27% for 26-34-year-olds and 20% for 34-year-olds and older. As a result, data comparing the percentage of regular smokers of marijuana and those who use drugs periodically, reflect the fact that non-regular smokers of marijuana use other drugs more often than regular ones. As an example: 28% of young marijuana smokers account for a certain number of people who use other drugs. In particular, 11% use cocaine.

Chart 10-2 shows that marijuana use in the United States increased significantly in 1993. For example, the number of older students who use marijuana every day increased from 1.9% to 2.4%. This shows that attitudes and stereotypes about drugs among older schoolchildren are “softened,” schoolchildren are no longer confident in the negative consequences of drug use and in their personal failures, which drug use entails.