NEW YORK – The number of teenagers who experiment with recreational drugs is nearly the same as it was during its peak years in the early 1970s, reported James Anthony, Ph.D., at the annual conference of the Association for Research in Nervous and Mental Disease.
Dr. Anthony, who is chairman of the department of epidemiology at Michigan State University, East Lansing, said the trend in the past decade has been approximately 2.5 million new teenage cannabis users each year, an almost identical number as was seen in the early 1970s.
The number of people under the age of 18 years in the United States is also nearly identical to the figure from the early 1970s.
Abuse of prescription drugs such as stimulants, pain relievers, and sedatives appears to be even more common now than it was during the height of the post-1960s “drug culture” era, he noted at the conference, cosponsored by the New York Academy of Medicine.
So much for “Just say no.”
From a public health viewpoint, the important issue is not so much the absolute number of young people who try recreational drugs but the number of new users of those drugs who ultimately become dependent on them. This “conversion” rate from initial use to addiction is influenced by genetics, environmental factors, and most importantly, the nature of the drug itself. The statistics suggest that different substances have very different conversion rates.
According to data from the National Survey on Drug Use and Health (formerly the National Household Survey on Drug Abuse) and the National Comorbidity Survey databases, tobacco is by far the most addictive of the commonly abused substances. One in three individuals who tries tobacco will ultimately become dependent on it. Opiates are a close second, with one in four initial users becoming addicted. Crack and cocaine are next, inducing dependence in one in five and one in six first-time users, respectively. Alcohol causes dependence in one in seven to eight initial users, and stimulants cause dependence in one in nine. For cannabis, the figure is between 1 in 9 and 1 in 11.
Though many drug-avoidance programs that are aimed at teenagers identify cannabis as the “gateway” drug that leads young people to hard drug use, the statistics suggest that it is tobacco that really should carry that distinction, Dr. Anthony said. Dr. Anthony estimated that there are roughly 4.6 million actively drug-dependent individuals in the United States, and the vast majority go untreated for many years. Most people who do enter drug treatment programs have been drug dependent for an average of 10 years. In addition to alcohol and tobacco, cocaine is a major contributor to the problem.
“With cocaine, approximately 30% of the general population has the opportunity to try it, but only 50% of those who have the opportunity will try it. For cannabis, 85% of the population has the chance to try it, and 75% end up trying it,” he said.
Drug use and dependence patterns vary considerably from state to state. For example, estimates of the number of active adult cocaine users vary from 1.8% to 4%, with a U.S. average of 2.5%. The states with the highest prevalence are Nevada, Arizona, Ohio, North Carolina, Massachusetts, and Vermont.
Dr. Anthony said there are roughly 1.1 million new first-time cocaine users in the United States each year.
For cannabis, the number of users varies from 4.3% to 11% of the U.S. population, with an average of 6.2%. The highest-use states include Washington, Oregon, Nevada, Montana, Colorado, Utah, and New Hampshire. He estimated that there are roughly 14.6 million regular users of cannabis across the nation and 2.6 million first-time users each year.
The time frame for development of drug dependence seems to vary considerably for different drugs. With cocaine, between 5% and 6% of first-time users become dependent within the first 2 years of their initial experience.
This percentate rises to more than 16% within 6 years. “The pattern for tobacco looks a lot like cocaine,” Dr. Anthony said. With cannabis, between 3% and 4% of those who try the drug become dependent on it within the first 2 years, but the conversion factor drops off markedly after that. In this respect, alcohol is very similar to cannabis.
“If you're not addicted within the first 1 or 2 years, you probably will never be,” Dr. Anthony said.
Aside from the emergence of ecstasy (3,4-methylenedioxymethamphetamine) and related substances, the biggest change in patterns of drug abuse since the 1970s has to do with abuse of prescription drugs.