Substance Use and Abuse

How prevalent is substance use and abuse? A large nationwide survey of U.S. high school students indicated that two thirds of ninth graders had tried alcohol, half had tried tobacco, and one third had tried marijuana. Many of these students reported trying these substances before 13 years of age (11% tried marijuana, 19% tried cigarettes, and 34% tried alcohol) (Eaton et al., 2006). Smaller percentages of ninth graders had tried cocaine and other drugs. Use of inhalants (sniffing glue, paint, or aerosols) is a more recent phenomenon: More ninth graders than twelfth graders reported ever having tried inhalants. Use of Ecstasy (also known as MDMA), is becoming more common, with 6% of teens nationwide reporting having used it at least once.

Statistics shows ethnic differences in substance use from the same nationwide survey. Use of all the drugs listed except marijuana was lower among African Americans than among non-Hispanic whites or Hispanics. Hispanics reported the highest use of marijuana, cocaine, Ecstasy, methamphetamines, and heroin; white students show the highest rates of tobacco use. Other large-scale surveys show that the rate of using many illegal drugs has declined in recent years, by about 10% among twelfth graders. However, the use of inhalants, sedatives, and the addictive prescription drug OxyContin has increased (Cleveland & Wiebe, 2003; Dishion & Owen, 2002; Johnston, O'Malley, Bachman, & Schulenberg, 2006).

The rates of alcohol and tobacco (and increasingly, marijuana) use are concerning. As you saw above, a majority of teens have at least tried alcohol by the time they reach high school and many drink regularly. Most obtain alcohol from their own homes. Binge drinking, defined as consuming five or more drinks on a single occasion, is also becoming more common among high school students, with 20% of ninth graders and 37% of twelfth graders saying they have binged at least once (Eaton et al., 2006). Alcohol use by teens is related to many problem behaviors and outcomes, including traffic accidents and fatalities, early sexual activity, rape, poor school performance, and poorer mental health. It can be difficult to tease apart which factors lead to and which result from alcohol use, but alcohol use by teens is clearly linked to many problems. Tobacco use has declined significantly since the mid-1990s, but this trend is weakening for both cigarettes and smokeless tobacco (currently used by about 7% of teens). Teens hold much more negative attitudes toward smoking and its health risks than in past years, there is less cigarette advertising that targets them, and they see much more antismoking advertising. The sky-rocketing cost of cigarettes is probably also a factor in declining rates of tobacco use (Johnston et al., 2006). Finally, marijuana is by far the most frequently used drug that is illegal for both adolescents and adults. It equals tobacco in the percentage of teens who are regular users.

Adolescents are far more likely to experiment with alcohol and drugs than younger or older individuals. But many who experiment or only use occasionally do not experience long-term effects—as long as they escape short-term negative outcomes such as accidents and sexual risk-taking. As you might expect, early onset of use (e.g., using alcohol before age 14 or illegal drugs before age 15) is associated with increasing use over time and greater risk for alcohol and drug disorders (Chassin et al., 2004). But what risk factors can adults watch for before substance use begins?

Characteristics of the individual are related to substance use. Those who develop substance problems are more likely to be sensation seeking, aggressive, impulsive, and have poor behavioral control—and many of these qualities are evident between 3 and 5 years of age. Problems with cognitive skills related to self-regulation such as planning, organizing, and selective attention are also related to increased risk of substance abuse. A history of antisocial behavior, including aggressiveness and conduct problems, is also a risk factor (Chassin et a1., 2004).

Teens' beliefs, values, and experiences also play a role in whether they use alcohol and drugs. Those who believe that alcohol and drugs are a threat to their health or their future goals are less likely to use them, while those that think of drug use as less risky and more fun are at increased risk. Teens who describe themselves as more religious are less likely to try alcohol or drugs. And those who experience high levels of stress are at an increased risk. Having experienced physical or sexual abuse in childhood or witnessed family or neighborhood violence increases the risk. For these teens, substance use may be an attempt to cope with circumstances that are overwhelming to them (McIntosh, MacDonald, & McKeganey, 2005; Merrill, Salazar, & Gardner, 2001; Wallace, Brown, & Bachman, 2003).

Family factors are important in predicting substance problems. Those with a family history of substance abuse are at higher risk, probably for several reasons. Families may share a genetic susceptibility for drug use and dependence, and parents who abuse alcohol or drugs provide a model of substance use for their children. Prenatal exposure to alcohol or drugs may increase the sensitivity of receptors for the substances in the child's brain or may contribute to conduct and self-control problems in the child. Alcohol and drugs are also likely to be more available in homes with a family history of substance use.

Parenting practices are also important. Harsh, inconsistent, or permissive discipline is associated with higher levels of substance use. Not surprisingly, poor parental monitoring increases the risk as well because these parents have less knowledge of what their teens are doing and who they're with. More authoritative parenting (high in warmth and responsiveness, but with appropriate expectations and discipline) is associated with lower levels of substance use. A close relationship with parents reduces the likelihood of drug use, probably because these parents monitor their adolescents more closely and perhaps have more influence on their teens' friendships. Parents also communicate their beliefs and values about substance use by their own behavior and through discussions with their children; they can also reinforce positive connections with peers, school, clubs, churches, and other organizations that affect the risk of substance use.

Of all the factors that have been studied, having friends who use alcohol and other drugs is the strongest predictor of teen substance use. Friends who use provide a model of substance use, opportunity to engage in substance use, access to the substances, and reinforcement for using. Of course, it is difficult to know exactly how to interpret this relationship. Do teens who are more likely to use substances select friends who are also likely to do so? Or are teens who would otherwise be unlikely to use drugs being influenced to use by their friends? As you might expect, it can be difficult for research to sort out these possibilities, but it seems that both selection and socialization influences are important. Regardless, it's a good idea for parents to monitor who their teens are spending time with and get to know their teen's friends.

As you can see, adolescents with more difficult temperaments, cognitive difficulties, and poor self-control of behavior and emotions are at higher risk for substance problems. These individual vulnerabilities may interact with more coercive or lax parenting practices, leading to problems with schooling and lack of acceptance into a positive peer group. These children and teens may then become increasingly involved with deviant peer groups that model, reinforce, and provide opportunities to engage in substance use—much the same way that these elements work together to produce conduct problems, aggression, and delinquent behavior.