Frequently Asked Questions about Adolescent Drug Use, Part 2

3. How do adolescents become addicted to drugs, and which factors increase risk? 

Addiction occurs when repeated use of drugs changes how a person’s brain functions over time. The transition from voluntary to compulsive drug use reflects changes in the brain’s natural inhibition and reward centers that keep a person from exerting control over the impulse to use drugs even when there are negative consequences—the defining characteristic of addiction.

Some people are more vulnerable to this process than others, due to a range of possible risk factors. Stressful early life experiences such as being abused or suffering other forms of trauma are one important risk factor. Adolescents with a history of physical and/or sexual abuse are more likely to be diagnosed with substance use disorders.

Many other risk factors, including genetic vulnerability, prenatal exposure to alcohol or other drugs, lack of parental supervision or monitoring, and association with drug-using peers also play an important role.

At the same time, a wide range of genetic and environmental influences that promote strong psychosocial development and resilience may work to balance or counteract risk factors, making it ultimately hard to predict which individuals will develop substance use disorders and which won’t.

4. Is it possible for teens to become addicted to marijuana? 

Yes. Contrary to common belief, marijuana is addictive. Estimates from research suggest that about 9 percent of users become addicted to marijuana; this number increases among those who start young (to about 17 percent, or 1 in 6) and among daily users (to 25–50 percent).

Thus, many of the nearly 7 percent of high school seniors who (according to annual survey data) report smoking marijuana daily or almost daily are well on their way to addiction, if not already addicted, and may be functioning at a sub-optimal level in their schoolwork and in other areas of their lives.
Long-term marijuana users who try to quit report withdrawal symptoms including irritability, sleeplessness, decreased appetite, anxiety, and drug craving, all of which can make it difficult to stay off the drug. Behavioral interventions, including Cognitive-Behavioral Therapy and Contingency Management (providing tangible incentives to patients who remain drug-free) have proven to be effective in treating marijuana addiction.

Although no medications are currently available to treat marijuana addiction, it is possible that medications to ease marijuana withdrawal, block its intoxicating effects, and prevent relapse may emerge from recent discoveries about the workings of the endocannabinoid system, a signaling system in the body and brain that uses chemicals related to the active ingredients in marijuana.

Legalization of marijuana for adult recreational use and for medicinal purposes is currently the subject of much public debate. Whatever the outcome, public health experts are worried about use increasing among adolescents, since marijuana use as a teen may harm the developing brain, lower IQ, and seriously impair the ability to drive safely, especially when combined with alcohol.

Parents seeking more information about the effects of marijuana on teens are encouraged to see information offered on NIDA’s Web site: http://www.drugabuse.gov/drugs-abuse/ marijuana.