Mixed Report Card on Teen Substance Use

Marijuana use in teens increases while alcohol and tobacco use decline

/ Author:  / Reviewed by: Robert Carlson, M.D

Teens may be drinking and smoking less – but they are smoking out more. Cigarette smoking and alcohol use are at their lowest levels among teens while pot use has climbed.

A survey of almost 50,000 students across the US has found that use of alcohol and smoking cigarettes has continued declining and are at all-time lows.

The problem is marijuana. Also at all-time lows are students' perception of the drug's harm. Even though use of other illegal drugs had decreased, use of marijuana is increasing.

In fact, among high school seniors, the perception that occasionally using marijuana is harmful is at its lowest level since 1983, and belief that regular use is harmful is at its lowest since 1979.

"Teach your kids the harms of marijuana."

The study is based on the results of the Monitoring the Future survey, an annual survey of adolescents in eighth, tenth and twelfth grades that has been conducted over the past 38 years with funding from the National Institutes of Health.

The survey came from 45,449 students from 395 public and private schools in the US. It measured drug, alcohol and cigarette use in the students and their attitudes toward these substances.

The students answer questions about how much they use cigarettes or marijuana on a daily basis, as well as how much they've used them in the past month, the past year and in their lifetimes.

The researchers found that alcohol and cigarette use have continued to decline and are at the lowest levels since the survey began.

Alcohol and Tobacco Use Continue Declining

While 33 percent of eighth graders reported having drunk any alcohol in their lifetimes last year, this year's number dropped to just over 29 percent. The highest number ever reported among this age group was 55.8 percent in 1994.

Among tenth graders, 54 percent reported having used alcohol at least one in their lifetime, significantly lower than the 72 percent who reported as much in 1997.

Rates of binge drinking, defined at five or more drinks in a row within the past two weeks, also decreased among eighth graders. Only 5.1 percent of eighth graders reported binge drinking, compared to 6.4 percent last year and the peak of 13.3 percent in 1996.

Smoking rates among eighth graders have decreased from 18.4 percent last year to 15.5 percent this year in terms of any lifetime use of cigarettes. The peak in 1996 was 50 percent.

There is also less lifetime use of cigarettes among tenth graders, from 30.4 percent last year to 27.7 percent this year.

Meanwhile, almost 20 percent of high school seniors reported having smoked small cigars in the past year, and 18 percent reported using hookah water pipes.

Pot Smoking Increases

However, use of marijuana has increased. A total of 6.5 percent of high school seniors reported smoking marijuana every day, compared to 5.1 percent in 2007.

Over a third (36 percent) of seniors said they'd smoked marijuana in the past year, and almost 23 percent had smoked it within the past month.

Although only 1.1 percent of eighth graders said they smoke pot daily, 3.5 percent of tenth graders reported as much. The rates of use in the past month were 17 percent among tenth graders and 6.5 percent among eighth graders.

The students also don't see marijuana as harmful as much as they used to – perception of the drug's harm are at their lowest rates since the survey starting asking questions about it.

Dr. Joshua Evans, pediatrician at DMC Children's Hospital of Michigan (part of the Detroit Medical Center) and assistant professor of pediatrics, Wayne State University School of Medicine and dailyRx Contributing Expert, said "One of the big concerns with marijuana is that it is a classic gateway drug with potential to lead kids to trying other drugs. In addition to the known effect on IQ, depending on the source, marijuana may be laced with other harmful or toxic substances that have a more immediate effect."

Among eighth graders, 41.7 percent believe using marijuana occasionally is harmful, and 66.9 percent believe regular use is harmful.

Among seniors, 20.6 percent see occasional use as harmful, and 44.1 percent think regular use is harmful – the lowest rate since 1979.

This perception is out of step with reality since studies have shown that regular use of marijuana is linked to a decrease in children's IQ and problems with cognitive development. In fact, earlier this year, a study in the Proceedings of the National Academy of Sciences found that teenage users of marijuana who continue smoking as adults have about an average 8 fewer IQ points by the time they're 38.

"THC, a key ingredient in marijuana, alters the ability of the hippocampus, a brain area related to learning and memory, to communicate effectively with other brain regions," said Nora D. Volkow, MD, the director of the National Institute of Drug Abuse, in a release about the study. "In addition, we know from recent research that marijuana use that begins during adolescence can lower IQ and impair other measures of mental function into adulthood."

Illegal Drug Use Declines While Non-Medical Prescription Drug Use Fluctuates

When it comes to prescription drug abuse, students' use is declining with some drugs but increasing with others. The survey showed that students usually get these drugs from family and friends.

The 5.6 percent of high school seniors who reported having abused cough and cold medicines that contain dextromethorphan over the past year has remained steady for several years.

However, the 7.5 percent who reported using Vicodin, an opioid painkiller, are part of the gradual decrease in use of this drug, which began declining in 2010, when use had been about 10 percent since 2002.

Yet seniors are using the stimulant Adderall more often, with 7.6 percent reporting using it this year, up from the 2009 number of 5.4 percent. More seniors also perceive this drug to be less harmful. Just a third (35 percent) of seniors said they believe occasional Adderall use is risky.

Rates of other illegal drugs besides marijuana have continued declining. Use of ecstasy among twelfth graders dropped from 5.3 percent last year to 3.8 percent this year.

Eighth graders reported the lowest level ever of illegal drug use (besides marijuana) at 5.5 percent. The 10.8 percent of tenth graders and 17 percent of twelfth graders who reported ever using illegal drugs are also all-time lows.

In the first year that the survey asked about use of "bath salts," only 1.3 percent of high school seniors reported having ever used these stimulants.

There was decline in use of the hallucinogenic plant Salvia divinorum among seniors, from 5.9 percent last year to 4.4 percent this year.

While the researchers reported optimism for the continuing declines in use of most illegal drugs, alcohol and tobacco, the increases in marijuana and the decreasing perception of its harm raised red flags.

"We are very encouraged by the marked declines in tobacco use among youth," said Howard K. Koh, MD, MPH, assistant secretary for health for the US Department of Health and Human Services, in a release about the findings. "However, the documented use of non-cigarette tobacco products continues to be a concern. Preventing addiction includes helping kids be tobacco free so they can enjoy a fighting chance for health."

The findings were released by the National Institute of Health on December 19. The research was funded by the National Institute of Drug Abuse.

Reviewed by: 
Review Date: 
December 18, 2012