How Do ‘Brief Interventions’ Affect Cannabis Use in Teens?

Brief intervention is a general term used to describe short sessions of counseling or advice designed to educate people about various critical health issues. Substance abuse and addiction experts sometimes deliver information in this form in order to help reduce or eliminate an individual’s use of drugs or alcohol. In a study published in October 2013 in the journal Drug and Alcohol Dependence, researchers from four U.S. institutions examined the effectiveness of brief interventions in reducing the impact of cannabis use among U.S. teenagers. Some of the interventions under consideration were administered via computer, while others came directly from a therapist.


Brief Intervention Basics

There is no single definition for brief intervention, the federal Substance Abuse and Mental Health Services Administration (SAMHSA) reports. Doctors and other professionals (including addiction counselors, social workers or nurses) may use the term to refer to such things as the transmission of brief face-to-face advice on a given health topic; dissemination of a pamphlet or some other advice-containing, short-form written material; use of brief computer-based programs; use of single counseling or instructional sessions that don’t require ongoing involvement on the part of the therapist/doctor or client/patient; or use of a somewhat longer series of counseling or instructional sessions.

Professionals sometimes rely on brief interventions when they don’t have the time or means to reach an individual or group with longer, more fully developed forms of treatment. They also sometimes use brief interventions to reinforce the effects of longer, more traditional treatment. In either case, in the context of substance abuse or addiction, the general goal of employing such an intervention is typically to either support complete abstinence from the use of drugs or alcohol, or to support a less dangerous pattern of drug or alcohol use than the pattern a person currently maintains.

Cannabis Use in Teenagers

The term cannabis can refer to three distinct products from the Cannabis species of THC-containing plants: marijuana, a concentrated substance called hashish or a hashish derivative called hashish oil. In the U.S., marijuana far outstrips both hashish and hashish oil in terms of availability and popularity. According to figures compiled in 2012 by the National Institute on Drug Abuse and the University of Michigan, about 23 percent of all the nation’s high school seniors used marijuana in the month before the survey. Seventeen percent of all 10th-graders and approximately 6.5 percent of all eighth-graders also use the drug with the same amount of frequency. For close to a decade prior to 2007, marijuana use rates among U.S. teens actually fell. However, since 2007, short- and long-term usage rates have gone up for both 12th- and 10th-graders; short-term usage rates have also gone up for eighth-graders.

Effectiveness of Brief Interventions

In the study, researchers from the University of Michigan, the University of Arkansas, Wayne State University and the Department of Veterans Affairs assessed the effectiveness of brief interventions in 1,416 preteens and teenagers between the ages of 12 and 18. Of these, 328 had used some form of cannabis in the year prior to the start of the study. On a random basis, some of the participants received brief interventions in the form of computer-based programs, while others received brief interventions in the form of direct interaction with a therapist. Each participant then underwent follow-up examinations three months after treatment, half a year after treatment and one year after treatment.

After completing their three-month assessment of the effects of computer-based brief intervention, the researchers concluded that this form of treatment reduced the risks for some forms of drug use, as well as some of the worst potential outcomes of cannabis intake. However, it did not reduce the risks for using cannabis or alcohol, or for driving under the influence. Six months following treatment, computer-based brief intervention still reduced involvement in other forms of drug use, but not involvement in cannabis or alcohol use.

After completing their three-month assessment of the effects of therapist-directed brief interventions, the researchers found that this form of treatment helped reduce the risks for driving under the influence, but had no other effect on cannabis use or the use of alcohol or any other drug. Six months following treatment, therapist-directed brief interventions did not produce a positive effect on any aspect of cannabis or alcohol use, or on the use of any other drug. The researchers also concluded that neither computer-based brief intervention nor therapist-directed brief intervention produced a positive effect on any kind of substance use 12 months after treatment.

Significance and Considerations

Based on their findings, the study authors believe that both computer-based and therapist-directed brief interventions have usefulness as short-term treatments for reducing cannabis use and cannabis-related harms. However, they also note that other approaches must be used to extend the benefits gained from brief interventions for longer periods of time.