For Release April 1, 2006

New research supported by the National Institute on Drug Abuse (NIDA), National Institutes of Health, indicates that people who are trying to end their addiction to marijuana can benefit from a treatment program that combines motivational incentives with cognitive-behavioral therapy. The study is published in the April 2006 issue of the Journal of Consulting and Clinical Psychology.

"Demand for effective treatments for marijuana addiction increased significantly in the United States during the 1990s," says NIDA Director Dr. Nora D. Volkow. "Marijuana remains one of the most widely used drugs of abuse. Heavy use of the drug impairs a person's ability to form memories, recall events, and shift attention from one thing to another. Someone who smokes marijuana regularly may have many of the same respiratory problems that tobacco smokers do, such as daily cough and phlegm production, more frequent acute chest illnesses, and a heightened risk of lung infections. Thus, treatments to reduce and eliminate marijuana abuse will offer substantial public health benefits."

Dr. Alan Budney, of the University of Arkansas, and his colleagues at the University of Vermont followed 90 adult men and women diagnosed with marijuana dependence during the 14-week study. Participants were randomly assigned to one of three groups: (1) individuals who received vouchers as incentives to remain drug-free; (2) participants who received cognitive-behavioral therapy only (CBT); and (3) those who received both cognitive-behavioral therapy and vouchers (CBT+V). Vouchers were awarded for having marijuana-free urine samples. In cognitive-behavioral therapy people are taught to recognize unhelpful patterns of thinking and reacting, and modify or replace these with more realistic or helpful ones.

At the end of 3 months of treatment, 43 percent of the CBT+V group was no longer using marijuana, compared with 40 percent of the voucher group and 30 percent of the CBT group. But at the end of the 12-month follow-up, 37 percent of the CBT+V group was abstinent, compared with17 percent of the voucher group and 23 percent of the CBT group.

"We found that vouchers generated greater rates of marijuana abstinence during treatment compared with CBT alone, but that CBT enhanced the maintenance of the voucher effect during treatment," says Dr. Budney. "Together, the combination of vouchers and CBT resulted in higher abstinence rates during the year following treatment than vouchers alone. This suggests that CBT helps maintain the initial positive effect of using vouchers to initiate abstinence during treatment."

The maximum amount of earnings for patients receiving vouchers for abstinence was $570, (i.e., the amount earned if they were abstinent throughout the entire 14 weeks of treatment). Earnings could be redeemed for retail goods and services (movie passes, sports/hobby equipment, and work materials), but not for purchases that might encourage substance use. CBT alone consisted of 50-minute sessions each week, with fixed-value voucher payments to encourage participation. In CBT+V, participants reviewed their voucher earnings with their therapists at each visit and discussed how they might be used to support treatment goals of positive lifestyle changes and increased drug-free activities.

The scientists point out that the demographics of the study population - primarily white and male - may limit the ability to generalize their findings to other settings or populations.

"In addition," says Dr. Volkow, "although the study results are largely positive in that they show techniques that can lead marijuana-addicted patients to choose a more healthful lifestyle, there should be continued efforts to develop and evaluate effective treatments for marijuana addiction."

The National Institute on Drug Abuse is a component of the National Institutes of Health, U.S. Department of Health and Human Services. NIDA supports most of the world's research on the health aspects of drug abuse and addiction. The Institute carries out a large variety of programs to ensure the rapid dissemination of research information and its implementation in policy and practice. Fact sheets on the health effects of drugs of abuse and further information on NIDA research can be found on the NIDA web site at http://www.drugabuse.gov.