Marijuana Treatment Project
MTP was funded by the Center for Substance Abuse Treatment in 1997 and conducted in three States (Connecticut, Florida, and Washington) over a 3-year period. MTP compared two active treatments with a delayed treatment control condition (Stephens et al. 2002). One active treatment consisted of nine individual counseling sessions delivered over a 12-week period. The initial sessions focused on MET. These were followed by CBT skills training along with additional case management if needed. With some minor modifications, the BMDC described in this manual was based on the nine-session treatment evaluated in MTP. The other active treatment used in MTP consisted of two MET sessions delivered over a 1-month period.
A total of 450 participants from diverse ethnic and socioeconomic backgrounds was recruited through media advertisements and agency referrals. These individuals were primarily male (68%) and on average 36 years old. Sixty-nine percent of the group was white, with 12 percent African-American, 17 percent Hispanic, and 1 percent other, which included Asian-American, Native American, or unknown (1% is accounted for by rounding error). Approximately 60 percent of the sample was unmarried. Individuals in this group had, on average, 14 years of education. Sixty-nine percent worked full time, 14 percent worked part time, 12 percent were unemployed, and 4 percent were students, retired people, or homemakers (1% is accounted for by rounding error). Those who worked had been employed at their current jobs for approximately 5 years (Stephens et al. 2002).
Ninety-two percent of the study participants felt that they were currently dependent on marijuana. At the time of the screening, almost the entire sample (99.8%) felt that marijuana was the biggest problem for them (relative to other drugs or alcohol). The group reported smoking marijuana on 82 of the past 90 days (91% of the days), smoked an average of 3.7 times a day, and reported that the number of days since their last smoking episode was 1.2. Use of other drugs and alcohol in the past 30 days was infrequent, in part because individuals who were concurrently dependent on alcohol or drugs other than marijuana were ineligible.
The results of MTP showed a consistent pattern of differences between groups. The delayed treatment group changed little from baseline to the 4-month followup on almost all outcome measures. At each followup point over a 12-month period, both active treatments produced outcomes superior to the 4-month delayed treatment control condition. The nine-session intervention produced significantly greater reductions in marijuana use and associated consequences than the two-session intervention. Abstinence rates at the 4- and 9-month
followups for the nine-session intervention were 23 percent and 13 percent, respectively. The differences between the two active treatments appeared as early as 4 weeks into the treatment period and were sustained throughout the first 9 months of followup.
As was the case in the findings of the studies discussed above, MTP findings demonstrated a moderate degree of efficacy of counseling interventions with adults who are marijuana dependent.
Outcomes from the two-session MET intervention were less positive than those found in the study by Stephens and colleagues (2000), suggesting that the effectiveness of brief and more intensive treatment may vary with the population studied, the content of the therapy, and the skills of the clinicians.
The MTP results indicate that even a brief two-session treatment is associated with substantial reductions in marijuana use and related problems. Nevertheless, a significant percentage of these chronic smokers continue or return to marijuana use, albeit at reduced levels. For example, although the nine-session intervention resulted in a 60-percent reduction in marijuana use up to a year after the end of therapy, it did not produce sufficient abstinence rates to eliminate completely the risk of accidents, injuries, chronic disease, and a return to marijuana dependence.
Nevertheless, even with reduced levels of use, both treatments were associated with significant reductions in anxiety levels, legal problems, and employment problems. It is important to note that, although a substantial percentage of clients did not succeed in becoming abstinent, many individuals remained motivated to overcome their dependence. At the 9- month post treatment assessment, 82 percent had relapsed and 68 percent indicated that they had tried to stop using marijuana at some point between their 4- and 9-month assessment interviews.
These findings suggest that participants who receive a single episode of care remain motivated to change and thus should be followed by aggressive community outreach and support services.
Outreach, Access, and Support Groups
The demonstration of several efficacious treatment interventions for marijuana dependence raises additional questions about how best to engage in treatment people who chronically use marijuana and how best to maintain improvements following treatment. Unfortunately, little research has been conducted in these areas.
Marijuana Anonymous (MA) groups, a mutual-help fellowship based on the principles and traditions of Alcoholics Anonymous (AA), exist in a number of States and internationally. In addition to traditional meetings, MA sessions are held on line. (The organization's Web site address is www.marijuana-anonymous.org. Its toll-free telephone number is 800-766-7669.) No research has been conducted yet to evaluate the effectiveness of MA, either alone or in combination with formal treatment. Nevertheless, research on AA suggests that mutual-help organizations can play an important role in recovery, both alone and in combination with formal treatment programs (McCrady and Miller 1993).
Individuals who use marijuana chronically as their primary drug tend not to seek treatment in traditional drug treatment settings, but it appears from MTP and other studies that when given the opportunity, they respond to treatment. Given the promising initial research on treatment for cannabis dependence and the potential benefits of brief motivational and cognitive behavioral relapse prevention therapies, there is now sufficient evidence to support the development of focused treatment programs for this population. The manual-guided therapies developed for these projects, particularly MTP, should be transferable to specialized outpatient clinics and to behavioral health care practitioners.