Marijuana Abuse and Dependence
Conditions
Keywords
Marijuana, Treatment, Behavioral, Computer, Internet
Brief summary
More US residents are dependent on marijuana than on any other illicit drug, and the number enrolled in treatment for marijuana continues to increase such that it is now comparable to that for cocaine and heroin. This application seeks to advance the overarching goal to develop and disseminate cost-effective treatments for marijuana dependence that can address this growing problem. The researchers' previous research suggests that an intervention comprising motivational enhancement, cognitive-behavioral, and contingency-management components (MET/CBT/CM) produces greater rates of successful and durable outcomes than has been demonstrated previously. However, three issues relevant to its efficacy and eventual dissemination must be confronted. First, the outcomes achieved can only be characterized as modest; many individuals do not respond to the treatment and relapse rates remain problematic. Second, access is limited by the availability of trained providers. Third, the cost of delivering the treatment is higher than more traditional outpatient interventions. To address these issues, Specific Aim 1 is to develop and test a computer-assisted version of MET/CBT/CM. Computerized treatments have the potential to increase overall effectiveness of treatment services by increasing availability of and access to potent treatments, and by applying innovative technology to enhance outcomes. During Year 1, the intervention will be developed and pilot tested. An interactive program that showed promise in a previous trial for opioid dependence will be modified and enhanced to deliver individualized MET/CBT/CM using effective computer learning technologies. These technologies and access to the MET/CBT/CM program made available via the Internet between treatment sessions and after treatment ends have the potential to promote better learning and more use of coping skills, which in turn can improve outcomes. During Years 2-4 a randomized trial will provide an initial efficacy test of cMET/CBT/CM by comparing it with a brief treatment (MET) and with therapist-delivered MET/CBT/CM. Specific Aim 2 is to learn more about how behavioral treatments like MET/CBT/CM work by focusing on two putative mechanisms of action examined in prior trials: self-efficacy/coping skills and impulsivity/delay discounting. The experimental design will provide a unique opportunity to explore such mechanisms in a novel context- where the therapist is vs. is not a prominent part of the treatment. The proposed project will address the objectives of NIDA's Behavioral and Integrative Treatment Development Program by providing research on technology-assisted treatment that attempts to make treatment delivery less complex, easier to access, and less costly - while retaining or improving its effectiveness. Findings will inform future studies designed to refine the technology and how it is applied; conduct more definitive effectiveness testing; test generality to other populations including adolescents; and to further advance translation to community settings.
Interventions
BEHAVIORALPsychotherapy
Nine session treatment
BEHAVIORALComputerized Psychotherapy
Nine session computer delivered treatment
BEHAVIORALMotivational enhancement therapy
Two session treatment
Sponsors
Dartmouth-Hitchcock Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* 18 years of age or older * Meet criteria for current DSM-IV diagnosis of marijuana abuse or dependence * Report use of marijuana on at least 40 of the past 90 days * Severe psychological distress
Exclusion criteria
* Current dependence on alcohol or any other drug (except nicotine) * Participation in treatment for alcohol/drug problem * A legal status which will interfere with participation * Plans to move out of the area in the next 12 months * Living with someone who is already enrolled in the project * Not living within approximately 30 miles of the research site * Not being fluent in English
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Consecutive Weeks of Marijuana Abstinence | From the start of treatment through the end of the active treatment period, i.e., 12 weeks. | Longest period of marijuana abstinence achieved during the 12-week treatment period documented by urine testing and self-report. |
| Point Prevalence Abstinence Post Treatment | 9 months (from the end of treatment to 9 months post-treatment). | Percent of participants that were marijuana abstinent based on urine toxicology testing at each follow up assessment across 9 month follow up period ( at the end of treatment, at 3-months, 6-months, and 9 months post the end of treatment). |
Countries
United States
Participant flow
Recruitment details
Recruitment opened in November 2008 and closed in May 2011. Recruitment practices included newspaper and radio advertisements, flyers, and posters distributed in local businesses and agencies. The study took place at an outpatient psychiatry clinic.
Pre-assignment details
Participants were excluded from trial prior to group assignment for at least one of the following:no evidence of marijuana use in at least 40 of the past 90 days prior to enrollment,participant met criteria for dependence on alcohol or illicit drugs,evidence of illicit drug use or K-2 use,interfering medical/psychiatric illness,or active refusal.
Participants by arm
| Arm | Count |
|---|---|
| 1-MET/CBT/CM Therapist delivered motivational enhancement therapy plus cognitive behavioral therapy plus contingency management (tMET/CBT/CM)
Nine weekly therapy sessions delivered in weeks 1-8 and week 12
2 times per week urine drug testing
Contingency management program delivered monetary-based incentives contingent on each marijuana-negative urine toxicology test. | 29 |
| 2-cMET/CBT/CM Computer-delievered (c) MET/CBT/CM treatment
Computer delivered nine MET/CBT sessions during weeks 1-8 and week 12. therapist delivered 3 brief supportive counseling sessions during weeks 1, 4, and 12.
2 times per week urine drug testing.
Contingency management program delivered monetary-based incentives contingent on each marijuana-negative urine toxicology test. | 30 |
| 3-tMET Therapist delivered motivational enhancement therapy (tMET)
Two session treatment with sessions delivered during weeks 1 and 4.
Two times per week urine drug testing.
Non-contingent incentives delivered for attending each urine testing appointment. | 16 |
| Total | 75 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 |
|---|---|---|---|---|
| Overall Study | Lost to Follow-up | 13 | 9 | 7 |
Baseline characteristics
| Characteristic | 1-MET/CBT/CM | 2-cMET/CBT/CM | 3-tMET | Total |
|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 29 Participants | 30 Participants | 16 Participants | 75 Participants |
| Age, Continuous | 34.7 years STANDARD_DEVIATION 11.06 | 34.87 years STANDARD_DEVIATION 11.07 | 35 years STANDARD_DEVIATION 8.95 | 34.85 years STANDARD_DEVIATION 10.52 |
| Point prevalence abstinence | 0 percentage of participants | 13 percentage of participants | 12.5 percentage of participants | 25.5 percentage of participants |
| Region of Enrollment United States | 29 participants | 30 participants | 16 participants | 75 participants |
| Sex: Female, Male Female | 12 Participants | 14 Participants | 7 Participants | 33 Participants |
| Sex: Female, Male Male | 17 Participants | 16 Participants | 9 Participants | 42 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 29 | 0 / 30 | 0 / 16 |
| serious Total, serious adverse events | 0 / 29 | 0 / 30 | 0 / 16 |
Outcome results
Primary
Consecutive Weeks of Marijuana Abstinence
Longest period of marijuana abstinence achieved during the 12-week treatment period documented by urine testing and self-report.
Time frame: From the start of treatment through the end of the active treatment period, i.e., 12 weeks.
Population: Intent to Treat
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| 1-tMET/CBT/CM | Consecutive Weeks of Marijuana Abstinence | 3.55 consecutive weeks of abstinence | Standard Deviation 4.39 |
| 2-cMET/CBT/CM | Consecutive Weeks of Marijuana Abstinence | 2.82 consecutive weeks of abstinence | Standard Deviation 4.21 |
| 3-tMET | Consecutive Weeks of Marijuana Abstinence | 0.78 consecutive weeks of abstinence | Standard Deviation 1.97 |
Comparison: Pairwise comparison; non-parametric tests performed because of non-normal distributionp-value: <0.05accelerated bootstrapping
Comparison: pairwise comparison; non-parametric analysisp-value: <0.05accelerated bootstrapping
Comparison: nonparametric pairwise comparison; non-normal distributionp-value: >0.05accelerated bootstrapping
Primary
Point Prevalence Abstinence Post Treatment
Percent of participants that were marijuana abstinent based on urine toxicology testing at each follow up assessment across 9 month follow up period ( at the end of treatment, at 3-months, 6-months, and 9 months post the end of treatment).
Time frame: 9 months (from the end of treatment to 9 months post-treatment).
Population: Intent to Treat
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| 1-tMET/CBT/CM | Point Prevalence Abstinence Post Treatment | End of Treatment (ETX) Abstinence Rate | 44.8 pecentage of participants abstinent |
| 1-tMET/CBT/CM | Point Prevalence Abstinence Post Treatment | 3-Months Post Treatment Abstinence Rate | 20.7 pecentage of participants abstinent |
| 1-tMET/CBT/CM | Point Prevalence Abstinence Post Treatment | 6-months Post Treatment Abstinence Rate | 17.2 pecentage of participants abstinent |
| 1-tMET/CBT/CM | Point Prevalence Abstinence Post Treatment | 9-months Post Treatment Abstinence Rate | 10.3 pecentage of participants abstinent |
| 2-cMET/CBT/CM | Point Prevalence Abstinence Post Treatment | 9-months Post Treatment Abstinence Rate | 23.3 pecentage of participants abstinent |
| 2-cMET/CBT/CM | Point Prevalence Abstinence Post Treatment | End of Treatment (ETX) Abstinence Rate | 46.7 pecentage of participants abstinent |
| 2-cMET/CBT/CM | Point Prevalence Abstinence Post Treatment | 6-months Post Treatment Abstinence Rate | 36.7 pecentage of participants abstinent |
| 2-cMET/CBT/CM | Point Prevalence Abstinence Post Treatment | 3-Months Post Treatment Abstinence Rate | 36.7 pecentage of participants abstinent |
| 3-tMET | Point Prevalence Abstinence Post Treatment | 9-months Post Treatment Abstinence Rate | 6.3 pecentage of participants abstinent |
| 3-tMET | Point Prevalence Abstinence Post Treatment | 3-Months Post Treatment Abstinence Rate | 6.3 pecentage of participants abstinent |
| 3-tMET | Point Prevalence Abstinence Post Treatment | 6-months Post Treatment Abstinence Rate | 6.3 pecentage of participants abstinent |
| 3-tMET | Point Prevalence Abstinence Post Treatment | End of Treatment (ETX) Abstinence Rate | 12.5 pecentage of participants abstinent |
Comparison: pairwise comparisons among groups across 4 follow-up timepointsp-value: <0.05piecewise mixed model with logit link an