In an effort to enhance outcomes for adolescent substance abuse (primarily focusing on marijuana), we sought to create a developmentally-appropriate outpatient CM-based intervention 27, 28
. This model integrates four empirically-based interventions. First
, an abstinence-based reinforcement intervention (voucher program) is utilized to enhance motivation to engage in treatment and engender marijuana and other drug abstinence. Monetary-based, incentives are provided by the clinic for abstinence documented by urine and breath testing. This procedure is highly similar to the oft-replicated, abstinence reinforcement programs effective in adult treatment studies 29, 30
, a parent-directed CM program is employed to further motivate initiation and maintenance of drug abstinence and to better manage other related behavior problems. Parents are likely to consider their adolescent’s marijuana use as problematic, and are usually motivated to take action. However, they may not have the skills to effectively change their adolescent’s behavior. With careful training and resources, parents (or guardians) are a natural choice for delivering a CM program that could also enhance or engender motivation to abstain. Our parent CM program includes two components. Parents implement a substance monitoring contract (SMC) that specifies positive and negative consequences to be delivered by the parents in response to documented abstinence or use. The Family Management Curriculum (FMC) from the Adolescent Transitions Program (ATP) teaches parents basic principles and skills to decrease problem behaviors and increase prosocial behaviors, and has demonstrated efficacy for treating conduct disorder 31
. Because conduct problems often predate and co-occur with adolescent substance abuse 32, 33
, we reasoned that targeting conduct problems, in addition to drug abstinence, might further enhance outcomes in treatment for adolescent substance abuse. Parent compliance with family management treatment positively impacts treatment outcome (Nye et al., 1995), hence the third
component of this model uses CM to motivate parent participation. Here, parents earn chances to win prizes via an innovative positive reinforcement program 34
for actively participating in each treatment component.
, adolescents receive individual therapy (MET/CBT) to enhance motivation and provide coping skills training focused on achieving and maintaining abstinence 35, 36
. Weekly 90-minute sessions are held for 14 weeks, with approximately 45 minutes for the individual teen session, and 45 minutes for the parent training session. At the end of the 14 weeks, all families are offered an additional 12 weeks of once weekly substance testing to facilitate parental monitoring and are referred, when appropriate, to other community resources. In summary, the combination of the individual therapy, voucher program, family management curriculum, and incentives for parent participation is designed to increase (a) adolescents’ motivation to achieve and maintain abstinence, (b) parents’ abilities to use effective parenting to decrease substance use and other behavior problems, and (c) adolescents’ coping skills to help them achieve and adapt to a substance-free lifestyle.
Adolescent CM Implementation Details
In order to facilitate evaluation, generalization, and dissemination of CM approaches to adolescent substance abuse, it is important to provide procedural details about the key implementation variables that influence the efficacy of any CM intervention: schedule, magnitude, type of consequence, target behavior, and monitoring. Our abstinence-based incentive program was designed so that 1) substance use and its absence are readily detected; 2) abstinence is reinforced; 3) substance use results in a loss of reinforcement; and 4) positive reinforcement gleaned from drug abstinence is used to increase non-drug reinforcement. We use the following schedule for our clinic-based CM intervention for marijuana and other substance abstinence. We offer teens the opportunity to earn rewards twice weekly for 14 weeks based on documented substance abstinence. This schedule allows for frequent opportunities for earning reinforcement, while making it highly probable that any marijuana used at any time during a given week would be detected (see below for a detailed discussion of monitoring issues). Regarding magnitude, during Weeks 1-2, participants receive $5 vouchers for each specimen provided independent of test results because of the issues summarized below with the prolonged presence of marijuana metabolites in urine. These vouchers reinforce the provision of the urine specimen (attendance and compliance with the program) and serve as priming reinforcers to demonstrate what can be gained via the voucher program. Subsequent to this, during Weeks 3-14 adolescents earn vouchers only if they provide a substance-negative specimen and parents report abstinence (see discussion of target below). The voucher value starts at $1.50, escalates by $1.50 with each consecutive negative specimen, and a $10 bonus is earned for each two consecutive negative results. Vouchers are reset back to their initial value if results were positive, from which they escalate again after three consecutive negative results. This schedule and magnitude of reinforcement is specifically designed to encourage achievement of longer periods of continuous abstinence 30
. The total magnitude earnings for an adolescent who provides 4 valid urine specimens during the first two weeks of treatment and is abstinent throughout Weeks 3-14 is $590. Voucher programs with this same schedule and magnitude have been used successfully with adult marijuana users 29, 37
Monetary-based vouchers are the type of incentive used. Adolescents earned vouchers (coupons reflecting the amount earned that day and the total voucher balance available on that day), each time abstinence is documented as described below. Vouchers earned are redeemed for goods or services therapists deemed in concert with the treatment goal of increasing prosocial, non-drug related activities. Examples of voucher purchases include gift cards or certificates to clothing stores, large chain stores, restaurants, and movie theaters; no cash is provided to adolescents.
The target of this CM program is abstinence from marijuana, alcohol and other drugs. Note that in adults, targeting multiple drugs simultaneously is generally a more difficult goal to achieve than targeting the primary abused substance only 38
. Nonetheless, with adolescents we target all substances for the following reasons. First, although marijuana is the primary drug of abuse for most teens enrolled in treatment, they quite frequently use alcohol, occasionally use other drugs such as opiates cocaine, or amphetamines, and of recent commonly report prescription drug misuse. In addition to the obvious potential for harm of these other substances, we felt that parents would not be receptive to a treatment that provides reinforcement for marijuana abstinence in situations where we, or they, detect their teen using other substances typically considered even more harmful than marijuana. Our experience to date using this procedure suggests that placing voucher contingencies on all drugs of abuse with adolescents who primarily abuse marijuana is not problematic. Little other drug use is usually observed, attrition is low, and the majority of adolescents earn incentives for drug abstinence during the intervention.
To monitor the target behavior (substance abstinence) we use the following procedures. Because the primary target substance is marijuana, and in order to develop an appropriate monitoring schedule to detect marijuana abstinence, we considered the following information in developing our schedule and monitoring procedure. Urinalysis testing provides the usual and typically best method for obtaining the documented evidence needed to effectively administer a CM program targeting drug abstinence. With marijuana, such testing poses some unique issues. First, regular, heavy marijuana users are likely to test positive for marijuana use for 1-3 weeks after cessation at detection levels of 50ng/ml of 11-nor-9-carboxy-9-tetrahydrocannabinol (THCCOOH), the primary marijuana metabolite, which is an accepted cutoff level for documenting recent abstinence. Thus, in our voucher program, we provide a two-week notice prior to initiating the voucher program that informs clients that it will take two weeks of abstinence from marijuana for them to achieve a negative urinalysis result. Thus, reinforcement for abstinence must be delayed which is the reason for reinforcing participation only during Weeks 1-2. Note that some clinical agencies and researchers have begun to use quantitative or semi-quantitative testing for THCCOOH levels as a means to differentiate abstinence from residual THCCOOH in the urine. These methods could potentially reduce the need for delaying reinforcement. However, the accuracy of these procedures for differentiating recent abstinence from reduced use or past use depends heavily on very frequent testing in the early weeks of abstinence (daily or almost daily testing is required to reliably interpret the findings), which would be much costlier than the qualitative tests that rely on standardized cutoffs, and pose additional burden for participants.
A second related concern much less frequently encountered is the possibility that a participant can provide a urine specimen that is negative for cannabis use on one day and then positive for cannabis the next day during the early weeks of abstinence. This can occur because marijuana metabolites are stored in the fatty cells and the rate of their release can vary depending on activities like exercise. We have observed this only a handful of times, but it is worth noting.
A third concern is that urinary THCCOOH levels are affected by the dilution factor of the specific urine specimen provided. Many clients either intentionally or inadvertently drink large quantities of liquid that dilute a urine specimen such that a false negative test result might be obtained. If possible, a method to screen for dilute specimens should be used as part of the urine toxicology program. Measurement of creatinine is one method to approximate the dilution factor. Invalid specimens (creatinine below 30 mg/dl) results in a request to provide a replacement specimen within 4-24 hours. Failure to submit a scheduled specimen or replacement specimen is treated as a positive result, unless the parent provides an appropriate reason for not being able to attend the clinic. Notwithstanding these issues, the methods to detect recent marijuana use described here have been used effectively and without substantial problems in multiple clinical trials. A comprehensive understanding of the urine toxicology process, however, is necessary to facilitate implementation of an effective program.
In order to accurately monitor substance abstinence, we conduct urine tests on a twice per week schedule. This schedule has been used with marijuana using adults, but differs from the original voucher program for cocaine. Our decision to modify the schedule was twofold. First, we felt it was more practical for participants to make two rather than three visits to the clinic per week. Second, we were concerned that a single instance of cannabis use would carryover to multiple urine tests with the more frequent schedule. The twice a week schedule is sufficient to detect most any cannabis use without exacerbating the potential for carryover positive tests. In summary, we believed that the practical advantages and reduction in the carryover problem gained with the twice per week schedule outweighed the potential benefits that might come from using a voucher delivery schedule that would reinforce abstinence more frequently.
An alcohol breath test is performed at each visit, and parents are provided with and trained to use disposable breathalyzers to test for alcohol use at home. All parents are given five disposable breathalyzers that detect breath alcohol levels at .02/bal and above each week to use at home to detect alcohol use. Parents in the CM condition were instructed to ask their youth to take the breath test when parents suspected alcohol use, using the following procedure. Parents asked the teen if he or she used alcohol that day. If the answer was yes, parents did not administer a breath test, and followed steps outlined below for a positive test. If the teen said no, they did not use alcohol, the parent asked him or her to take the breath test. If the breath test was positive or the test was refused, parents implemented the agreed upon consequence (procedure described below) and reported the positive test to the clinic.
Urine specimens are obtained under same-gender, staff observation to minimize risk of provision of invalid or tampered specimens. Specimens are immediately tested onsite for marijuana, cocaine, opioids, benzodiazepines, amphetamines, and methamphetamines using the Enzyme-Multiplied Immunoassay Technique (EMIT). Rapid or quick tests that can be easily obtained and used without extensive training are good alternatives to use of EMIT or other types of analyzers. Note that if either the adolescent or parents report substance use, or a positive urine specimen or breath test is obtained, the adolescent is considered positive for the purpose of CM implementation.
CM Interventions Implemented by Parents
In addition to the CM procedures implemented by clinic staff, we provide explicit instruction to parents in how to use CM procedures at home. First, with guidance from the therapist, parents develop a substance monitoring contract (SMC) that focuses on substance use or abstinence. The contract specifies positive and negative consequences to be delivered by the parents in response to documented abstinence or use (based on results of the aforementioned substance monitoring procedures) (see ). The consequences are determined via a collaborative process between therapist, parent and adolescent, and revaluated each week during weekly counseling sessions. This contract uses the same target (abstinence), schedule (twice per week), and monitoring method (urine drug testing, breath alcohol testing and self/parent reports) as our clinic based CM. Parents individualize the type of consequence (monetary, voucher type system, privileges) and the magnitude of the consequences, and these factors change throughout treatment in response to treatment success or failure.
Parents also receive a comprehensive behavioral parent training program delivered during weekly sessions. The Family Management Curriculum of the Adolescent Transitions program, is used to teach parents basic principles and skills designed to decrease problem behaviors and increase prosocial behaviors 39
. This program, designed to target youth conduct problems seemed likely to yield broad benefits because conduct problems are highly co-morbid with and strong predictors of poor outcomes among treated adolescent substance abusers 40, 41
. This curriculum is highly consistent with the CM model, as parents are taught to select and define problem (target) behaviors and track (monitor) those behaviors over time. Parents clearly specify in advance the type of consequences they will use to increase positive behaviors, similar to those used in the substance monitoring contract, the schedule on which consequences will be provided (e.g., daily), and the magnitude of the consequence. Similar procedures are followed to identify consequences for negative behaviors.
We also utilize the Fishbowl method 34
to enhance parent participation and compliance. Each week, parents are asked to complete six tasks: attend therapy, attend mid-week urine testing appointments, implement the SMC (twice per week), complete homework, and administer breathalyzers. Parents earn one draw from the Fishbowl for each task. Each draw results in obtaining a winning (75% chance) or non-winning slip (25% chance). Winning slips range in value from small ($1-$2: 68% chance), to medium ($20: 7% chance), to large prizes ($100: 1% chance). Prizes are delivered immediately and included gift certificates to restaurants, ice cream shops, movie theaters, and grocery stores.
Initial Adolescent CM Trial Results
We completed an initial two-group randomized trial comparing cognitive behavioral therapy (CBT)+CM (abstinence-based reinforcement and parent-based CM) to CBT+parent drug education (PDE; an attention control condition) 28
. Of the 69 youth enrolled (14-18 years of age), 31 met DSM-IV criteria for marijuana abuse, 30 for marijuana dependence, and 8 adolescents did not meet criteria for abuse or dependence, but reported regular marijuana use. As hypothesized, CM enhanced continuous abstinence outcomes, engendering more weeks of continuous marijuana abstinence during treatment (7.6 wks vs. CBT+PDE 5.1 wks; p=.04, d=.48, medium effect). Those in the CM group were also more likely to achieve ≥8 weeks of continuous abstinence (53% vs. 30%, p=.06) and ≥10 weeks of continuous abstinence (50% vs. 19%, p=.006).
Despite during treatment differences in abstinence, we did not observe a significant between-group difference in abstinence post treatment. There was an increase in marijuana use from discharge to the 9 month follow up, that, while not returning to intake levels, is of significant concern. Across psychopathology and parenting measures, the CM condition tended to show better outcomes, with significant main effects of treatment condition on negative discipline and externalizing. However, the treatment x time effects were not significant on any scale, indicating that adolescents in both conditions improved on measures of internalizing and externalizing psychopathology, and parents in both conditions showed parenting improvements. There was some evidence of better parental monitoring in the CM condition. Although both groups were given free breathalyzers by their clinicians and instructed in their use, CM mothers administered significantly more breathalyzers during treatment than CBT+PDE mothers (mean=12.9 for CBT+CM vs. 2.97 for CBT+PDE, t(67)=3.66, p<.001). We hypothesize that CBT+CM mothers administered more breathalyzers because they were instructed in contingency contracting, providing them with a clear plan to use the testing results.
The lack of significant treatment condition differences during post-treatment were unexpected and may have resulted from low power to detect differences, a more potent effect of the comparison treatment than expected (rates of abstinence appear good in both conditions compared to prior treatment studies), or simply a less potent intervention effect than expected. Particularly relevant to this discussion of contingency management, the comparison intervention included incentives for participation in counseling and twice weekly urine testing; systematically provided test results to parents; and provided weekly counseling and case management to parents. Although this condition was meant to serve as an “attention control” for the CM intervention, we expect that it was active and enhanced outcomes that would have been achieved with MET/CBT alone and might be considered an alternative model warranting future study. In particular, parents in the comparison condition may have responded to the urine drug testing results in a similar manner to parents in the CM condition (i.e., withdrawal of privileges or other punishment delivered contingently following positive drug tests, rewards delivered contingently following negative drug tests). The likely tendency for at least some parents to respond in this way may have served to make outcomes more similar across conditions. Moreover, the CM incentive program for attendance and participation may have positively impacted retention thereby facilitating the impact of the individual counseling and the parent program.