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Motivational Enhancement Therapy and Cognitive Behavioral Therapy for Adolescent Cannabis Users: 5 Sessions

Introduction and Background

Introduction and Organization

This manual is designed to help train substance abuse treatment counselors to conduct a brief five-session treatment intervention for adolescents with cannabis use disorders presenting for outpatient treatment. It combines two sessions of motivational enhancement therapy provided individually and three sessions of cognitive behavioral therapy provided in a group format. The program is referred to as MET/CBT5. Although this will be one of the first applications of these approaches to adolescent treatment, related brief intervention approaches with adults have proved very effective (Bien, Miller & Tonigan, 1993; Miller et al., 1995; Miller & Rollnick, 1991; Siegal, Rapp, Fisher, Cole & Wagner, 1993; Stark & Kane, 1985; Stephens, Roffman & Simpson, 1994; Zweben, Pearlman & Li, 1988). In the CYT study, the approach was also an efficient intervention because its personalized feedback report was based on the intake assessments already done as part of the research protocol.

The treatment described in this manual was designed to address the problem of marijuana use by adolescents. Section I reviews the scope, effects, and patterns of the marijuana problem. Section II provides a brief overview of the Cannabis Youth Treatment project for which this manual was developed. Section III covers the scientific basis for this intervention. Section IV provides step-by-step procedures for actually implementing this treatment protocol.

Scope and Significance of the Marijuana Problem

Although marijuana use has dropped slightly in the past few years, it is still the most widely used and most readily available illicit psychoactive substance in the United States (Office of Applied Studies, 2000). In 1998, the rate of marijuana use during the month preceding the survey was more than twice that of all other drugs combined (8.3 percent vs. 4.0 percent) and higher than the rate of getting drunk (7.7 percent). Moreover, the rates of marijuana use for 8th graders are twice as high as the rates in 1992. The rate of daily use of marijuana is higher than the rate of daily use of alcohol, and that rate has not gone down (Monitoring the Future, 1999). Furthermore, similar trends in marijuana use are reported in regional surveys of junior and senior high school students (Godley et al., 1996; Hartwell et al., 1996; Markwood, McDermiet & Godley, 2000). Marijuana use has historically been inversely related to an adolescent’s perceived risk of using it (Johnson, Hoffman & Gerstein, 1996), and currently this perception among 12th graders is at the lowest point since 1982 (Monitoring the Future, 1999). Unfortunately, these perceptions do not match the facts.

Relative to nonusers, adolescents who used marijuana (and typically alcohol) weekly were 3 to 47 times more likely to have a host of problems including symptoms of dependence, emergency room admissions, dropping out of school, behavioral problems, fighting, non-drug-related legal problems, other legal problems, and being arrested. Unfortunately, fewer than 1 in 10 adolescents with past-year symptoms of dependence received treatment (Dennis & McGeary, 1999; Dennis, Godley & Titus, 1999). From 1992 to 1997, the number of adolescents presenting to publicly funded treatment for marijuana problems increased more than 200 percent; in 1997, 81 percent of adolescents admitted had a primary, secondary, or tertiary problem with marijuana (Dennis, Dawud-Noursi & Muck, in press; Office of Applied Studies, 1999). Marijuana is also the leading substance mentioned in adolescent emergency room admissions and autopsy reports and is believed to be one of the major contributing factors to violent deaths and accidents among adolescents; it has been reported to be involved in as many as 30 percent of adolescent motor vehicle crashes, 20 percent of ado-lescent homicides, 13 percent of adolescent suicides, and 10 percent of other unintentional injuries among adolescents (Centers for Disease Control and Prevention, 1997; McKeown, Jackson & Valois, 1997; Office of Applied Studies, 1995).

An additional danger associated with marijuana use and observed in adolescents is a sequential pattern of involvement in legal and illegal drugs (Kandel, 1982). Marijuana is frequently a stepping stone that bridges the gap between cigarette and alcohol use and use of other drugs (e.g., cocaine, heroin) (Kandel & Faust, 1975). This stagelike progression of substance abuse, known as the gateway phenomenon, is common among youth from all socioeconomic and racial backgrounds (Kandel & Yamaguchi, 1993). This pattern has also been observed in French and Israeli cohorts (Adler & Kandel, 1981) and has been confirmed in a longitudinal cohort followed from ages 15 to 35 (Kandel et al., 1992). In sum, adolescent marijuana use is intimately linked to future drug involvement. Less serious experimental use portends a decline in later use of all drugs, whereas more serious use often snowballs into involvement with increasingly addictive and potent drugs.

Effects of Marijuana Use

The physical effects of marijuana use include fluctuations in blood pressure, decreased salivation, mild unsteadiness, impaired coordination, hunger, drowsiness, slowed speech, and respiratory difficulties (Cohen, 1979; Hall, 1995; National Institute on Drug Abuse, August 1986), a decrease in the immune response, suppression of testosterone production in males (Cohen, 1979), and a decrease in respiratory vital capacity.

The effect of marijuana use during adolescence on central nervous system development remains unclear. Adolescents abstaining after chronic marijuana use have shown evidence of persistent short-term memory impairment on neuropsychological tests (Millsaps et al., 1994). Pope and Yurgelun-Todd (1996) have recently demonstrated an indirect association between the frequency of marijuana use among college students and cogni-tive impairment on tests involving card sorting and word learning. These effects are likely to have a significant impact on academic functioning. Whether neuropsychological deficits preceded the onset of drug use or were the result of long-term exposure to marijuana is unclear. Clinical studies suggest that longer term and/or heavier use of marijuana is directly associated with losses of abstract and logical thinking, the ability to focus attention and filter out irrelevant information, and the ability to resolve normal emotional conflicts, mental confusion, and memory problems (Lundvqist, 1995; Solowij, 1995; Solowij et al., 1995). These studies also suggest that it may take 6 to 12 weeks for even partial recovery of cognitive functioning to occur and that this process is prolonged when there is any interim use.

A commonly noted effect of chronic marijuana use is amotivational syndrome, characterized by apathy, decreased attention span, poor judgment, diminished capacity to carry out long-term plans, social with-drawal, and a preoccupation with acquiring marijuana (Cohen, 1980, 1981; Schwartz, 1987). Amotivational syndrome is attributed to heavy cannabis use and has been observed in adolescents (Schwartz, 1987). However, Musty and Kaback (1995) reported that amotivational symptoms in heavy marijuana users between the ages of 19 and 21 might actually be due to co-occurring depression. Whether amotivational syndrome is a primary or a secondary diagnosis in subpopulations of marijuana abusers has not yet been resolved.

Marijuana use has also been associated with a wide variety of social-psychological problems. Rob and colleagues (1990) compared adolescent marijuana users and nonusers on a number of psychosocial factors. Marijuana use was associated with poorer family relationships, poorer school performance, and higher levels of school absenteeism. Other illicit drugs were used almost exclusively by marijuana users, rather than those who did not use marijuana, and marijuana users were more than three times as likely as nonusers to be sexually active, to drink alcohol three or more times per week, and to smoke cigarettes. Serious marijuana use is associated with a multitude of behavioral, developmental, and family problems (Kleinman et al., 1988), including conduct disorder, crime and delinquency, school failure, unwanted pregnancy, and escalating drug involvement (Donovan & Jessor, 1985; Farrell et al., 1992; Hawkins et al., 1992; Jessor & Jessor, 1977).

Patterns of Substance Use

Anecdotal and longitudinal studies have suggested that the age of onset for regular marijuana use most frequently occurs during early adolescence (before age 15) and is almost always completely intertwined with alcohol use (Hops, 1998; Patterson, 1998). Public domain data from 5,143 adolescents surveyed for the Office of Applied Studies (1996) and 1995 National Household Survey on Drug Abuse (NHSDA) show that after age 15, daily use stabilizes at a rate of about 2 to 3 percent, weekly use at about 3 to 4 percent, and monthly use at about 6 to 7 percent. Parallel data for alcohol use are consistent with the literature and suggest an early pattern of onset. Weekly use increases from less than 1 percent at age 12, to 3 percent at age 14, to 10 percent at age 18. Daily use increases from 4 percent at age 12, to 7 percent at age 14, to 9 percent at age 18. Thus, for both marijuana and alcohol, adolescence is clearly a significant period both for initial use and for increasingly more frequent rates of use.

With regard to comorbidity, over two-thirds of the monthly and weekly marijuana users are drinking alcohol—with a third drinking it daily or weekly. Among the daily marijuana users, 27 percent were drinking weekly and 35 percent were drinking daily. Thus, marijuana and alcohol use is starting at similar times, and patterns of their use are largely intertwined.

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