The purpose of this 3-year trial is to test the efficacy of transdermal nicotine patch versus placebo patch on marijuana withdrawal symptoms in cannabis-dependent individuals, using a randomized, double-blind, and placebo-controlled design. This proposal is in response to RFA-DA-10-016(R01) Medications Development for Cannabis-Related Disorders. Consistent with the goals of this RFA, the overall goal of the proposed project is to assess the impact of transdermal nicotine patch (TNP) on marijuana (MJ) withdrawal (negative affect and craving motivated by negative affect) symptoms in MJ-dependent individuals.

The aim of this proposal is to accurately assess the effects of TNP on MJ withdrawal symptoms across 15 days of biochemically confirmed MJ abstinence using a placebo-controlled, double-blind, randomly assigned treatment design, while closely monitoring any potential adverse effects, including changes in nicotine use and dependence.

To achieve these goals, 116 carefully screened cannabis-dependent individuals (58 female) will be randomly assigned to one of two doses (0 mg or 7mg nicotine) of TNP (transdermal nicotine patch) while they abstain from MJ for 15 days. Subjects will be administered a follow-up phone interview 30 days after the termination of treatment to assess the effects of nicotine-patch treatment on: 1) frequency of nicotine and tobacco smoking intake, 2) Fagerstrom Test of Nicotine Dependence (FTND)-assessed nicotine dependence, 3) new use of nicotine during the time since completion of the study, and 4) marijuana and other drug use patterns. Large financial contingencies will be used to provide a high degree of abstinence and study completion. This will be the first adequately powered study to assess the effects of TNP on MJ negative affect-related withdrawal symptoms and urges to use MJ. Withdrawal patterns and abstinence will be assessed in two groups of MJ-dependent individuals: 1) those who rarely or never smoke tobacco, and 2) those who smoke four or fewer tobacco cigarettes per day (very-light tobacco smokers). A stratified randomization method will be used to control for gender and tobacco-smoker status. It is hypothesized that MJ withdrawal symptoms will be less severe in the group assigned to the 7 mg patch than in the group assigned to the placebo. It is also hypothesized that individuals high in anxiety/neuroticism and those high in aggression/hostility will exhibit greater benefits from TNP than those low in these traits. Given that no gender differences were observed in our preliminary study, gender differences are not predicted. The over-the-counter availability, minimal abuse risks, and minimal adverse side-effects associated with TNP would make it an ideal and highly implementable treatment for MJ dependence if it can be demonstrated to be efficacious in reducing MJ withdrawal symptoms.

Inclusion Criteria: Female and male cannabis-dependent MJ smokers aged 18 years or older will be recruited. Inclusion criteria include cannabis dependence as assessed by a Diagnostic and Statistical Manual (DSM-IV)-based structured interview and MJ use on 10-28 occasions per week and be willing to abstain for 15 days. Only individuals who are in good mental and physical health, with a BMI of 17-30 kg/m2, as verified by health questionnaires and the Structured Clinical Interview for DSM-IV (SCID), will participate in this study. Potential subjects will be asked to indicate, on a scale of 1-10, how strong they currently want to quit smoking MJ (from "1" = "not at all" to "10" = "very strong") and will also be assessed with the four-item MJ Stages of Change. Additionally, subjects will fulfill one of two criteria: 1) not smoke or use other tobacco products or 2) smoke tobacco cigarettes or use other nicotine delivery systems (e.g., hookah, cigars, chewing tobacco) fewer than 5 times per day (on average) for the past year. Current use of MJ and tobacco will be verified by detectable urine Tetrahydrocannabinol (THC) and nicotine metabolites. All subjects will be required to provide four pre-quit baseline urine samples. The mean creatinine-normalized THC concentration across these samples must be of 175 ng/ml or greater based. -

Exclusion Criteria:

Criteria include meeting DSM-IV criteria for current abuse or dependence on a substance other than MJ, nicotine, or caffeine, using psychoactive substances (other than MJ, alcohol, nicotine, & caffeine) 6+ times/month, testing positive for stimulants, antidepressants, anxiolytics, and/or opiates (10-panel urine drug test), testing above a salivary cotinine concentration of 150 ng/ml during the initial screening, using creatinine or creatinine-containing supplements, testing positive for adulteration of urine samples, consuming more than 6 alcoholic drinks per day continuously for a month, mental disorders including bipolar disorder, schizophrenia, psychotic symptoms, currently, recently, or ever chronically at significant suicidal risk or experiencing violent thoughts or current major depression. Others that will be excluded include women who are pregnant, lactating, not taking precautions to avoid pregnancy, individuals with significant physical disorders or unstable physical disorders that may represent a severe untreated condition, such as hypertension, as well as those with less than a high school education or equivalent, primary language other than English, and those with significant cognitive impairment.

The modest sample size limited the ability to precisely characterize how the effects of patch type may be modified by tobacco smoker status, gender, personality traits, and individual differences in marijuana use history.